Sound Practices Mailing List Files - Volume 2
=========================================================================
From: "Multi-Volti Devices" <multi-volti@softhouse.com>
Subject: [JN] M4 iron
Date: Tue, 13 Jul 1999 02:34:57 -0400
Source: Sound Digest Archive v02.n204
Could someone please tell me if M4 is a commonly available material in EI
laminations, and if it is a steel or a nickel material?
I can easily get M6 and some other thinner higher performance (or at least
cost) materials, but they have proprietary names that do not allude to the
suggestion that M4 has lower losses than M6 (maybe I'm jumping to
comclusions because the '6' in M6 is a reference to it's losses.)
I haven't looked very hard yet for nickel in EI, but my initial eforts were
thwarted. C-core in nickel, no problem, but haven't found Ni in the sizes I
wanted (EI 125)
Thanks
Murray
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: [JN] M4 iron
Date: Tue, 13 Jul 99 10:00:02 -0400
Source: Sound Digest Archive v02.n204
Murray,
>Could someone please tell me if M4 is a commonly available material in EI
>laminations, and if it is a steel or a nickel material?
M4 is common steel and available for a premium. Also M2 and M3, though
harder to use because of it's softness.
>I haven't looked very hard yet for nickel in EI, but my initial eforts were
>thwarted. C-core in nickel, no problem, but haven't found Ni in the sizes I
>wanted (EI 125)
Nickel is readily avialble in EI form. But why use it unless you are
doing parafeed?
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.WavelengthAudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: Joe Roberts <jroberts@io.com>
Subject: [JN] Mac CAD software
Date: Tue, 25 Jul 2000 20:25:02 -0500
Source: Sound Digest Archive v02.n609
Can anybody recommend a decent mid-grade CAD program for Mac? Need to
generate some .dxf files for metal work.
Any suggestions appreciated. Even my Mac man, Gordon Rankin, couldn't
come up with a worthy path.
Thanks.
Joe "of Joenet Fame"
=========================================================================
From: "James Thompson" <jthompso@yazaki-na.com>
Subject: Re: [JN] Mac CAD software
Date: Wed, 26 Jul 2000 07:40:09 -0400
Source: Sound Digest Archive v02.n609
Hey Joe,
Pick up a "copy" of Autocad 13 or 14. It's pretty complex but good for basic work also. I use it to
export .dxf files to a graphics plotter for making large labels for equipment. I don't know if they
make a Mac version.
Jim
>>> Joe Roberts <jroberts@io.com> 07/25/00 09:25PM >>>
Can anybody recommend a decent mid-grade CAD program for Mac? Need to
generate some .dxf files for metal work.
=========================================================================
From: David Barnett <d_n_b@swbell.net>
Subject: Re: [JN] Mac CAD software
Date: Wed, 26 Jul 2000 09:24:43 -0500
Source: Sound Digest Archive v02.n610
On Wed, 26 Jul 2000 07:40:09 -0400, James Thompson
<jthompso@yazaki-na.com> wrote:
> I don't know if they make a Mac version.
Nope
- --dnb
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: Re: [JN] Re: Mac CAD software
Date: Wed, 26 Jul 2000 10:14:24 -0700
Source: Sound Digest Archive v02.n610
>I don't know if MiniCad / VectorWorks qualifies as a mid-range
>program, but certainly the recent versions do have some dxf.
>capabilities.
All vesions of MiniCad i've used (going back a long way) have dxf
export/import. From version 7 on (current is 8.5) also support DWG in/out.
BTW: this is WAY better software than AutoCAD, and the cost differential is
such that you have enuff money left-over vis-a-vis buying AutoCAD that you
can buy a modest PowerMac to run it on. Over 50% of the architects in our
fair city use this software -- the local IBM building was architected on
Macs using a very early version of MiniCad.
The Mini part dates from an era when there were mini-computers and the name
was intended to signify mini-computer power on a micro-computer. The name
is no longer germain so they have changed the name to VectorWorks.
>For pure format conversions, there is also CADMover.
CADMover is a very specialized and sometimes finiky sw and i recommend it
only if you have a task to achieve that it can really do and will pay for
it on that single job.
dave
______________________
Moore Associates
250 386 7370
mostly Macintosh
service oriented VAR
=========================================================================
From: Tim Reese <tgrmail@nmr.MGH.harvard.EDU>
Subject: Re: [JN] Mac CAD software
Date: Wed, 26 Jul 2000 14:09:13 -0400 (EDT)
Source: Sound Digest Archive v02.n610
Joe wrote
>Can anybody recommend a decent mid-grade CAD program for Mac? Need to
>generate some .dxf files for metal work.
>
>Any suggestions appreciated. Even my Mac man, Gordon Rankin, couldn't
>come up with a worthy path.
No personal experience with these products, but try Douglas Electronics
http://www.douglas.com/services/manufacturing/sheetmetal.html
which offers a freeware layout program and a $200 dxf converter utility.
I will download the freeware and try it out...
hth tr
- ----------------------------------------------------------------------
Visit http://www.nmr.MGH.harvard.edu/~reese MRI, tube audio, reptiles
Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: Re: [JN] Mac CAD software
Date: Wed, 26 Jul 2000 15:40:17 -0400
Source: Sound Digest Archive v02.n610
James suggests:
>>> Pick up a "copy" of Autocad 13 or 14. It's pretty complex but good for
basic work also. I use it to export .dxf files to a graphics plotter for
making large labels for equipment. I don't know if they make a Mac
version<<<
They used to, and IMO they suck! AutoCad is NOT a user friendly pgm by any
stretch of the imagination, and it was never a commercial success ported
over to the Mac, when used by typically right brained Mac users.
Like what a hideous non intuitive, non Mac p
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: Re: [JN] Mac CAD software
Date: Wed, 26 Jul 2000 15:41:16 -0400
Source: Sound Digest Archive v02.n610
James suggests:
>>> Pick up a "copy" of Autocad 13 or 14. It's pretty complex but good for
basic work also. I use it to export .dxf files to a graphics plotter for
making large labels for equipment. I don't know if they make a Mac
version<<<
They used to, and IMO they suck! AutoCad is NOT a user friendly pgm by any
stretch of the imagination, and it was never a commercial success ported
over to the Mac, when used by typically right brained Mac users.
Like what a hideous non intuitive, non Mac pgm! It is a lession in how NOT
to make a Mac pgm...the company dropped the Mac versions after AutoCAD 13
or so, and I say "Who cares?"
There is also TurboCAD for Mac, another PC portover that got really good
reviews as it is apparently very powerful, and was really cheap. It may be
great for solid left-brainers, but I tossed it on that pile in the back
room after a frustrating day of trying...
I'd say to go with DaveD's advice to use MiniCAD - it's 100% Mac intended,
and while a very serious pgm is almost as easy to learn (at least it's
basics) as is ClarisCAD - which is the kindergarten pgm I use for my
metalwork and schematics, but has no fancy export file formats.
Allen (VSE)
=========================================================================
From: connlyra@gol.com
Subject: [JN] Re: Mac CAD software
Date: Thu, 27 Jul 2000 01:17:20 +0900
Source: Sound Digest Archive v02.n610
Joe,
>Can anybody recommend a decent mid-grade CAD program for Mac? Need
>to generate some .dxf files for metal work.<
I don't know if MiniCad / VectorWorks qualifies as a mid-range
program, but certainly the recent versions do have some dxf.
capabilities.
For pure format conversions, there is also CADMover.
jonathan carr
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: Re: [JN] Mac EDA software list
Date: Fri, 12 Nov 1999 15:54:09 -0800
Source: Sound Digest Archive v02.n331
>1. I consistently hear some very nice things about Beige Bag (B2
>Spice and B2 Logic) from a number of people.
I have this and it works nicely. The schematic editor UI could use some
real polishing
6. Mac-the-Scope. I have this program but haven't really given it the
exercise it is due. The original market was to a large extent medical &
speech therapy. I have been talking to him about features for the audio
community. V3 (anyday now) has some enhancements in this direction and i
think after AES he sees a whole new vertical market. ie keep your eye on
this one.
One thing i can say is that it runs really nicely on my PowerBook which
means i have a portable, battery powered measuring tool
>Overall, however, I find that there is a better choice of EDA
>software on the PC than on the Mac (there are some new Linux packages
>that may be worth looking into - http://www.geda.seul.org/ ).
One hopes that with the release of OS X (January?) we will see UNIX based
software being ported to the new UNIX based MacOS (OS X should very quickly
become the UNIX with the largest installed base)
__________________
Transmission Line Speaker Page
http://139.142.118.15/sites/diy
=========================================================================
From: connlyra@gol.com
Subject: [JN] Mac EDA software list
Date: Sat, 13 Nov 1999 08:16:52 +0900
Source: Sound Digest Archive v02.n331
Hi all,
For those who prefer to use a Mac for most of their computing work
and would also like to use it for electronic design work (schematic
capture, device modeling, circuit simulation, pcb layout, finline
simulation etc), Mac Central currently has an article on Macintosh
EDA software:
http://www.maccentral.com/news/9911/12.migrationkit.shtml
Also, if there is a software package which you use and which is not
mentioned at the above url, I assume that Mac Central would like to
know about it.
Of the packages mentioned:
1. I consistently hear some very nice things about Beige Bag (B2
Spice and B2 Logic) from a number of people.
2. EWB is quite easy to use (especially the schematic capture module)
and very good for monitoring current and voltage levels but otherwise
not especially flexible, powerful nor accurate (at least, not in my
hands).
3. The full version of MicroCap V is ok overall to use but given what
it can do, pricey (I have not used the student edition nor version
IV).
4. Spice is the grandaddy of all but a regal PITA to learn and use.
5. PSpice is perhaps the most flexible and powerful overall but has a
steep learning curve (and I wish its schematic editor were as easy to
use as EWB).
Overall, however, I find that there is a better choice of EDA
software on the PC than on the Mac (there are some new Linux packages
that may be worth looking into - http://www.geda.seul.org/ ).
I currently do most of my work on Win98 or NT4 using PSpice 5.2 or
7.1 (the built-in schematic capture module has been replaced with
ECS, plus TextPad 3.2 for netlist editing - much better than NotePad
or WordPad) and Protel98 (pretty good for pcb layouts, so-so for
schematic editing, and downright lousy at simulation) - although I
sometimes use MicroCap or EWB when I just want quick results and the
circuit is simple.
Hope this helps
jc
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: [JN] Mac software
Date: Wed, 26 Jul 2000 15:40:12 -0400
Source: Sound Digest Archive v02.n610
Hi All,
While talking about Mac pgms - anyone out there got a copy of that
Mac pgm that calculates the optimum position for a speaker in a room?
Off line replies please. Will trade...
Allen (VSE)
=========================================================================
From: Paul Joppa <pj@bottlehead.com>
Subject: Re: [JN]Madness ... I quit
Date: Mon, 17 Sep 2001 10:24:12 -0700
Source: Sound Digest Archive v02.n976
All-
Sorry, but I can't absorb this stuff anymore. I am leaving this
list for a while.
Peace and love,
- -Paul Joppa
=========================================================================
From: "Daniel Dicker" <dbdicker@worldnet.att.net>
Subject: Re: [JN]Madness ... I quit
Date: Mon, 17 Sep 2001 18:50:08 -0400
Source: Sound Digest Archive v02.n977
I'm with you Paul -- I'm outta here.....
You all should be ashamed of yourselves....and for those of you who don't
know you should be ashamed....I pity you.....
Peace,
Dan
- ----- Original Message -----
From: "Paul Joppa" <pj@bottlehead.com>
To: <sound@lists.io.com>
Sent: Monday, September 17, 2001 1:24 PM
Subject: Re: [JN]Madness ... I quit
> All-
>
> Sorry, but I can't absorb this stuff anymore. I am leaving this
> list for a while.
>
> Peace and love,
> -Paul Joppa
>
=========================================================================
From: Carter Hendricks <carter@i1.net>
Subject: Re: [JN]Madness ... I quit
Date: Mon, 17 Sep 2001 22:03:40 -0500
Source: Sound Digest Archive v02.n977
Paul wrote:
>
> Sorry, but I can't absorb this stuff anymore.
I missed most of the braking dogs noise by
using filters. Fun! when mail from a
barking dog arrives, it is automatically
deleted. Poof! I think there are tools in
every mail program to filter incoming messages.
--Carter
=========================================================================
From: "Bill Sadler" <sadlerb@mweb.co.za>
Subject: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 22:23:42 +0200
Source: Sound Digest Archive v02.n971
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Hello Joes
I can't believe some of the statements being made on the list especially =
the anti-Israel sentiment, all of this born out of a total ignorance of =
the history of the land of Israel, or is it just anti-American and =
anti-any body who is seen to be friendly with the US.
I am not Jewish or have any links to the Jewish people so I have no axe =
to grind in favour of anybody other than to stand up for the truth. And =
I submit below an extract from the letters of Dr Martin Luther King Jr =
(New York, 1971) pp 234-235.=20
FROM MARTIN LUTHER KING JR "LETTER TO AN ANTI-ZIONIST FRIEND" (AUG =
1967)
"anti-Semitism, the hatred of the Jewish people, has been and remains a =
blot on the soul of mankind. In this we are in full agreement. So know =
also this: anti-Zionist is inherently anti-Semitic (racist) and ever =
will be so.
"Why is this? You know that Zionism is nothing less than the dream and =
ideal of the Jewish people returning to live in their own land. The =
Jewish people, the Scriptures tell us, once enjoyed a flourishing =
Commonwealth in the Holy Land. From this they were expelled by the =
Roman tyrant, the same Roman who cruelly murdered Our Lord.. Driven =
from their homeland, their nation in ashes, forced to wonder the globe, =
the Jewish people time and again suffered the lash of whichever tyrant =
happened to rule over them.
"The Negro people, my friend, know what it is to suffer the torment of =
tyranny under rulers not of our choosing. Our brothers in Africa have =
begged, pleaded, requested - demanded the recognition and realization of =
our inborn right to live in peace under our own sovereignty in our own =
country.
"How easy it should be, for anyone who holds dear this inalienable right =
of all mankind, to understand and support the right of the Jewish people =
to live in their ancient Land of Israel. All men of goodwill exult in =
the fulfillment of God's promise, that his People should return in joy =
to rebuild their plundered land. This is Zionism, nothing more, nothing =
less.
"And what is anti-Zionist? It is the denial to the Jewish people of a =
fundamental right that we justly claim for the people of Africa and =
freely accord all other nations of the Globe. It is discrimination =
against Jews, my friend, because they are Jews. In short, it is =
anti-Semitism.
The anti-Semite rejoices at any opportunity to vent his malice. The =
times have made it unpopular, in the West, to proclaim openly a hatred =
of the Jews. This being the case, the anti-Semite must constantly seek =
new forms and forums for his poison. How he must revel in the new =
masquerade' He does not hate the Jews, he is just anti-Zionist'
"My friend, I do not accuse you of deliberate anti-Semitism, I know you =
feel as I do, a deep love of truth and justice and revulsion for racism, =
prejudice and discrimination. But I know you have been misled as others =
have been - into thinking you can be anti-Zionist and yet remain true to =
these heartfelt principles that you and I share. Let my words echo in =
the depths of your soul: When people criticize Zionism, they mean Jews =
- - make no mistake about it."
America has recognized the right of the Jewish people to return to their =
homeland and is therefore supporting them in this endeavor even if it =
means displacing some Arabs who opportunistically moved into Israel when =
the Jews where kicked out.
Bill
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<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4134.600" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2><STRONG>Hello =
Joes</STRONG></FONT></DIV>
<DIV><STRONG><FONT face=3DArial size=3D2></FONT></STRONG> </DIV>
<DIV><FONT face=3DArial size=3D2>I can't believe some of the statements =
being made=20
on the list especially the anti-Israel sentiment, all of this born out =
of a=20
total ignorance of the history of the land of Israel, or is it just=20
anti-American and anti-any body who is seen to be friendly with the=20
US.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>I am not Jewish or have any links to=20
the Jewish people so I have no axe to grind in favour of =
anybody other=20
than to stand up for the truth. And I submit below an extract from the =
letters=20
of Dr Martin Luther King Jr (New York, 1971) pp =
234-235.</FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><STRONG></STRONG></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><STRONG>FROM MARTIN LUTHER KING =
JR "LETTER TO=20
AN ANTI-ZIONIST FRIEND" (AUG 1967)</STRONG></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><STRONG></STRONG></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"anti-Semitism, the hatred of the =
Jewish people,=20
has been and remains a blot on the soul of mankind. In this we are =
in full=20
agreement. So know also this: anti-Zionist is inherently=20
anti-Semitic (racist) and ever will be so.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"Why is this? You know that =
Zionism is=20
nothing less than the dream and ideal of the Jewish people returning to =
live in=20
their own land. The Jewish people, the Scriptures tell us, once=20
enjoyed a flourishing Commonwealth in the Holy Land. From =
this they=20
were expelled by the Roman tyrant, the same Roman who cruelly murdered =
Our=20
Lord.. Driven from their homeland, their nation in ashes, forced =
to wonder=20
the globe, the Jewish people time and again suffered the lash of =
whichever=20
tyrant happened to rule over them.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"The Negro people, my friend, know what =
it is to=20
suffer the torment of tyranny under rulers not of our choosing. =
Our=20
brothers in Africa have begged, pleaded, requested - demanded the =
recognition=20
and realization of our inborn right to live in peace under our own =
sovereignty=20
in our own country.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"How easy it should be, for anyone who =
holds dear=20
this inalienable right of all mankind, to understand and support the =
right of=20
the Jewish people to live in their ancient Land of Israel. All men =
of=20
goodwill exult in the fulfillment of God's promise, that his People =
should=20
return in joy to rebuild their plundered land. This is Zionism, =
nothing=20
more, nothing less.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>"And what is anti-Zionist? It is =
the denial=20
to the Jewish people of a fundamental right that we justly claim for the =
people=20
of Africa and freely accord all other nations of the Globe. It is =
discrimination=20
against Jews, my friend, because they are Jews. In short, it is=20
anti-Semitism.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>The anti-Semite rejoices at any =
opportunity to vent=20
his malice. The times have made it unpopular, in the West, to =
proclaim=20
openly a hatred of the Jews. This being the case, the anti-Semite =
must=20
constantly seek new forms and forums for his poison. How he must =
revel in=20
the new masquerade' He does not hate the Jews, he is just=20
anti-Zionist'</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>"My friend, I do not accuse you of =
deliberate=20
anti-Semitism, I know you feel as I do, a deep love of truth and justice =
and=20
revulsion for racism, prejudice and discrimination. But I know you =
have=20
been misled as others have been - into thinking you can be anti-Zionist =
and yet=20
remain true to these heartfelt principles that you and I share. =
Let my=20
words echo in the depths of your soul: When people criticize =
Zionism, they=20
mean Jews - make no mistake about it."</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>America has recognized the right of the =
Jewish=20
people to return to their homeland and is therefore supporting them in =
this=20
endeavor even if it means displacing some Arabs who opportunistically =
moved into=20
Israel when the Jews where kicked out.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Bill</FONT></DIV></BODY></HTML>
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=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: Re: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 15:31:02 -0600 (MDT)
Source: Sound Digest Archive v02.n972
On Fri, 14 Sep 2001, Bill Sadler wrote:
> Hello Joes
>
> I can't believe some of the statements being made on the list
> especially the anti-Israel sentiment, all of this born out of a total
> ignorance of the history of the land of Israel, or is it just
> anti-American and anti-any body who is seen to be friendly with the
> US. I am not Jewish or have any links to the Jewish people so I have
> no axe to grind in favour of anybody other than to stand up for the
> truth. And I submit below an extract from the letters of Dr Martin
> Luther King Jr (New York, 1971) pp 234-235.
One can find objection to the conduct and policies of Israel without being
anti-Semitic. Ascribing prejudice to anyone who would criticize either
Israel or those who abet its behavior is a familiar ad hominem tactic that
avoids considering the merits of an argument by attacking its presenter.
It was a trick used to stifle dissent from the capitalist/corporate course
America set for itself in the wake of the conquest of the Great Depression
of the thirties, which we shot our way out of in WWII via deficit
spending. The trick imploded when Senator Joseph McCarthy unwittingly
revealed it for what it is. It is a means simply of avoiding scrutiny.
I note, in passing, that so trite and mantra-like has the accusation
become that its users seem not to realize that the very Arabs demoted to
the status of scabs on the body politic of Israel are themselves Semites,
as are most of the residents of the Levant.
But let us leave aside the issue of the absolute virtue of Israel. The
point I attempted to make yesterday is that America is widely perceived by
Arab peoples as holding them to severe standards of conduct and exempting
the state of Israel not just from examination but more importantly from
accountability. I could believe their belief completely erroneous, but it
would not change their perception, nor more importantly their increasing
desperation after half a century of American sponsorship of Israel that
Arab peoples will not receive justice from us, particularly the
disenfranchised Palestinian Arabs. If payment for a bill for the
pro-Israeli policies of America is to be exacted by Arabic terrorists, it
may be appropriate in a democracy for us to undertake a full and fair
debate.
I wish not one more person to die. I regret the deaths of Palestinian,
Jew, Arab, or American. I would hope to break the endless cycle of
violence by calm examination rather than sloganeering, rabble-rousing, or
jingoism. I hold it as self-evident that all men are equal and all men
deserve the same justice.
If accountability is to be the order of the day, I want all parties
subjected to scrutiny. That means, perhaps, holding America accountable
for sanctioning injustice among those peoples who feel so desperate about
their plight that they would commit suicide in order either to gain some
measure of revenge, or on higher moral ground, to shock their tormentors
into re-examining their own conduct.
Perhaps you can explain why Israel should be exempted from criticism or
discussion.
Doug Purl
=========================================================================
From: "Phil Sieg" <triodelover@home.com>
Subject: Re: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 16:48:34 -0400
Source: Sound Digest Archive v02.n972
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Bill,
Thanks for reminding us of the words of a great American. Dr King is =
right. But I would suggest that you duck-and-cover, for those Americans =
expressing anti-Zionist sentiments on this list will not be pleased with =
your choice of messenger.
Phil
----- Original Message -----=20
From: Bill Sadler=20
To: Joe Net=20
Sent: Friday, 14 September, 2001 16.23
Subject: [JN] re: Madness on the Joe List
Hello Joes
I can't believe some of the statements being made on the list =
especially the anti-Israel sentiment, all of this born out of a total =
ignorance of the history of the land of Israel, or is it just =
anti-American and anti-any body who is seen to be friendly with the US.
I am not Jewish or have any links to the Jewish people so I have no =
axe to grind in favour of anybody other than to stand up for the truth. =
And I submit below an extract from the letters of Dr Martin Luther King =
Jr (New York, 1971) pp 234-235.=20
FROM MARTIN LUTHER KING JR "LETTER TO AN ANTI-ZIONIST FRIEND" (AUG =
1967)
"anti-Semitism, the hatred of the Jewish people, has been and remains =
a blot on the soul of mankind. In this we are in full agreement. So =
know also this: anti-Zionist is inherently anti-Semitic (racist) and =
ever will be so.
"Why is this? You know that Zionism is nothing less than the dream =
and ideal of the Jewish people returning to live in their own land. The =
Jewish people, the Scriptures tell us, once enjoyed a flourishing =
Commonwealth in the Holy Land. From this they were expelled by the =
Roman tyrant, the same Roman who cruelly murdered Our Lord.. Driven =
from their homeland, their nation in ashes, forced to wonder the globe, =
the Jewish people time and again suffered the lash of whichever tyrant =
happened to rule over them.
"The Negro people, my friend, know what it is to suffer the torment of =
tyranny under rulers not of our choosing. Our brothers in Africa have =
begged, pleaded, requested - demanded the recognition and realization of =
our inborn right to live in peace under our own sovereignty in our own =
country.
"How easy it should be, for anyone who holds dear this inalienable =
right of all mankind, to understand and support the right of the Jewish =
people to live in their ancient Land of Israel. All men of goodwill =
exult in the fulfillment of God's promise, that his People should return =
in joy to rebuild their plundered land. This is Zionism, nothing more, =
nothing less.
"And what is anti-Zionist? It is the denial to the Jewish people of a =
fundamental right that we justly claim for the people of Africa and =
freely accord all other nations of the Globe. It is discrimination =
against Jews, my friend, because they are Jews. In short, it is =
anti-Semitism.
The anti-Semite rejoices at any opportunity to vent his malice. The =
times have made it unpopular, in the West, to proclaim openly a hatred =
of the Jews. This being the case, the anti-Semite must constantly seek =
new forms and forums for his poison. How he must revel in the new =
masquerade' He does not hate the Jews, he is just anti-Zionist'
"My friend, I do not accuse you of deliberate anti-Semitism, I know =
you feel as I do, a deep love of truth and justice and revulsion for =
racism, prejudice and discrimination. But I know you have been misled =
as others have been - into thinking you can be anti-Zionist and yet =
remain true to these heartfelt principles that you and I share. Let my =
words echo in the depths of your soul: When people criticize Zionism, =
they mean Jews - make no mistake about it."
America has recognized the right of the Jewish people to return to =
their homeland and is therefore supporting them in this endeavor even if =
it means displacing some Arabs who opportunistically moved into Israel =
when the Jews where kicked out.
Bill
- ------=_NextPart_000_0036_01C13D3D.17AD0940
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charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4134.600" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>Bill,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Thanks for reminding us of the words of =
a great=20
American. Dr King is right. But I would suggest that you=20
duck-and-cover, for those Americans expressing anti-Zionist sentiments =
on this=20
list will not be pleased with your choice of messenger.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Phil</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dsadlerb@mweb.co.za href=3D"mailto:sadlerb@mweb.co.za">Bill =
Sadler</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dsound@lists.io.com=20
href=3D"mailto:sound@lists.io.com">Joe Net</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Friday, 14 September, =
2001=20
16.23</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [JN] re: Madness on =
the Joe=20
List</DIV>
<DIV><BR></DIV>
<DIV><FONT face=3DArial size=3D2><STRONG>Hello =
Joes</STRONG></FONT></DIV>
<DIV><STRONG><FONT face=3DArial size=3D2></FONT></STRONG> </DIV>
<DIV><FONT face=3DArial size=3D2>I can't believe some of the =
statements being made=20
on the list especially the anti-Israel sentiment, all of this born out =
of a=20
total ignorance of the history of the land of Israel, or is it just=20
anti-American and anti-any body who is seen to be friendly with the=20
US.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>I am not Jewish or have any links to=20
the Jewish people so I have no axe to grind in favour of =
anybody=20
other than to stand up for the truth. And I submit below an extract =
from the=20
letters of Dr Martin Luther King Jr (New York, 1971) pp=20
234-235.</FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><STRONG></STRONG></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><STRONG>FROM MARTIN LUTHER KING =
JR "LETTER=20
TO AN ANTI-ZIONIST FRIEND" (AUG 1967)</STRONG></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><STRONG></STRONG></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"anti-Semitism, the hatred of the =
Jewish people,=20
has been and remains a blot on the soul of mankind. In this we =
are in=20
full agreement. So know also this: anti-Zionist is =
inherently=20
anti-Semitic (racist) and ever will be so.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"Why is this? You know that =
Zionism is=20
nothing less than the dream and ideal of the Jewish people returning =
to live=20
in their own land. The Jewish people, the Scriptures tell us, =
once=20
enjoyed a flourishing Commonwealth in the Holy Land. From =
this=20
they were expelled by the Roman tyrant, the same Roman who cruelly =
murdered=20
Our Lord.. Driven from their homeland, their nation in ashes, =
forced to=20
wonder the globe, the Jewish people time and again suffered the lash =
of=20
whichever tyrant happened to rule over them.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"The Negro people, my friend, know =
what it is to=20
suffer the torment of tyranny under rulers not of our choosing. =
Our=20
brothers in Africa have begged, pleaded, requested - demanded the =
recognition=20
and realization of our inborn right to live in peace under our own =
sovereignty=20
in our own country.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>"How easy it should be, for anyone =
who holds dear=20
this inalienable right of all mankind, to understand and support the =
right of=20
the Jewish people to live in their ancient Land of Israel. All =
men of=20
goodwill exult in the fulfillment of God's promise, that his People =
should=20
return in joy to rebuild their plundered land. This is Zionism, =
nothing=20
more, nothing less.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>"And what is anti-Zionist? It =
is the denial=20
to the Jewish people of a fundamental right that we justly claim for =
the=20
people of Africa and freely accord all other nations of the Globe. It =
is=20
discrimination against Jews, my friend, because they are Jews. =
In short,=20
it is anti-Semitism.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>The anti-Semite rejoices at any =
opportunity to=20
vent his malice. The times have made it unpopular, in the West, =
to=20
proclaim openly a hatred of the Jews. This being the case, the=20
anti-Semite must constantly seek new forms and forums for his =
poison. =20
How he must revel in the new masquerade' He does not hate the =
Jews, he=20
is just anti-Zionist'</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>"My friend, I do not accuse you of =
deliberate=20
anti-Semitism, I know you feel as I do, a deep love of truth and =
justice and=20
revulsion for racism, prejudice and discrimination. But I know =
you have=20
been misled as others have been - into thinking you can be =
anti-Zionist and=20
yet remain true to these heartfelt principles that you and I =
share. Let=20
my words echo in the depths of your soul: When people criticize =
Zionism,=20
they mean Jews - make no mistake about it."</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>America has recognized the right of =
the Jewish=20
people to return to their homeland and is therefore supporting them in =
this=20
endeavor even if it means displacing some Arabs who opportunistically =
moved=20
into Israel when the Jews where kicked out.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial =
size=3D2>Bill</FONT></DIV></BLOCKQUOTE></BODY></HTML>
- ------=_NextPart_000_0036_01C13D3D.17AD0940--
=========================================================================
From: ToobWiz@aol.com
Subject: Re: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 17:47:02 EDT
Source: Sound Digest Archive v02.n972
In a message dated 09/14/2001 5:<BR35:<BR10 PM
Eastern Daylight , dcp@selway.umt.edu writes:> One can find objection to the
conduct and policies of Israel without being
> anti-Semitic.
Bravo Paul,
for this and your very excellent followon statements. Please read my upcoming
post for information that will definitely help, if researched and accepted,
to further the "full and fari debate" that is long overdue.
I was treated some years ago to a 70-mile taxi ride the the AbuDhabi airport
with a Palestinian taxi driver. Believe me, I came home and did grinding
research into the history of the Levant as well as a good deal of geneology.
Cheers/Don cArron
=========================================================================
From: "Michael D. Schleif" <mds@helices.org>
Subject: Re: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 17:44:44 -0500
Source: Sound Digest Archive v02.n973
> Bill Sadler wrote:
>
> America has recognized the right of the Jewish people to return to
> their homeland and is therefore supporting them in this endeavor even
> if it means displacing some Arabs who opportunistically moved into
> Israel when the Jews where kicked out.
It is exactly this sentiment -- noticeably *lacking* from Dr. King's
letters -- that maybe said to be the source of our current trauma.
No, I do not promote any anti-ism -- none. Never have, never will.
However, your use of the phrase ``opportunistically'' draws interesting
parallels to the usurpation of the Americas several hundred years ago.
Or, the Imperialization of much of Asia by certain western europeans
during similar times.
Also, notice that that land never stood vacant, so it is difficult for
me to understand how a people already there ``opportunistically moved
into'' it ???
Is it possible that that land -- or any land, does it matter? -- might
support multiple peoples? To wit, take a long hard look at our own
melting pots and the variety of peoples who, today, call themselves
Americans . . .
- --
Best Regards,
mds
mds resource
888.250.3987
Dare to fix things before they break . . .
Our capacity for understanding is inversely proportional to how much we
think we know. The more I know, the more I know I don't know . . .
=========================================================================
From: Phil <tube@jump.net>
Subject: Re: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 18:32:37 -0500
Source: Sound Digest Archive v02.n973
Phil Sieg wrote:
> Bill, Thanks for reminding us of the words of a great American. Dr
> King is right. But I would suggest that you duck-and-cover, for those
> Americans expressing anti-Zionist sentiments on this list will not be
> pleased with your choice of messenger. Phil
Phil,
So anybody who criticizes the *state* of Israel automatically hates
blacks, Jews, etc.? I had some Iranian roomates in the late 70's,
and while some of them hated the state of America, they did not hate
Americans at all. You keep labeling as racist anyone who thinks Israel
has done bad things. Do you really think that this "proves" that their
statements about Israel are incorrect?
I have to agree with Don, Doug, and others that while you obviously
have a very good mind, you insist on trying to win arguments by
declaring the other person to be racist, evil, a monster, etc. If Adolf
Hitler said that 2 + 2 = 4, would it really be necessary to get a new
system of arithmetic? Okay, they are all evil racist monsters. Now,
getting back to the subject, is what they said true or false?
I hate to say really bad things about you, but you remind me very
much of myself. When I was in high school, I said to the girl next
to me, "What am I, a philosopher, doing here in a math class?" She
looked at me for a minute, and then said, "No Phil, you're no
philosopher. Because a philosopher has to look at everything equally,
and you cut to shreds anyone who disagrees with you." Very few
weeks have gone by in the last 26 years, when I have not thought
of those words.
Maybe it's something about the name, "Phil"? But go ahead, just for
my amusement, show all of us your chains, prove that everything I
have said here is wrong ...
... by sending an email in which you cut me to shreds.
Need-a-new-name Phil
=========================================================================
From: "Phil Sieg" <triodelover@home.com>
Subject: Re: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 20:23:49 -0400
Source: Sound Digest Archive v02.n973
Phil,
All I can say is that you really haven't read what I have written. Try to
take in all I say and eschew the politically correct editing. My POV is far
different from your representation. An open mind is an important tool in
these times.
Phil
- ----- Original Message -----
From: "Phil" <tube@jump.net>
Cc: "Joe Net" <sound@lists.io.com>
Sent: Friday, 14 September, 2001 19.32
Subject: Re: [JN] re: Madness on the Joe List
> Phil Sieg wrote:
>
> > Bill, Thanks for reminding us of the words of a great American. Dr
> > King is right. But I would suggest that you duck-and-cover, for those
> > Americans expressing anti-Zionist sentiments on this list will not be
> > pleased with your choice of messenger. Phil
>
> Phil,
>
> So anybody who criticizes the *state* of Israel automatically hates
> blacks, Jews, etc.? I had some Iranian roomates in the late 70's,
> and while some of them hated the state of America, they did not hate
> Americans at all. You keep labeling as racist anyone who thinks Israel
> has done bad things. Do you really think that this "proves" that their
> statements about Israel are incorrect?
>
> I have to agree with Don, Doug, and others that while you obviously
> have a very good mind, you insist on trying to win arguments by
> declaring the other person to be racist, evil, a monster, etc. If Adolf
> Hitler said that 2 + 2 = 4, would it really be necessary to get a new
> system of arithmetic? Okay, they are all evil racist monsters. Now,
> getting back to the subject, is what they said true or false?
>
> I hate to say really bad things about you, but you remind me very
> much of myself. When I was in high school, I said to the girl next
> to me, "What am I, a philosopher, doing here in a math class?" She
> looked at me for a minute, and then said, "No Phil, you're no
> philosopher. Because a philosopher has to look at everything equally,
> and you cut to shreds anyone who disagrees with you." Very few
> weeks have gone by in the last 26 years, when I have not thought
> of those words.
>
> Maybe it's something about the name, "Phil"? But go ahead, just for
> my amusement, show all of us your chains, prove that everything I
> have said here is wrong ...
> ... by sending an email in which you cut me to shreds.
>
> Need-a-new-name Phil
>
>
>
>
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: Re: [JN] re: Madness on the Joe List
Date: Fri, 14 Sep 2001 22:19:58 -0400
Source: Sound Digest Archive v02.n974
- --------------3055E312E0F2C1C99221D1BC
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Martin Luther King, Jr??? Didn't I read somewhere about his ties with
Communism...or was I 'having a dream'.
Bill Sadler wrote:
> Hello Joes I can't believe some of the statements being made on the
> list especially the anti-Israel sentiment, all of this born out of a
> total ignorance of the history of the land of Israel, or is it just
> anti-American and anti-any body who is seen to be friendly with the
> US.I am not Jewish or have any links to the Jewish people so I have no
> axe to grind in favour of anybody other than to stand up for the
> truth. And I submit below an extract from the letters of Dr Martin
> Luther King Jr (New York, 1971) pp 234-235. FROM MARTIN LUTHER KING
> JR "LETTER TO AN ANTI-ZIONIST FRIEND" (AUG 1967) "anti-Semitism, the
> hatred of the Jewish people, has been and remains a blot on the soul
> of mankind. In this we are in full agreement. So know also this:
> anti-Zionist is inherently anti-Semitic (racist) and ever will be
> so. "Why is this? You know that Zionism is nothing less than the
> dream and ideal of the Jewish people returning to live in their own
> land. The Jewish people, the Scriptures tell us, once enjoyed a
> flourishing Commonwealth in the Holy Land. From this they were
> expelled by the Roman tyrant, the same Roman who cruelly murdered Our
> Lord.. Driven from their homeland, their nation in ashes, forced to
> wonder the globe, the Jewish people time and again suffered the lash
> of whichever tyrant happened to rule over them. "The Negro people, my
> friend, know what it is to suffer the torment of tyranny under rulers
> not of our choosing. Our brothers in Africa have begged, pleaded,
> requested - demanded the recognition and realization of our inborn
> right to live in peace under our own sovereignty in our own
> country. "How easy it should be, for anyone who holds dear this
> inalienable right of all mankind, to understand and support the right
> of the Jewish people to live in their ancient Land of Israel. All men
> of goodwill exult in the fulfillment of God's promise, that his People
> should return in joy to rebuild their plundered land. This is
> Zionism, nothing more, nothing less."And what is anti-Zionist? It is
> the denial to the Jewish people of a fundamental right that we justly
> claim for the people of Africa and freely accord all other nations of
> the Globe. It is discrimination against Jews, my friend, because they
> are Jews. In short, it is anti-Semitism. The anti-Semite rejoices at
> any opportunity to vent his malice. The times have made it unpopular,
> in the West, to proclaim openly a hatred of the Jews. This being the
> case, the anti-Semite must constantly seek new forms and forums for
> his poison. How he must revel in the new masquerade' He does not
> hate the Jews, he is just anti-Zionist'"My friend, I do not accuse you
> of deliberate anti-Semitism, I know you feel as I do, a deep love of
> truth and justice and revulsion for racism, prejudice and
> discrimination. But I know you have been misled as others have been -
> into thinking you can be anti-Zionist and yet remain true to these
> heartfelt principles that you and I share. Let my words echo in the
> depths of your soul: When people criticize Zionism, they mean Jews -
> make no mistake about it." America has recognized the right of the
> Jewish people to return to their homeland and is therefore supporting
> them in this endeavor even if it means displacing some Arabs who
> opportunistically moved into Israel when the Jews where kicked
> out. Bill
- --------------3055E312E0F2C1C99221D1BC
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Content-Transfer-Encoding: 7bit
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<body bgcolor="#FFFFFF">
Martin Luther King, Jr??? Didn't I read somewhere about his ties
with Communism...or was I 'having a dream'.
<p>Bill Sadler wrote:
<blockquote TYPE=CITE><style></style>
<b><font face="Arial"><font size=-1>Hello
Joes</font></font></b> <font face="Arial"><font size=-1>I can't believe
some of the statements being made on the list especially the anti-Israel
sentiment, all of this born out of a total ignorance of the history of
the land of Israel, or is it just anti-American and anti-any body who is
seen to be friendly with the US.</font></font><font face="Arial"><font size=-1>I
am not Jewish or have any links to the Jewish people so I have no axe to
grind in favour of anybody other than to stand up for the truth. And I
submit below an extract from the letters of Dr Martin Luther King Jr (New
York, 1971) pp 234-235.</font></font> <b><font face="Arial"><font size=-1>FROM
MARTIN LUTHER KING JR "LETTER TO AN ANTI-ZIONIST FRIEND" (AUG
1967)</font></font></b> <font face="Arial"><font size=-1>"anti-Semitism,
the hatred of the Jewish people, has been and remains a blot on the soul
of mankind. In this we are in full agreement. So know also
this: anti-Zionist is inherently anti-Semitic (racist) and ever will
be so.</font></font> <font face="Arial"><font size=-1>"Why is this?
You know that Zionism is nothing less than the dream and ideal of the Jewish
people returning to live in their own land. The Jewish people, the
Scriptures tell us, once enjoyed a flourishing Commonwealth in the
Holy Land. From this they were expelled by the Roman tyrant, the
same Roman who cruelly murdered Our Lord.. Driven from their homeland,
their nation in ashes, forced to wonder the globe, the Jewish people time
and again suffered the lash of whichever tyrant happened to rule over them.</font></font> <font
face="Arial"><font size=-1>"The
Negro people, my friend, know what it is to suffer the torment of tyranny
under rulers not of our choosing. Our brothers in Africa have begged,
pleaded, requested - demanded the recognition and realization of our inborn
right to live in peace under our own sovereignty in our own country.</font></font> <font face="
Arial"><font size=-1>"How
easy it should be, for anyone who holds dear this inalienable right of
all mankind, to understand and support the right of the Jewish people to
live in their ancient Land of Israel. All men of goodwill exult in
the fulfillment of God's promise, that his People should return in joy
to rebuild their plundered land. This is Zionism, nothing more, nothing
less.</font></font><font face="Arial"><font size=-1>"And what is anti-Zionist?
It is the denial to the Jewish people of a fundamental right that we justly
claim for the people of Africa and freely accord all other nations of the
Globe. It is discrimination against Jews, my friend, because they are Jews.
In short, it is anti-Semitism.</font></font> <font face="Arial"><font size=-1>The
anti-Semite rejoices at any opportunity to vent his malice. The times
have made it unpopular, in the West, to proclaim openly a hatred of the
Jews. This being the case, the anti-Semite must constantly seek new
forms and forums for his poison. How he must revel in the new masquerade'
He does not hate the Jews, he is just anti-Zionist'</font></font><font face="Arial"><font size=-1>"M
y
friend, I do not accuse you of deliberate anti-Semitism, I know you feel
as I do, a deep love of truth and justice and revulsion for racism, prejudice
and discrimination. But I know you have been misled as others have
been - into thinking you can be anti-Zionist and yet remain true to these
heartfelt principles that you and I share. Let my words echo in the
depths of your soul: When people criticize Zionism, they mean Jews
- - make no mistake about it."</font></font> <font face="Arial"><font size=-1>America
has recognized the right of the Jewish people to return to their homeland
and is therefore supporting them in this endeavor even if it means displacing
some Arabs who opportunistically moved into Israel when the Jews where
kicked out.</font></font> <font face="Arial"><font size=-1>Bill</font></font></blockquote
>
</body>
</html>
- --------------3055E312E0F2C1C99221D1BC--
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: Re: [JN] re: Madness on the Joe List
Date: Sat, 15 Sep 2001 02:15:40 -0400
Source: Sound Digest Archive v02.n974
Oh Bob, don't you just WISH you could suspend the 1st Amendment on people 'like
me'.
BobC wrote:
> Please stop your bullshit! Things are bad enough already. Go iron your sheet
> and find something to sell on Ebay!...
>
> ----- Original Message -----
> From: Steve Van Osdell
> To: Bill Sadler
> Cc: Joe Net
> Sent: Friday, September 14, 2001 10:19 PM
> Subject: Re: [JN] re: Madness on the Joe List
>
> Martin Luther King, Jr??? Didn't I read somewhere about his ties with
> Communism...or was I 'having a dream'.
=========================================================================
From: "Phil Sieg" <triodelover@home.com>
Subject: Re: [JN] re: Madness on the Joe List
Date: Sat, 15 Sep 2001 10:00:18 -0400
Source: Sound Digest Archive v02.n974
Steve,
I don't and I doubt Bob does either. But defending your right to spout
bilge doesn't mean we have to like listening to it.
Phil
- ----- Original Message -----
From: "Steve Van Osdell" <svanos@queencity.com>
To: "BobC" <bobcx@nyc.rr.com>; "Joe List" <sound@lists.io.com>
Sent: Saturday, 15 September, 2001 02.15
Subject: Re: [JN] re: Madness on the Joe List
> Oh Bob, don't you just WISH you could suspend the 1st Amendment on people
'like
> me'.
>
> BobC wrote:
>
> > Please stop your bullshit! Things are bad enough already. Go iron your
sheet
> > and find something to sell on Ebay!...
> >
> > ----- Original Message -----
> > From: Steve Van Osdell
> > To: Bill Sadler
> > Cc: Joe Net
> > Sent: Friday, September 14, 2001 10:19 PM
> > Subject: Re: [JN] re: Madness on the Joe List
> >
> > Martin Luther King, Jr??? Didn't I read somewhere about his ties with
> > Communism...or was I 'having a dream'.
>
>
=========================================================================
From: "BobC" <bobcx@nyc.rr.com>
Subject: Re: [JN] re: Madness on the Joe List
Date: Sun, 16 Sep 2001 01:56:09 -0400
Source: Sound Digest Archive v02.n974
Please stop your bullshit! Things are bad enough already. Go iron your sheet
and find something to sell on Ebay!...
- ----- Original Message -----
From: Steve Van Osdell
To: Bill Sadler
Cc: Joe Net
Sent: Friday, September 14, 2001 10:19 PM
Subject: Re: [JN] re: Madness on the Joe List
Martin Luther King, Jr??? Didn't I read somewhere about his ties with
Communism...or was I 'having a dream'.
=========================================================================
From: ToobWiz@aol.com
Subject: Re: [JN]Madness on the Joe List: now a little history
Date: Fri, 14 Sep 2001 17:47:09 EDT
Source: Sound Digest Archive v02.n972
In a message dated 09/14/2001 4:<BR31:<BR58 PM
Eastern Daylight , sadlerb@mweb.co.za writes:> I can't believe some of the
statements being made on the list especially the
> anti-Israel sentiment, all of this born out of a total ignorance of the
> history of the land of Israel, or is it just anti-American and anti-any
body
> who is seen to be friendly with the US.
Bill,
I submit the following to you in the spirit of friendship, not as an attack
upon you or upon Dr. King's memory. Very great men can be in error and even
in ignorance. In this case Dr. King was very definitely in ignorance. But it
is not to his discredit that he was. I will below detail for some historical
information that is very easily verified, though it is not very well known.
The story below can be checked in "The Encyclopaedia of Judaism" and will be
found to be in agreement. I can furnish references for this well-known and
well-regarded reference book if anyone wishes to check on the below, though
it is readily available.
Before giving the historical information, I would like to propose a story by
analogy.
Suppose that you and I and some other acquaintances were to adopt the culture
and religion of the Sioux and engaged in extended practice of it. At some
later date, were we to place a claim upon "our historical homeland" in the
Dakotas or wherever, would you think that claim to be valid or reasonable? I
expect not.
This is exactly the condition that pertains to the Zionists in Israel. There
are many terms which describe various "divisions" within Judeaism, such as
Ashkenazim, Sephardim, and others. Non-Jews aren't generally familiar with
the meanings, and that unfamiliarity gives rise to some serious
misunderstandings of who these peoples are.
Likewise, it is important to understand that the term "anti-Semite" does not
mean "anti-Jew", regardless of how much it has been misused (in many cases
intentionally) to mean that. It means "against Semites" or those of Semitic
blood. Semitic blood is esentially the bloodline of Jacob, renamed by God
"Israel", or more generally, of the bloodline which was named by God in His
covenant promises to the patriarch Abraham. The easily traceable Semitic
peoples today are comprised esentially of the Palestinians and other original
people of the Jordan valley. There are great multitudes of Semitics in the
world who at this time do not know that they have the blood of Abraham, as
the information was "lost" along with the "Lost Tribes of Israel". However,
their location was well known in the time of the writing of the New
Testament, as evidenced by the greeting of the Epistle of james, and by
Jesus' remarks to his disciples in Matthew chapter 10 and other places.
Jeremiah and Isaiah also plainly were aware of the locations from statements
in their writings. The lost tribes are an interesting study, but are
tangential to this posting.
Approximately 1000 years ago in the Khazar kingdom in central Asia, a certain
"Khagan" or tribal ruler, possibly named Bulan, sought a way to keep his
people from being absorbed by either the Rus from above or the Muslims from
the South. To that end, he established Judaeism (lot of the stroy omitted
here) as the "state religion". He required the entire kingdom to convert and
he set up schools and required his leaders to be educated and with them their
families. This Khazar line was of Japethetic blood, not Semitic. They sprung
from Japeth's line before Abraham and his line were covenanted.
Again, shortening the story a great deal, this ruler chose Judeaism for his
nation, after extended instruction by scholars from Christianity, Judeaism,
and Islam. Importantly , for the purposes of this discussion and for his
needs, he chose Babylonian Talmud Judeaism, which was known then to be a
gross corruption of the writings that comprised the Book of the Nation of
Israel, having been modified so as to avoid conflict witht he pagan
Babylonian mystery religion. The value to Bulan, if indeed that was his name,
was this: the Babylonian Talmud contained over 2500 "laws" that permitted
control by a ruler, controls that did not exist in the "Jerusalem Talmud"
(empahsis mine, it was not called that by the Nation of Israel). Further, and
this was the part that answered Bulan's original intent, adherence to this
religion made his people absolutely unassimilable. You will find by
examination, that the principle holds even today. Anyway, these peoples
worked consistently westward toward the centers of civilization and economy
in Europe and they comprised nearly 100% of the Jews who were in Poland and
Eastern Europe at the bennining of this century.
Where were the original Abrahamic Jews? (I think a more important question is
"Where was Israel, the nation?" but, as I said above, that is a different
study.) Well, they were dispersed, but mostly to "Iberia". Ever wonder why
Spain is called in its ancient name "Land of the Hebrews"? Ever wonder why
there is an Ebro River in Spain? Likewise there is a great number of
landmarks in Spain denoting Hebrew.
Now, the above, is first, not in any way anti-Semitic. It is not telling
about a Semitic people, and it is not anti-anyone, being merely a bit of
history that has been rendered arcane to the modern world (though well-known
as late as the Austro-hungarian empire, when it was taught in schools.
Second, it is not in any way "against" the people that we know as Zionists,
again, being merely their acknowledged history.
Assuming that you research the above, you are equipped to first understand
why there might be anti-Sionist sentiments in the world, and more
importantly, I think, be equipped to look at the "Palestinian problem" more
from their side.
I know that I was mystified for years, not understanding why the Jews in the
modern state of Israel were so resented. I feel now that I can view the
situation more even-handedly than before. BTW, another historical note: the
work "Jew" is not synonymous with The Nation of Israel". The Jews were only
those people of the Southern Kingdom of Judea, a minority of the nation of
Israel. All Jews (historical, not Khazar) were Israelite, but not nearly all
Israel was Jewish.
OK, I'll quit. The above is meant in no way to be divisive, but rather to
promote truth and understanding. If we remain ignorant of this history, we
have no hope of unravelling what is happening in this very day. For those of
you who are believers in the Book, we have been warned. Read Rev. 3:9 with
new eyes.
God bless you all/Don Carron
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: [JN] Magazines
Date: Sun, 02 Apr 2000 12:03:51 -0400
Source: Sound Digest Archive v02.n507
I've got duplicates of most issues of Speaker Builder (27 issues) and
Audio Amateur/Audio Electronics (20 issues) from 1996 to present.
Anybody want them? Just $5 for postage, or free to a deserving student.
JL
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: [JN] Re: Magazines
Date: Mon, 03 Apr 2000 09:08:15 -0400
Source: Sound Digest Archive v02.n508
John Levreault wrote:
>
> I've got duplicates of most issues of Speaker Builder (27 issues) and
> Audio Amateur/Audio Electronics (20 issues) from 1996 to present.
> Anybody want them? Just $5 for postage, or free to a deserving student.
>
> JL
Boy, I should have auctioned them! I received 30+ replies, so please
forgive me for not responding individually. They've found a home with a
student.
JL
=========================================================================
From: Timo Christ <carnivor@uni-bremen.de>
Subject: [JN] Magger Math
Date: Mon, 04 Sep 2000 14:32:52 +0200
Source: Sound Digest Archive v02.n653
Hi All,
Bill spotted my weak point; math lazyness.
Ok, i didn't correctly calculate the magger before i built it. Because
of that i ended up with a too weak one which is essentially useless. :-)
Since Bill wouldn't stop bugging me with the math questions, here goes;
The current rise after switch on in the magger can be calculated like
this:
i = (U/R)*(1- exp(-(R/L)*t) )
U = source voltage
R = DC resistance in circuit (coil resistance)
L = inductance of coil
t = time
t = L / R (time constant)
For my present circuit this gives 13.5 A (7 ohm, 150V, 20mH).
As inductance and DC resistance get lower the current gets higher.
Inductance is the important parameter.
The magnetic field strength can be calculated like this:
H = (N*I) / l
N = windings
I = current
l = length of coil
(this formula is simplified and applies to long cylindrical coils only,
versions which factor in short coils can be found).
For me: 75000 A/m
In one of the texts which Bill quoted it was said that 3 kOe = 240000
A/m are required to charge AlNiCo magnets.
Whatever, it looks like i have to wind a new coil to get anywhere (and
will get beefier SCRs to deal with the current).
But i'm not sure if i want to do that right now.
I'll probably built a "final version" of the magger some day with some
more convenient features.
Best Regards,
Timo
- --
/ /--' Timo Christ carnivore@uni-bremen.de
/ /<-. EE Student University of Bremen, Germany
__/ /__/ Horns 'r more fun:
' http://www-user.uni-bremen.de/~carnivor/
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: [JN] Magic Wires
Date: Thu, 23 Sep 1999 17:08:36 -0600 (MDT)
Source: Sound Digest Archive v02.n284
For those who are interested, you can see what happened when John Summer,
bachelor's in physics and doctorate in statistics, became annoyed with Tom
Nousaine's claims that wires don't matter and challenged him to blind
testing of his designs.
http://www.vxm.com/21R.64.html
Doug Purl
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: Re: [JN] Magic Wires
Date: Fri, 24 Sep 1999 13:37:33 -0600 (MDT)
Source: Sound Digest Archive v02.n285
On Fri, 24 Sep 1999, Daniel Normolle wrote:
> Doug Purl wrote:
>
> > For those who are interested, you can see what happened
> > when John Summer, bachelor's in physics and doctorate in
> > statistics, became annoyed with Tom Nousaine's claims
> > that wires don't matter and challenged him to blind
> > testing of his designs.
> >
> > http://www.vxm.com/21R.64.html
> >
> > Doug Purl
>
> Oh, look, honey, it's the troll of the month club!
>
> In defense of my profession, the phrase "doctoral work in
> statistical analysis and research design" generally means
> "didn't finish degree" or "was forced to take a statistics
> course in graduate school." Jack Summer is not a current
> member of the ASA and has no publications in the statistical
> literature back to 1965.
Are you saying the owner of Transparent Audio is engaged in a transparent
ruse? There is gambling here? I'm shocked, Rick, shocked!
Capitaine Louis Renault
=========================================================================
From: Daniel Normolle <monk@umich.edu>
Subject: Re: [JN] Magic Wires
Date: Fri, 24 Sep 1999 14:45:55 -0400
Source: Sound Digest Archive v02.n285
Doug Purl wrote:
> For those who are interested, you can see what happened
> when John Summer, bachelor's in physics and doctorate in
> statistics, became annoyed with Tom Nousaine's claims
> that wires don't matter and challenged him to blind
> testing of his designs.
>
> http://www.vxm.com/21R.64.html
>
> Doug Purl
Oh, look, honey, it's the troll of the month club!
In defense of my profession, the phrase "doctoral work in
statistical analysis and research design" generally means
"didn't finish degree" or "was forced to take a statistics
course in graduate school." Jack Summer is not a current
member of the ASA and has no publications in the statistical
literature back to 1965.
dpn
=========================================================================
From: "STEVE CORNETT" <SCORNETT@usagroup.com>
Subject: Re: [JN] Magic Wires
Date: Mon, 27 Sep 1999 08:48:51 -0500
Source: Sound Digest Archive v02.n286
Doug posted:
"...Are you saying the owner of Transparent Audio is engaged in a transparent
ruse? There is gambling here? I'm shocked, Rick, shocked!
Capitaine Louis Renault"
Shall we now round up the usual suspects?
Signor Ferrari
=========================================================================
From: "David Suess" <david_suess@hotmail.com>
Subject: [JN] Magnavox console amp question
Date: Wed, 19 Sep 2001 11:20:24 -0500
Source: Sound Digest Archive v02.n978
This past weekend I was given an old Magnavox console stereo. Even
though it "worked", i immediately pulled the amp out of the console
and put it into my system.
The topology is a 6eu7 driver with what appears to be 6bq5 PSE output.
I was surprised to find that the thing had a major oscillation problem,
or motorboating. This was at a low frequency. Any ideas? Did I upset
something by getting rid of the connection to the tuner and record
player parts of the system (the power amp provides power for the entire
system). Are my speakers a mis-match for this thing? I tried two
different sets.
Anyway, my ultimate goal is to just use the power xformer, choke,
and output xformers to build soemthing else.
- - david
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] Magnavox console amp question
Date: Wed, 19 Sep 2001 23:52:49 -0400
Source: Sound Digest Archive v02.n979
David Suess wrote:
>
> This past weekend I was given an old Magnavox console stereo. Even
> though it "worked", i immediately pulled the amp out of the console
> and put it into my system.
>
> The topology is a 6eu7 driver with what appears to be 6bq5 PSE output.
>
> I was surprised to find that the thing had a major oscillation problem,
> or motorboating. This was at a low frequency. Any ideas? Did I upset
> something by getting rid of the connection to the tuner and record
> player parts of the system (the power amp provides power for the entire
> system). Are my speakers a mis-match for this thing? I tried two
> different sets.
Some of these console setups are complex and filled with interesting
design shortcuts and tricks. You may have removed/altered the feedback
arrangement when you removed the preamp section from the chain. Some of
these units also had one woofer and a pair of tweeters, and there is
some kind of phase circuitry involved to give the impression of true stereo.
- --
Grover Gardner
groverg@postoffice.att.net
Visit my web site at http://home.att.net/~groverg/homepage.htm
=========================================================================
From: RonSonic <ronsonic@tampabay.rr.com>
Subject: Re: [JN] Magnavox console amp question
Date: Thu, 20 Sep 2001 23:16:42 -0400
Source: Sound Digest Archive v02.n980
On Wed, 19 Sep 2001 11:20:24 -0500, you wrote:
>This past weekend I was given an old Magnavox console stereo. Even
>though it "worked", i immediately pulled the amp out of the console
>and put it into my system.
>
>The topology is a 6eu7 driver with what appears to be 6bq5 PSE output.
>
>I was surprised to find that the thing had a major oscillation problem,
>or motorboating. This was at a low frequency. Any ideas?
I'd be surprised if the caps weren't on their last legs, and the only
thing holding the filtering scheme together was the additional load by
the components you removed.
Ron
=========================================================================
From: John Niven <jn@cypress.com>
Subject: [JN] Magnavox console stereo - advice, please
Date: Wed, 08 Nov 2000 11:11:22 -0800
Source: Sound Digest Archive v02.n725
Well I think I'm now a real Joe!
I was in my local Goodwill store and bought a Magnavox stereo
radio/player in this large console for $79.99. Model #1ST285R. Things go
fast at the store so I had to make an uninformed choice, and went for it
(at least the money goes to charity).
I thought this might be a cheap way into playing with valves. It does
work (makes a noise from the radio) but the tuning is disconnected so
its hard to say how well.
I had the back off, and the radio and preamp parts are in one section
and then there's a separate chassis for power supply/amp. This section
looks interesting. It has 4 tubes marked 1 X 6CA4, 1 X 6EU7, and 2 X
EL84/6EU7.
Also what I guess is two smallish OPT's and a larger supply transformer
(enclosed). I guess this could be used as a separate power amp after a
little cleaning and re-housing.
The speakers (marked Magnavox) are 10" (I think) on the cabinet sides
and 4" forward facing. The 4" have a large series cap. I have no idea if
these drivers are useful compared to modern day drivers, but they might
be worth a try.
The radio section has AM, FM stereo, and AFC. I may be able to use this,
but I'm not really a big radio user (except in my car).
The turntable is an old style changer - I would never use it.
But my problem is that I don't know if this unit has more value
reconditioned back to original state. If I did that, frankly, I would
have no use for it other than to sell (my wife hates it ;-).
Do I have your (collective) permission to brake it up?
Is the power amp going to amount to anything?
Cheers,
John
=========================================================================
From: StepHydro@aol.com
Subject: Re: [JN] Magnavox console stereo - advice, please
Date: Wed, 8 Nov 2000 14:47:44 EST
Source: Sound Digest Archive v02.n725
John,
Sounds as if you have a little SE pentode stereo amp. It should be good for a
couple of watts and might sound surprisingly good. I'd even think of
strapping it triode, as the OPTs aren't large enough to pass the power that
tube can supply as a pentode.
As to the speakers, you'll have to let your eyes and ears guide you. Some
Magnavox drivers were of decent quality. If you have some of those, they will
need a better cab than the console.
As to value, I don't believe these have accumulated any yet :-) Were it mine,
I would burn the wood and toss everything except the amplifier (and tuner if
I thought I could get it going). And, I would certainly save the tubes if I
tossed the tuner. They are likely very good tubes if they aren't used up.
Sounds as if you have a good excuse to build some TQWTs using budget speakers.
Cehers/Carron
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: Re: [JN] Magnavox console stereo - advice, please
Date: Wed, 08 Nov 2000 12:39:37 -0800
Source: Sound Digest Archive v02.n726
John,
Looks like you and i are at about the same place. 1st the Hadcocks, now a
little SE 6BQ5.
>Magnavox stereo
Magnavox=Philips in the rest of the world
>It has 4 tubes marked 1 X 6CA4, 1 X 6EU7, and 2 X EL84/6EU7
I have a little Normende with a similar complement -- 12AX7s thou. It is
destined to become an FM tuner/line stage + a seperate power amp. With the
seperate power amp chassis, yours sounds to be easier to liberate.
>The speakers (marked Magnavox) are 10" (I think) on the cabinet sides
>and 4" forward facing. The 4" have a large series cap. I have no idea if
>these drivers are useful compared to modern day drivers, but they might
>be worth a try.
Try em. They may surprise you -- or they may be s%$#.
>Do I have your (collective) permission to brake it up?
>Is the power amp going to amount to anything?
Go for it. You may be pleasantly surprised -- i was with the quality of my
5-buck amp -- i was pleased when it worked. I was VERY pleased when i
decided that over-all it was more pleasing than the (decent) SS amp i was
using in the lab.
dave
__________________
Transmission Line Speaker Page
http://www.t-linespeakers.org/
new! Chris Bobiak's variation on a Daline
new! Arhus Triode Festival
=========================================================================
From: Dan Marshall <mdaniel7@uswest.net>
Subject: Re: [JN] Magnavox console stereo - advice, please
Date: Wed, 08 Nov 2000 14:16:12 +0000
Source: Sound Digest Archive v02.n726
Hi John
I agree with others comments, don't try to restore it, just snag the
little SE 6BQ5 amp and have some fun with it. Perhaps the tuner, if it
is in a usable configuration and works well. It will sound better than
you think and with a little upgrading, even better. I would use oil
coupling caps though rather than the 716Ps, as these little amps tend to
be a bit sharp and overly-clear sounding on the top end and oil caps
will soften this a bit. Old tube consoles are hard to give away around
here, but the little SE 6BQ5 amps are worth playing with. In fact they
sell of eBay regularly, sometimes for around what you paid for the
unit. You might try triode-stapping one channel and removing the
feedback and compare it with the other channel and see which you like
best. Some 6BQ5 pentode amps with feedback sound quite nice though,
better than you would think. It ought to put out around three watts,
but will likely run out of gas at around a watt at 40 Hz, so you can't
crowd the bass too hard. One thing you ought to give serious
consideration (after you get it all going and are ready to upgrade) is
to use a low level crossover at around 80 Hz and drive an efficient pair
of little satellites with it and use your SS amp to drive a sub. That
way you can use its entire three watts, as the output transformer won't
overload at 80 Hz even at full power. If you have a decent sub, or
something that can pinch hit for a sub, you will be surprised at the
sound quality you will be able to achieve on a beer budget. A decent
pair of bookshelf speakers might work well for subs, assuming they have
good bass response. Little active xovers using op amps are easy to
design and, if the op amps are of decent quality you won't notice any
degradation in the sound quality with this caliber of equipment. Some
of the Magnavox consoles had decent speakers, so they might be worth a
listen. Perhaps if biamped, they would sound good open backed, along
with the little horn tweeters they used to use.
Dan Marshall
John Niven wrote:
>
> Well I think I'm now a real Joe!
>
> I was in my local Goodwill store and bought a Magnavox stereo
> radio/player in this large console for $79.99. Model #1ST285R. Things go
> fast at the store so I had to make an uninformed choice, and went for it
> (at least the money goes to charity).
>
> I thought this might be a cheap way into playing with valves. It does
> work (makes a noise from the radio) but the tuning is disconnected so
> its hard to say how well.
>
> I had the back off, and the radio and preamp parts are in one section
> and then there's a separate chassis for power supply/amp. This section
> looks interesting. It has 4 tubes marked 1 X 6CA4, 1 X 6EU7, and 2 X
> EL84/6EU7.
> Also what I guess is two smallish OPT's and a larger supply transformer
> (enclosed). I guess this could be used as a separate power amp after a
> little cleaning and re-housing.
>
> The speakers (marked Magnavox) are 10" (I think) on the cabinet sides
> and 4" forward facing. The 4" have a large series cap. I have no idea if
> these drivers are useful compared to modern day drivers, but they might
> be worth a try.
>
> The radio section has AM, FM stereo, and AFC. I may be able to use this,
> but I'm not really a big radio user (except in my car).
>
> The turntable is an old style changer - I would never use it.
>
> But my problem is that I don't know if this unit has more value
> reconditioned back to original state. If I did that, frankly, I would
> have no use for it other than to sell (my wife hates it ;-).
>
> Do I have your (collective) permission to brake it up?
> Is the power amp going to amount to anything?
>
> Cheers,
> John
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: RE: [JN] Magnavox console stereo - advice, please
Date: Wed, 08 Nov 2000 15:56:02 -0500
Source: Sound Digest Archive v02.n726
hi john,
i believe i've had one of these, myself.
i got mine on "bulk" [trash] day from the side of the road.
it was a bit of a pain hauling it home in my [then] spider.
i still have the speakers and the amp chassis.
tossed the rest.
in fact, i think i used the OPT in my 1st "darling" 1626 amp.
this was a SE el84 amp, and it sounded pretty good, as is.
welcome to the next level.... ;)
bob.d.
> ----------
> From: John Niven[SMTP:jn@cypress.com]
> Sent: Wednesday, November 08, 2000 2:11 PM
> To: sound@lists.io.com
> Subject: [JN] Magnavox console stereo - advice, please
>
> Well I think I'm now a real Joe!
>
> I was in my local Goodwill store and bought a Magnavox stereo
> radio/player in this large console for $79.99. Model #1ST285R. Things go
> fast at the store so I had to make an uninformed choice, and went for it
> (at least the money goes to charity).
>
> I thought this might be a cheap way into playing with valves. It does
> work (makes a noise from the radio) but the tuning is disconnected so
> its hard to say how well.
>
> I had the back off, and the radio and preamp parts are in one section
> and then there's a separate chassis for power supply/amp. This section
> looks interesting. It has 4 tubes marked 1 X 6CA4, 1 X 6EU7, and 2 X
> EL84/6EU7.
> Also what I guess is two smallish OPT's and a larger supply transformer
> (enclosed). I guess this could be used as a separate power amp after a
> little cleaning and re-housing.
>
> The speakers (marked Magnavox) are 10" (I think) on the cabinet sides
> and 4" forward facing. The 4" have a large series cap. I have no idea if
> these drivers are useful compared to modern day drivers, but they might
> be worth a try.
>
> The radio section has AM, FM stereo, and AFC. I may be able to use this,
> but I'm not really a big radio user (except in my car).
>
> The turntable is an old style changer - I would never use it.
>
> But my problem is that I don't know if this unit has more value
> reconditioned back to original state. If I did that, frankly, I would
> have no use for it other than to sell (my wife hates it ;-).
>
> Do I have your (collective) permission to brake it up?
> Is the power amp going to amount to anything?
>
> Cheers,
> John
>
=========================================================================
From: "Jim Albano" <jimalbano@hotmail.com>
Subject: Re: [JN] Magnavox console stereo - advice, please
Date: Wed, 08 Nov 2000 23:31:56 GMT
Source: Sound Digest Archive v02.n726
Definitely don't junk that little amp. I turned that identical amp--the
unmodified power section--into a sweet little bedroom system that provided
many hours of unmitigated musical pleasure. Unmodified, the bass will flop
around like fish out of water, but that little amp was my first foray into
single-ended sound and after that I was forever hooked. Resist the
temptation to disconnect the feedback loop cuz you won't like the results.
But upgrading the coupling caps was worthwhile, as was replacing the stock
6BQ5's. Sovteks worked very well, but Sylvanias didn't--they sounded great
for a week or so, then mysteriously died (don't ask me why . . . that was
early in my DIY days and I was savvy enough to swap coupling caps but that's
about it). With a good choice of speakers, though, you'll be astounded how
good that little amp will sound. Other than the bass, it totally gets out
of the way. A friend of mine once commented about the sound, "music just,
like, breathes out of this system," and she was right.
>From: John Niven <jn@cypress.com>
>To: sound@lists.io.com
>Subject: [JN] Magnavox console stereo - advice, please
>Date: Wed, 08 Nov 2000 11:11:22 -0800
>
>Well I think I'm now a real Joe!
>
>I was in my local Goodwill store and bought a Magnavox stereo
>radio/player in this large console for $79.99. Model #1ST285R. Things go
>fast at the store so I had to make an uninformed choice, and went for it
>(at least the money goes to charity).
>
>I thought this might be a cheap way into playing with valves. It does
>work (makes a noise from the radio) but the tuning is disconnected so
>its hard to say how well.
>
>I had the back off, and the radio and preamp parts are in one section
>and then there's a separate chassis for power supply/amp. This section
>looks interesting. It has 4 tubes marked 1 X 6CA4, 1 X 6EU7, and 2 X
>EL84/6EU7.
>Also what I guess is two smallish OPT's and a larger supply transformer
>(enclosed). I guess this could be used as a separate power amp after a
>little cleaning and re-housing.
>
>The speakers (marked Magnavox) are 10" (I think) on the cabinet sides
>and 4" forward facing. The 4" have a large series cap. I have no idea if
>these drivers are useful compared to modern day drivers, but they might
>be worth a try.
>
>The radio section has AM, FM stereo, and AFC. I may be able to use this,
>but I'm not really a big radio user (except in my car).
>
>The turntable is an old style changer - I would never use it.
>
>But my problem is that I don't know if this unit has more value
>reconditioned back to original state. If I did that, frankly, I would
>have no use for it other than to sell (my wife hates it ;-).
>
>Do I have your (collective) permission to brake it up?
>Is the power amp going to amount to anything?
>
>Cheers,
> John
_________________________________________________________________________
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=========================================================================
From: "Epstein, Jeremy" <JEpstein@ndbcap.com>
Subject: [JN] Magnavox console stereo - advice, please
Date: Thu, 9 Nov 2000 12:34:06 -0500
Source: Sound Digest Archive v02.n727
bob d. wrote:
>>welcome to the next level.... ;)
Up or down?
- -j
=========================================
Jeremy Epstein........jepstein@ndbcap.com
=========================================
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: RE: [JN] Magnavox console stereo - advice, please
Date: Thu, 09 Nov 2000 12:53:36 -0500
Source: Sound Digest Archive v02.n727
depends upon your point of reference |_
/
> ----------
> From: Epstein, Jeremy[SMTP:JEpstein@ndbcap.com]
> Sent: Thursday, November 09, 2000 12:34 PM
> To: Joenet (E-mail)
> Subject: [JN] Magnavox console stereo - advice, please
>
> bob d. wrote:
>
> >>welcome to the next level.... ;)
>
> Up or down?
>
> -j
> =========================================
> Jeremy Epstein........jepstein@ndbcap.com
> =========================================
>
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Magnavox console stereo - advice, please
Date: Thu, 09 Nov 2000 20:39:04 +0100
Source: Sound Digest Archive v02.n727
John
Take out the SE amp and improve upon that
Keep the speakers, they might sound surprisdingly good !
The rest may be thrown away.....
Guido
=========================================================================
From: John Niven <jn@cypress.com>
Subject: Re: [JN] Magnavox console stereo - advice, please
Date: Thu, 09 Nov 2000 18:51:21 -0800
Source: Sound Digest Archive v02.n728
Thanks for the advice everyone!!!!
Oh dear this could get dangerous! Last night I disconnected the power
amp from the radio and the speakers and reconnected it to some small
bookshelf speakers and my Walkman radio (!).
Well, I sat shivering in my garage (I have a low WAF at the moment), and
listened to the local "smooth jazz" station. Not much happening in the
bass, but I think I just got a glimmer of what I have been reading about
on this list :-)
I definitely want more of this in my system!!!!
I suppose the lack of bass (partly speakers) is mainly due to the OPT's.
I am however thinking that this may well power that midbass up horn on
my drawing board. My current SS amp can handle the lowbass.
A schematic would be nice. Anybody got one? I can draw it out myself,
but its easier to start with something.
I have a pair on Senhisser (SP!!!) headphones that are 400 Ohms. Can I
connect them to the speaker outputs? I always use these as my reference
(in fact in my household I mostly am forced to use them - bloody TV!).
Many more ??? to come!!!
Cheers,
John
- -------------------------------------------------------------------------
John Niven wrote:
>
> Well I think I'm now a real Joe!
>
> I was in my local Goodwill store and bought a Magnavox stereo
> radio/player in this large console for $79.99. Model #1ST285R. Things go
> fast at the store so I had to make an uninformed choice, and went for it
> (at least the money goes to charity).
>
> I thought this might be a cheap way into playing with valves. It does
> work (makes a noise from the radio) but the tuning is disconnected so
> its hard to say how well.
>
> I had the back off, and the radio and preamp parts are in one section
> and then there's a separate chassis for power supply/amp. This section
> looks interesting. It has 4 tubes marked 1 X 6CA4, 1 X 6EU7, and 2 X
> EL84/6EU7.
> Also what I guess is two smallish OPT's and a larger supply transformer
> (enclosed). I guess this could be used as a separate power amp after a
> little cleaning and re-housing.
>
> The speakers (marked Magnavox) are 10" (I think) on the cabinet sides
> and 4" forward facing. The 4" have a large series cap. I have no idea if
> these drivers are useful compared to modern day drivers, but they might
> be worth a try.
>
> The radio section has AM, FM stereo, and AFC. I may be able to use this,
> but I'm not really a big radio user (except in my car).
>
> The turntable is an old style changer - I would never use it.
>
> But my problem is that I don't know if this unit has more value
> reconditioned back to original state. If I did that, frankly, I would
> have no use for it other than to sell (my wife hates it ;-).
>
> Do I have your (collective) permission to brake it up?
> Is the power amp going to amount to anything?
>
> Cheers,
> John
=========================================================================
From: critter <retrovox@bigpond.com>
Subject: Re: [JN] Magnavox console stereo - advice, please
Date: Fri, 10 Nov 2000 11:38:41 +1100
Source: Sound Digest Archive v02.n728
Here in Australia these are referred to as radiograms. ie Radio-gramophone.
Big blond veneer leviathans that still continue to litter the suburbs.
Local brands included Philips, AWA and Kriesler
With 2x 10" speakers and two SE pentode amps, could also be the start of a
guitar amp. Pull the speakers and amp chassis. Ditch the tuner and replace
it with a simple guitar preamp.
critter
=========================================================================
From: "Holger Stein" <steinmusic@cityweb.de>
Subject: [JN] Magnepan SMGa's
Date: Fri, 21 Apr 2000 15:40:21 +0200
Source: Sound Digest Archive v02.n526
- ----- Original Message -----
From: Sellek, Grant (TSA) <Grant.Sellek@transport.sa.gov.au>
To: <sound@deliverator.io.com>
Sent: Friday, April 21, 2000 5:12 AM
Subject: RE: [JN] Progress Report; the TAD 2001 Recovery Project
> >-----Original Message-----
> >From: Paul Butterfield
> >
> >For expediency and consistency, we are LAud measuring raw drivers only,
> >impedance curves only, with the throat pointing up. What, I'm gonna
> >mount, unmount, 16 pound drivers in a horn hundreds of times?
> >Hey, I got nerdgenes, not hunkgenes.... <grin>
>
> What a wimp!!! Log off and go to the gym immediately!
>
> Grant "only bass horns count" Sellek
>
=========================================================================
From: Robert C Chambers <rchamber@norwich.edu>
Subject: [JN] Magnequest FS050-RS500 Differences
Date: Thu, 13 Apr 2000 14:46:39 -0400 (EDT)
Source: Sound Digest Archive v02.n519
Hello-
Is anyone aware of the differences between the older FS050 and newer
RS500 SE output transformers? I think both are 5.0K/80mA primaries.
Thanks,
Robert
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] Magnequest FS050-RS500 Differences
Date: Thu, 13 Apr 2000 22:06:51 -0400
Source: Sound Digest Archive v02.n520
At 2:46 PM -0400 4/13/00, Robert C Chambers wrote:
>Hello-
>
>Is anyone aware of the differences between the older FS050 and newer
>RS500 SE output transformers? I think both are 5.0K/80mA primaries.
>
>Thanks,
>
>Robert
I *think* that the RS series are bobbin-wound as opposed to hand-wound.
- -------
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Patrick Currie <tubesguy@chorus.net>
Subject: [JN] Magnequest (gasp!) iron FS, WTB
Date: Fri, 31 Mar 2000 07:32:03 -0600 (CST)
Source: Sound Digest Archive v02.n505
Now that things have calmed down for several hours, it may be time to do a
little swapmeeting.
I am looking for Magnequest DS-025 or FS-030 outputs, in new or used condition.
I have TFA204 outputs, mounted but unused, for $90 each, plus shipping, and
the _original_ BAC plate chokes, 50H at 80ma, in a larger stack than
current production and with slightly less DCR, for $120 each, in used but
excellent condition, also plus shipping. These are heavy, by the way.
Please email me offlist at: tubesguy@chorus.net
Thanks - Pat
=========================================================================
From: Patrick Currie <tubesguy@chorus.net>
Subject: [JN] Magnequest hookup info?
Date: Tue, 21 Mar 2000 08:02:55 -0600 (CST)
Source: Sound Digest Archive v02.n489
Could anyone help me (and Robert Root) out with the hookup info for the
classic multiple-secondary Magnequest output trannies, ala the FS030 or
DS025? Mikey's offline these days. TIA - Pat
=========================================================================
From: Patrick Currie <tubesguy@chorus.net>
Subject: Re: [JN] Magnequest hookup info?
Date: Tue, 21 Mar 2000 13:54:46 -0600 (CST)
Source: Sound Digest Archive v02.n489
Thanks to all who responded. Got the info - Pat
=========================================================================
From: "Richard Jones" <RJ0101@Sprynet.Com>
Subject: [JN] Magnequest VS Electraprint
Date: Sun, 21 Feb 1999 19:41:46 -0600
Source: Sound Digest Archive v02.n054
This is a multi-part message in MIME format.
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charset="iso-8859-1"
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A quick question:
any comparisons between like a DS-025 and an equivalent electraprint =
tranny?
sound quality??
Thanks
Richard
- ------=_NextPart_000_0006_01BE5DD2.37383B60
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charset="iso-8859-1"
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<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
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<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000 size=3D2>A quick question:</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>any comparisons between like a DS-025 and an =
equivalent=20
electraprint tranny?</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>sound quality??</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Thanks</FONT></DIV>
<DIV><FONT size=3D2>Richard</FONT></DIV></BODY></HTML>
- ------=_NextPart_000_0006_01BE5DD2.37383B60--
=========================================================================
From: Chris Beck <n9zes@execpc.com>
Subject: Re: [JN] Magnequest VS Electraprint
Date: Sun, 21 Feb 1999 20:05:01 -0600
Source: Sound Digest Archive v02.n054
Richard,
This is a very subjective answer to a very subjective question.
Both companies manufacture some very high quality transformers, and to
say which one is better really depends a lot on what circuit you are
using and with what speakers, etc. There have been some fantastic
homebrew and commercial amps built with both brands. It's impossible to
make a blanket recommendation one way or the other.
Personally, I use Electra-Print iron everywhere. In my system, it gives
me a very clean sound that is extended on top and bottom. However,
which ever you choose, I don't think you'll be disappointed. I will
admit to having personal bias towards Electra-Print, being a personal
friend of Jack Elliano, the owner. I am also a happy and satisfied
customer.
ENJOY!
Chris Beck
Richard Jones wrote:
> A quick question: any comparisons between like a DS-025 and an
> equivalent electraprint tranny? sound quality?? ThanksRichard
=========================================================================
From: "Paul Croft" <pcroft@iximd.com>
Subject: RE: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 07:52:36 -0500
Source: Sound Digest Archive v02.n784
Hi Martin,
Whew, I haven't thought about these these in years. The U.S. Our Farce
taught about these when I went through the Automatic Flight Controls tech
school in 1970. I'm pretty fuzzy, but as I recall, these took the small
three-phase signal from a syncro and amplified it to be able to control a
much larger three-phase syncro that actually varied the position of a flight
controls surfaces, such as ailerons and the rudder. I recall these were used
in the B-52 and other bombers that controlled the flight control surfaces
with cables. Most fighters used hydualics to control the flight controls
surfaces.
Whew, what a fuzzy memory. Recalled through a haze of smoke, one might
say... Ah yes, if you can remember the 70s, you didn't have a very good
time! I do recall thinking that if it weren't for vodka in the Warsaw Pact,
Nato would have been in BIG trouble... (Wake up and find yourself in the Air
Force... Ohh NOoooo....)(What a way to dodge the draft!)
Cheers,
Paul
> -----Original Message-----
> From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> Behalf Of Martin Seddon
> Sent: Tuesday, January 16, 2001 7:43 AM
> To: sound@lists.io.com
> Subject: [JN] Magnetic amps
>
>
> Hi,
>
> Anyone know what were 'magnetic amplifiers' used in the early sixties, not
> for audio, but industrial control applications. An aircraft engineer
> friend told me about them but couldnt say the principle.
>
> Martin
>
=========================================================================
From: "Paul Croft" <pcroft@iximd.com>
Subject: RE: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 09:00:44 -0500
Source: Sound Digest Archive v02.n784
Hi Christian,
Actually I don't believe that this is true. I don't recall the technical
details, but the magnetic amps were pretty complex. A transformer will vary
voltage and current inversely while holding power constant. While I really
don't recall the details, I presume that the mag amp actually amplified
current and/or voltage as well as power. The output of the input syncros was
quite small, the syncros being driven were relatively huge. Sorry, no free
lunch here, either!
Cheers,
Paul
> -----Original Message-----
> From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> Behalf Of Christian Rintelen
> Sent: Tuesday, January 16, 2001 8:48 AM
> To: Joelist
> Subject: Re: [JN] Magnetic amps
>
>
> Magnetics = transformer, so who else than Lundahl would build
> magnetic amps ;-)
> Read more about the Lundahl MagAmp here:
> <http://www.hifichoice.co.uk/archive/perl/14_printreview.htm>
>
> Christian
>
=========================================================================
From: "Doug Forbes" <av599@lafn.org>
Subject: Re: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 09:16:06 -0800
Source: Sound Digest Archive v02.n784
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charset="iso-8859-1"
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Magnetic amplifiers are used in servomechanisms for the control of
electromechanical devices. They are also known as direct current
transformers, current transformers, saturable reactors, and amplistats. Such
amplifiers consist of one or more saturable reactors, the controlling
voltage being from a dc source. Magnetic amplifiers can be designed to
deliver almost any amount of power in the 60 to 400 Hz range.
Magnetic amplifiers can also be designed to operate at radio frequencies
however, their frequency range is limited by the transformers and rectifier.
Doug Forbes
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QEEkAjI6j0pa/9k=
- ------=_NextPart_000_007C_01C07F9C.F508E340--
=========================================================================
From: "Remco Stoutjesdijk" <r.m.stoutjesdijk@student.utwente.nl>
Subject: RE: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 14:12:25 +0100
Source: Sound Digest Archive v02.n784
Hi,
> Anyone know what were 'magnetic amplifiers' used in the early
> sixties, not
> for audio, but industrial control applications. An aircraft engineer
> friend told me about them but couldnt say the principle.
A magnetic amplifier modulates a carrier wave through a transformer which is
subsequently filtered to yield the output. It is in fact a form of PWM,
which can be applied to audio when using a supersonic frequency carrier
wave. Some were made for audio with varying results, probably due to the low
Zo, which makes it quite load susceptible. I recall one such amp described
in a German hifi mag about a year and a half ago, don't remember which one
exactly...
The principle is still in use in switched mode PSUs, since the high carrier
frequency allows for smaller transformer cores.
You may want to visit <http://tpub.com/neets/book8/32l.htm> for a more
detailed description.
Regards,
Remco
- --
http://listen.to/rmsaudio
=========================================================================
From: Christian Rintelen <christian@rintelen.ch>
Subject: Re: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 14:48:16 +0100
Source: Sound Digest Archive v02.n784
Magnetics = transformer, so who else than Lundahl would build magnetic amps ;-)
Read more about the Lundahl MagAmp here:
<http://www.hifichoice.co.uk/archive/perl/14_printreview.htm>
Christian
=========================================================================
From: Martin Seddon <mseddon@iinet.net.au>
Subject: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 20:43:14 +0800
Source: Sound Digest Archive v02.n784
Hi,
Anyone know what were 'magnetic amplifiers' used in the early sixties, not
for audio, but industrial control applications. An aircraft engineer
friend told me about them but couldnt say the principle.
Martin
=========================================================================
From: "Paul Croft" <pcroft@iximd.com>
Subject: RE: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 19:18:47 -0500
Source: Sound Digest Archive v02.n785
Hi Remco,
There are those, also. They used to be used in Uninteruptable Power Supplies
and worked by saturating the core of a transformer. They have been replaced
by less expensive technology using solidstate and relays.
However, I don't believe these were what Martin was referring to. He
mentioned that an aircraft engineer mentioned them being used in 1960s era
aircraft.
Cheers,
Paul
> -----Original Message-----
> From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> Behalf Of Remco Stoutjesdijk
> Sent: Tuesday, January 16, 2001 8:12 AM
> To: Joe-Net (E-mail)
> Subject: RE: [JN] Magnetic amps
>
>
> Hi,
>
> > Anyone know what were 'magnetic amplifiers' used in the early
> > sixties, not
> > for audio, but industrial control applications. An aircraft engineer
> > friend told me about them but couldnt say the principle.
>
> A magnetic amplifier modulates a carrier wave through a
> transformer which is
> subsequently filtered to yield the output. It is in fact a form of PWM,
> which can be applied to audio when using a supersonic frequency carrier
> wave. Some were made for audio with varying results, probably due
> to the low
> Zo, which makes it quite load susceptible. I recall one such amp described
> in a German hifi mag about a year and a half ago, don't remember which one
> exactly...
>
> The principle is still in use in switched mode PSUs, since the
> high carrier
> frequency allows for smaller transformer cores.
>
> You may want to visit <http://tpub.com/neets/book8/32l.htm> for a more
> detailed description.
>
> Regards,
> Remco
> --
> http://listen.to/rmsaudio
>
=========================================================================
From: "Paul Croft" <pcroft@iximd.com>
Subject: RE: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 19:39:26 -0500
Source: Sound Digest Archive v02.n785
Hi Doug,
Ah perfect! Not only is your memory better than mine, your schematics are
too!
Thanks for refreshing my memory. What were you smoking back then, Luckys?
Cheers,
Paul
> -----Original Message-----
> From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> Behalf Of Doug Forbes
> Sent: Tuesday, January 16, 2001 12:16 PM
> To: sound@lists.io.com
> Subject: Re: [JN] Magnetic amps
>
>
> Magnetic amplifiers are used in servomechanisms for the control of
> electromechanical devices. They are also known as direct current
> transformers, current transformers, saturable reactors, and
> amplistats. Such
> amplifiers consist of one or more saturable reactors, the controlling
> voltage being from a dc source. Magnetic amplifiers can be designed to
> deliver almost any amount of power in the 60 to 400 Hz range.
> Magnetic amplifiers can also be designed to operate at radio frequencies
> however, their frequency range is limited by the transformers and
> rectifier.
>
> Doug Forbes
>
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: RE: [JN] Magnetic amps
Date: Tue, 16 Jan 2001 23:34:32 -0800
Source: Sound Digest Archive v02.n785
>Secondly, did the old "Carver Cube" amplifiers use mag amp
>technology? I remember they were tiny, with huge power output
>claimed.
I can't remember but they did some tom-foolery with the power supply.
We had one of those thru the shop when they were new. Hooked up an NAD 3020
(as pre), a Carver cube, and a set of Magnepan SMG (cause they present a
fairly non-complex load). Turned it up till we could hear the amp going
into audiable clipping. Then hooked in the power amp section of the 3020.
It played louder (sounded better too). The Carver cube then gained a
derogatory name which is still in use today...
dave
____________________
bartender, bring a pina colada
<riff>
NO. make that a wahter, HtO
=========================================================================
From: "Paul Croft" <pcroft@iximd.com>
Subject: RE: [JN] Magnetic amps
Date: Wed, 17 Jan 2001 04:55:43 -0500
Source: Sound Digest Archive v02.n785
Hi Grant,
I've never heard of a magnetic amp being used in this application. Of
course, potential is often what we can make of it... Go for it! Sometimes
it's the only way to answer our questions.
Cheers,
Paul
> -----Original Message-----
> From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> Behalf Of Sellek, Grant (TSA)
> Sent: Tuesday, January 16, 2001 11:06 PM
> To: 'Paul Croft'; Doug Forbes; sound@lists.io.com
> Subject: RE: [JN] Magnetic amps
>
>
> Is there any potential for making a high power low frequency
> audio magnetic amp for a subwoofer? Say, 200-500W over
> 15-50Hz, with good linearity? Would it be efficient, or
> economical?
>
> Secondly, did the old "Carver Cube" amplifiers use mag amp
> technology? I remember they were tiny, with huge power output
> claimed.
>
> I'm quite interested in any answers to my first question.
>
> Thanks,
> Grant
>
> Grant Sellek, Adelaide, Australia
>
>
> > > -----Original Message-----
> > > From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> > > Behalf Of Doug Forbes
> > > Sent: Tuesday, January 16, 2001
> > >
> > > Magnetic amplifiers are used in servomechanisms for the control of
> > > electromechanical devices. They are also known as direct current
> > > transformers, current transformers, saturable reactors, and
> > > amplistats. Such
> > > amplifiers consist of one or more saturable reactors, the
> > controlling
> > > voltage being from a dc source. Magnetic amplifiers can be
> > designed to
> > > deliver almost any amount of power in the 60 to 400 Hz range.
> > > Magnetic amplifiers can also be designed to operate at
> > radio frequencies
> > > however, their frequency range is limited by the transformers and
> > > rectifier.
>
=========================================================================
From: "Sellek, Grant (TSA)" <Grant.Sellek@transport.sa.gov.au>
Subject: RE: [JN] Magnetic amps
Date: Wed, 17 Jan 2001 14:35:56 +1030
Source: Sound Digest Archive v02.n785
Is there any potential for making a high power low frequency
audio magnetic amp for a subwoofer? Say, 200-500W over
15-50Hz, with good linearity? Would it be efficient, or
economical?
Secondly, did the old "Carver Cube" amplifiers use mag amp
technology? I remember they were tiny, with huge power output
claimed.
I'm quite interested in any answers to my first question.
Thanks,
Grant
Grant Sellek, Adelaide, Australia
> > -----Original Message-----
> > From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> > Behalf Of Doug Forbes
> > Sent: Tuesday, January 16, 2001
> >
> > Magnetic amplifiers are used in servomechanisms for the control of
> > electromechanical devices. They are also known as direct current
> > transformers, current transformers, saturable reactors, and
> > amplistats. Such
> > amplifiers consist of one or more saturable reactors, the
> controlling
> > voltage being from a dc source. Magnetic amplifiers can be
> designed to
> > deliver almost any amount of power in the 60 to 400 Hz range.
> > Magnetic amplifiers can also be designed to operate at
> radio frequencies
> > however, their frequency range is limited by the transformers and
> > rectifier.
=========================================================================
From: Martinburm@aol.com
Subject: Re:[JN] Magnetic amps
Date: Wed, 17 Jan 2001 17:58:06 EST
Source: Sound Digest Archive v02.n785
Hi
Working as a radar technician I learned that magnetic amp can be a motor
running from the mains (or any stable supply) with a dynamo winding on its
axis and a winding for building up a magnetic field to control/power the
dynamo.
Change of the magnetic field driven from a tube servo circuit leads to change
of output current of the "magnetic amp". This indeed can be strong enough to
move a heavy antenna (radar) in a servo circuit.
I think, my car`s generator works on the same principle
Regards Hans-Martin
- -----Original Message-----
>Anyone know what were 'magnetic amplifiers' used in the early sixties, not
>for audio, but industrial control applications. An aircraft engineer
>friend told me about them but couldnt say the principle.
>
>Martin
=========================================================================
From: "Kurt Steffensen" <kurt-steffensen@teliamail.dk>
Subject: Sv: [JN] Magnetic amps
Date: Wed, 17 Jan 2001 18:17:18 +0100
Source: Sound Digest Archive v02.n785
Hi guys.
I just had a minute to spare , and could not help reading this thread.
Magnetic Amplifiers seems to pop up , every now and then.
Actually , M.A. can not be desciped as anything in particual , except that iron is the main issue.
Just like audio amplifiers , can be about everything , except they handles LF freq.
In either words MA is circuits in which the electro mechanical devices are the controlling and ampli
fying parts.
The thing about MA is that you RELY on the iron , and design with this in mind , the active/Voltage
devices being secondary.
I guess that Slagles amps are the closest we come to tubed audio MA's..... ;-)
( But he is very depentent about the merits of the tubes as well , so they can not really be refered
to as MA's )
MA are not Fidelity amps. - They are meant for other purposes. This does however , not imply that th
ey can not
be designed as High Fidelity amps.
MA can cover DC to many 100 kHz !!
( DC is merely an "on/of" issue , not usefull in true signal carriers )
Some years ago , I remember seeing a Swedish Magnetic Audio Amplifier.
It was refered to in positive descritions , by listeners , but it vanished as sudden as it appered o
n the stage..?
MA's can be total complex ( Usually are ) , as the thing the designers looks at is the hysterese cu
rves of the iron etc. They care little about the curves of the transistors/FETS/ Tubes involved , as
they has very little influence of the circuit merits. ( These are used as energy sources , like gas
olin for a motor , nothing else )
BUT.... talk about "skineffect" !!
( A Magnetic amplifier will start play , when the CD is over ;-)
MA also seems to DEPENT on even and odd harmonics in the design process to make the damn things wor
k !!?
Way beyond my understanding...
> > > > Magnetic amplifiers are used in servomechanisms for the control of
> > > > electromechanical devices. They are also known as direct current
> > > > transformers, current transformers, saturable reactors, and
> > > > amplistats.
True , and at the same time I belive , Amplistat is a Brand/Tradename !!
( Imagine if someone owned the term "Class A" :-)
I think I will stick to tube amps , with a little iron here and there...............
WHat says Slagle ??? :-)
- - Kurt
=========================================================================
From: "Chris Vryonides" <chrisvryonides@hotmail.com>
Subject: Re: Sv: [JN] Magnetic amps
Date: Thu, 18 Jan 2001 09:33:18 -0000
Source: Sound Digest Archive v02.n786
Hi,
I seem to recall reading something about David Berning's amps - is their
operating principle similar?
regards
Chris
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
=========================================================================
From: Martin Seddon <mseddon@iinet.net.au>
Subject: RE: [JN] Magnetic amps
Date: Sat, 20 Jan 2001 22:30:55 +0800
Source: Sound Digest Archive v02.n788
Do I understand this correctly (or at all)? At its simplest:
1. Take say a power transformer with two secondaries (primary on mains)
2. Modulate the inductance of the transformer using signal across one of
the secondaries.
3. Rectify the output of the other secondary.
4. Smooth the DC output with filter for chosen bandwidth
5. Feed DC swing thru SE OT to drive 'speaker
ie modulate the power output of the power transformer by swinging its
inductance with the signal.
Now here are the questions - are we not in fact doing this when we impose a
signal back thru the power transformer? (SE power amps) And does low DCR
make the PT more immune to such 'mag amp' effects (if any)?
Martin Seddon
Operations Engineer
Tel. (08) 9348 6266
Fax. (08) 9348 4853
Mobile 0403 053514
=========================================================================
From: Rick Francis <rfrancis@glasscity.net>
Subject: [JN] Magnetic amps -- the UTC story
Date: Thu, 18 Jan 2001 15:25:10 -0500
Source: Sound Digest Archive v02.n786
Joes,
I don't know squat about magnetic amplifiers, but I have this 1954 UTC catalog with a page on them,
including some little application schematics. I scanned it and uploaded it to the PUBLIC folder on t
he XDRIVE (login: joelist password: noise). Actually I uploaded a .gif version and a .jpg version
, both just over 200k, both pretty
clear. Top part of the page is pulse transformers or something, but scroll down and you'll see it.
I also uploaded some time ago the scanned pages for a big Jensen Back-loaded Horn design, about 5 ft
high, 3 ft wide, 2 ft. deep. I will be acquiring a pair of these in the foreseeable future, and wo
uld be interested to hear what anyone knows about them. The pages are also in the PUBLIC folder, an
d the diagrams are pretty clear, esp.
the high-res version.
Rick
=========================================================================
From: dslagle@earthlink.net (dave slagle)
Subject: [JN] magnetic cored speaker X-over inductors
Date: Thu, 6 Jul 2000 18:49:05 -0400
Source: Sound Digest Archive v02.n597
hey,
anybody have any experiences playing around with steel or nickel cored
X-over inductors?
screwed around with them a bit... results thus far look promising.
got one thats 1.5mhy .03 ohms (yes 3/100th of an ohm) and looks linear from
20-20K and will handle 5W at 20hz before saturation....
a comprable goertz will have nearly 10 times the DCR... and the power issue
can be dealt with pretty easily... my next design will be same inductance,
and dcr, but should handle 50W at 20hz...
has anyone ever looked at the capacitences of the air core inductors? the
flat ones in particular look like they would have appreciable capacitence
dave
=========================================================================
From: David Home <DHome@CREO.BE>
Subject: RE: [JN] magnetic cored speaker X-over inductors
Date: Fri, 7 Jul 2000 09:12:03 +0200
Source: Sound Digest Archive v02.n597
Hi Dave. As an aside to your question, my Tannoy Gold crossovers have steel cored inductors. I was a
dvised by both Tannoy technical support and several experienced Tannoy rebuilders that while improve
ments could be made with the caps, switches, etc in the crossover, no current inductor will sound be
tter the stock ones.
My question is why these inductors have a sizable airgap? I mean they don't see any DC or anything..
. Is it for overload protection or something?
Regards, David
-----Original Message-----
From: dslagle@earthlink.net [mailto:dslagle@earthlink.net]
Sent: Friday, July 07, 2000 12:49 AM
To: sound@deliverator.io.com
Subject: [JN] magnetic cored speaker X-over inductors
hey,
anybody have any experiences playing around with steel or nickel cored
X-over inductors?
screwed around with them a bit... results thus far look promising.
got one thats 1.5mhy .03 ohms (yes 3/100th of an ohm) and looks linear from
20-20K and will handle 5W at 20hz before saturation....
a comprable goertz will have nearly 10 times the DCR... and the power issue
can be dealt with pretty easily... my next design will be same inductance,
and dcr, but should handle 50W at 20hz...
has anyone ever looked at the capacitences of the air core inductors? the
flat ones in particular look like they would have appreciable capacitence
dave
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: [JN] magnetic cored speaker X-over inductors
Date: Fri, 07 Jul 2000 08:57:18 -0400
Source: Sound Digest Archive v02.n598
David Home wrote:
>
> Hi Dave. As an aside to your question, my Tannoy Gold crossovers have steel cored inductors. I was
advised by both Tannoy technical support and several experienced Tannoy rebuilders that while impro
vements could be made with the caps, switches, etc in the crossover, no current inductor will sound
better the stock ones.
> My question is why these inductors have a sizable airgap? I mean they don't see any DC or anything
... Is it for overload protection or something?
It flattens out the inductance vs. signal level.
Generally speaking, the inductance of a choke wound on a typical
non-gapped magnetic core will actually increase with increasing signal
level, as much as 2 or 3:1, IIRC. (Actually, it's the perm of the core
that increases.) As a result, the crossover moves around with large
signals.
By gapping the core, this increase in perm is minimized and the perm vs.
signal level flattens out. Of course, you could always design the
ungapped choke so that the perm stays flat up to some predefined power
level.
Decisions, decisions.
JL
=========================================================================
From: dslagle@earthlink.net (dave slagle)
Subject: Re: [JN] magnetic cored speaker X-over inductors
Date: Fri, 7 Jul 2000 10:50:04 -0400
Source: Sound Digest Archive v02.n598
>It flattens out the inductance vs. signal level.
>Generally speaking, the inductance of a choke wound on a typical
>non-gapped magnetic core will actually increase with increasing signal
>level, as much as 2 or 3:1, IIRC. (Actually, it's the perm of the core
>that increases.) As a result, the crossover moves around with large
>signals.
good point... i will also add that it also flattens out the variations in
value with frequency...
in measuring some of my nickel grid chokes the inductance would be all over
the place, and i quickly learned that trying to put an inductance value on
a non-gapped inductor is for the most part pointless, since the value could
be anything depending on the signal you put on it... even if you try to
measure it and spec it around where you will be using it, you are still
measuring it with a static signal, and when you whack it with music. i
suspect that inductance is moving all over theplace. this isn't so
horrible in most cases, since we are generally concerned with having a
minimum amount of inductance to preserve our bass response, so as long as
we vary above that point no harm no foul... and luckily the inductance
generally increases as you drive the choke harder until you reach
saturation so we get away with it...
a speaker x-over inductor is a whole different animal... we are very
concerned that the value remain stable with both signal and frequency, and
air cored inductors are great for this, but you pay for that linearity with
resistance (and capacitence???)
> Of course, you could always design the
>ungapped choke so that the perm stays flat up to some predefined power
>level.
>
>Decisions, decisions.
ok john...any idea on what is at work here...
my approach was to take an iron cored inductor, and gap it enough to remain
linear over the range of voltage/frequency the crossover is concerned with,
and various compromises could be made for the various frequencies/power the
inductor would be used for...
i guess the core material and size is a good place to start... what we want
is the combination of core material, size and gap to give us a very
constant permeability over the range in question... and the higher the net
perm, the lower the dcr you can get
dave
=========================================================================
From: Paul Joppa <pdjoppa@home.com>
Subject: Re: [JN] magnetic cored speaker X-over inductors
Date: Sat, 08 Jul 2000 17:15:11 -0700
Source: Sound Digest Archive v02.n598
David Home asked:
>... As an aside to your question, my Tannoy Gold crossovers have steel cored inductors...
> My question is why these inductors have a sizable airgap? I mean they don't see any DC or
> anything... Is it for overload protection or something?
Without an air gap, an iron cored inductor has an inductance that varies
with signal level and frequency. I recently measured a PA line
transformer whose primary inductance varied between 9.2 henries and 89
henries.
With an air gap the high inductance which occurs at high level or low
frequency) is limited by the low permeability of the gap; if the gap is
big enough then the inductance at most or all signal levels and
frequencies is set by the gap not the iron, and the inductance is
reasonably constant.
For what it's worth, I think the typical SE airgapped transformer still
varies something like 2:1. A really linear crossover inductor would need
to do better than that, so the air gap would have to be bigger relative
to the magnetic path length than in an SE transformer.
I'm sure that now, someone will speculate on SE transformers with large
air gaps. They would be inefficient, having a larger core, and more
leakage inductance/capacitance problems. Nobody seems to make such a
thing, leading me to speculate there may be other reasons they are not
as good as the numbers would lead one to think. The ultimate would be a
air core, i.e. remove the core from an otherwise good transformer and
use it for a tweeter amp. This was discussed here a year or two ago I
think, though I don't remember any resolution or whether anyone has
tried it. It might be a clever way to use surplus PP iron.
- -Paul Joppa
=========================================================================
From: Martin/Campbell family <martincampbell@apex.net.au>
Subject: Re: [JN] magnetic cored speaker X-over inductors
Date: Sun, 09 Jul 2000 10:47:48 +1000
Source: Sound Digest Archive v02.n598
I asked the same question of several people when I was tweaking my Tannoy
Gold crossovers. I came to the same conclusion as below. The cores seem
carefully and deliberately designed to have a gap. JL gives a good clear
explanation of what it is for. The air gap in a core seems like it would be
a good compromise between more wire and resistance but less variable
inductance for an air core vs. less wire and resistance but more variable
inductance for a non-gapped core.
The only thing I considered doing (but havn't done) to the inductors was to
find a more rigid way to clamp them together than the original tape and the
slot in the crossover case. I'd expect that would be a rather minor tweak
compared to the other things I did. To see the other things I did go to
http://users.bigpond.com/tunnelgap/Tannoy/mods.html
Peter Campbell
> David Home wrote:
>>
>> Hi Dave. As an aside to your question, my Tannoy Gold crossovers have steel
>> cored inductors. I was advised by both Tannoy technical support and several
>> experienced Tannoy rebuilders that while improvements could be made with the
>> caps, switches, etc in the crossover, no current inductor will sound better
>> the stock ones.
>> My question is why these inductors have a sizable airgap? I mean they don't
>> see any DC or anything... Is it for overload protection or something?
>
> It flattens out the inductance vs. signal level.
> Generally speaking, the inductance of a choke wound on a typical
> non-gapped magnetic core will actually increase with increasing signal
> level, as much as 2 or 3:1, IIRC. (Actually, it's the perm of the core
> that increases.) As a result, the crossover moves around with large
> signals.
> By gapping the core, this increase in perm is minimized and the perm vs.
> signal level flattens out............
> JL
>
=========================================================================
From: "wmollard" <wmollard@dowco.com>
Subject: [JN] Magnetics and Distortion
Date: Wed, 18 Oct 2000 13:12:49 -0700
Source: Sound Digest Archive v02.n698
Hey Joes,
Well, in for a penny in for a pound. Let me state categorically I am not a
magnetician; I have only read some of their books... and I am up to about an
8% understanding level with lots of distortion!
From what I can gather the A/C imposed across a transformers causes an
induction loop within the hysterisis. In a dc bias transformer this
induction loop is centered at Bdc / Hdc (the dc steady state) within the
material's hysterisis loop. If there is zero dc (parafeed) then the
induction loop is centered at B=0/H=0. The A/C induction loop has it's
endpoints as it intersects the normal rising and falling magnetization
curves of the hysterisis loop. The slope of the line drawn through the
endpoint and midpoint is the incremental permeability (dB/dH). One key, I
think, is the inductance loop takes on different symmetry at different
points; the more unsymmetrical the greater the distortion. The inductance
loop is less symmetrical around the zero dc point (parafeed) because the
hysterisis curve is not symmetrical at this point; though much much better
than at saturation. If we were to look solely at the magnetic of the
parafeed opt we would find a somewhat higher degree of magnetic distortion
than a dc biased transformer... but the parafeed tx is in a circuit and many
other issues (opt size / PS rejection / more inductance due to no gap)
affect an amps performance. Here is a thought... it seems that as the
induction loop approaches the knee of the hysterisis curve where dB/dH is 1,
the least distortion occurs; . Simply put, there is less variation in the
permeability near the knee than at saturation (worse) or zero dc
(parafeed...not bad but not as good as knee). The direct result of any
nonlinear magnetization of the core is waveform distortion. Moreover, I
think it was John L who kindly pointed out that one nasty outcome of
unsymmetrical hysterisis loops is an increase in odd order harmonics... but
this is beyond me; can Mr. Fourier visit me when he is finished with Kurt?
Cheers
Bill
=========================================================================
From: "wmollard" <wmollard@dowco.com>
Subject: [JN] Magnetics and Distortion
Date: Wed, 18 Oct 2000 15:00:54 -0700
Source: Sound Digest Archive v02.n698
Hey Joes,
Well, sometimes I get stuck in a loop and don't see the forest for the
trees...
I kept thinking that the A/C was going to be a stable fixed value; which it
is when you listen to a fixed frequency sine wave. Then the issue of dB/dH
stability within the A/C loop seemed important. But in music... the whole
A/C loop wiggles up and down within the hysteresis loop... so you probable
want to stay in a region where the range of the A/C loop will provide a
reletively stable incremental perm within the hysteresis loop.... parallel
rising / falling magnetization curves. I got some questions into da boss
cause I was gettin carried away thinkin I had it figured out... then reality
set in!
Bill
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: RE: [JN] Magnetics and Distortion
Date: Wed, 18 Oct 2000 18:47:54 -0400
Source: Sound Digest Archive v02.n698
this was one of the points i was trying to emphasize in my last post on the
subject.
subject[parafeed?].
unfortunately i didn't see it come thru to the joe-net.
it seems bill and phil were thinking along the same lines as me.
but we are expressing it in different ways. i think.
i don't want to re-hash my earlier post (i'll resend later if i don't see it
soon)
but bottom line was that i believe the so-called "non-linearity" about the
zero
bias is as phil suggest - a myth.
those who have suggested it may be referring to the "initial magnetization"
that begins from B=0, H=0.
it could be suggested that this is a "one-time-event" and that once your
signal
traverses the loop again and again (ac signal) the trajectory will follow
the normal
B-H curve.
keep in mind that this loop no longer crosses B=0 / H=0, but at B=0 it will
be at
H=+x or H=-x where x is some incremental value.
the slope at these two points is very flat, as far as i can tell.
so aside from the hysteresis, itself. i don't see any increased
non-linearity.
this is pretty-much the same for an SE OPT with dc bias.
except it's origin is displaced by Bdc and Hdc.
but to bill's point. this all holds water for nice symetric sine-waves.
but add harmonics, and more importantly, a large signal dynamic envelope,
and all bets are off.
my question was: do we wind up "re-setting" the core to B=0, H=0 during
"silent" periods, only to go thru the "initial magnitization" trajectory,
again?
and is it really any different in a SE OPT?
bob.d.
> ----------
> From: wmollard[SMTP:wmollard@dowco.com]
> Sent: Wednesday, October 18, 2000 6:00 PM
> To: sound@lists.io.com
> Subject: [JN] Magnetics and Distortion
>
> Hey Joes,
>
> Well, sometimes I get stuck in a loop and don't see the forest for the
> trees...
>
> I kept thinking that the A/C was going to be a stable fixed value; which
> it
> is when you listen to a fixed frequency sine wave. Then the issue of dB/dH
> stability within the A/C loop seemed important. But in music... the whole
> A/C loop wiggles up and down within the hysteresis loop... so you probable
> want to stay in a region where the range of the A/C loop will provide a
> reletively stable incremental perm within the hysteresis loop.... parallel
> rising / falling magnetization curves. I got some questions into da boss
> cause I was gettin carried away thinkin I had it figured out... then
> reality
> set in!
>
> Bill
>
=========================================================================
From: dslagle@earthlink.net (dave slagle)
Subject: Re: [JN] Magnetics and Distortion
Date: Wed, 18 Oct 2000 20:21:32 -0400
Source: Sound Digest Archive v02.n699
>But in music... the whole
>A/C loop wiggles up and down within the hysteresis
>loop... so you probable
>want to stay in a region where the range
>of the A/C loop will provide a
>reletively stable
OK one more time... someone please slam me if i am wrong.. i dare you...
look at:
<http://albums.photopoint.com/j/View?u=37049&a=237580&p=30886175&Sequence=0&
res=high>
this is the bh curves for but gapped 80% nickel and 1X1 interleaved....
the interleave shows a loop and the butt gap shows a line....
so my question is:
why would you bother with a loop when a small gap will give you a line...
ok i know... if i would go to the X10 scale they would show an actual loop
in the "line" (i have those photo's too.. i'll post 'em if someone wants)
let me say... at the 10X scale.. the interleave is a much wider loop as
expected, but the butt gap is still a line... maybe 100X would show a loop,
but it wouls be a small one..... so why interleave and deal with the
loop... work a little harder for your inductance... funny thing is... those
extra turns you have to put on to fight the gap... give you a big boost in
the ac flux arena...
more turns means more hoops to jump through to get acceptable results...
but given the time and patience and $$$ it can be done... as an end user,
you have to expect to pay more...
so i say screw your precious non-linear inductance and gap it and deal with
that hysteresis LINE
dave
=========================================================================
From: "wmollard" <wmollard@dowco.com>
Subject: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 08:19:17 -0700
Source: Sound Digest Archive v02.n700
Hey Dave,
No need to slam you. I am just trying to better understand the issues;
perhaps my 8% comprehension level was a wee bit too optomistic! This
dialogue is a valuable opportunity to discuss/better understand the
theory(s) and, more importantly, develop an understanding where the theory
is lacking. The "try it and discover for yourself" approach is waiting for
my wife to
release her old Sears sewing machine and wool carder to make my new tranny
winder ;>). BTW, what circuit are you using to scope the core loop?
>OK one more time... someone please slam me if i am wrong.. i dare
you...look at:
<http://albums.photopoint.com/j/View?u=37049&a=237580&p=30886175&Sequence=0&
res=high>
A airgap does linearize the hysteresis loop but it introduces other
less desirable entities. An airgap lowers the opts inductance such that your
bottom end becomes soggy.... er the bass does not reproduce as accurately.
The introduction of mo' turns means mo' wire necessitating smaller wire and
increasing the insertion loss caused by A/C heating. The gap itself is
"accomodated" not by the dc bias but rather the A/C signal....
I just checked the Asylum where I left several of these "interesting"
(to me) questions for someone called "mqracing". His informative reply is at
http://www.audioasylum.com/forums/SET/messages/3689.html if you are
interested.
Cheers
Bill
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 11:42:00 -0400
Source: Sound Digest Archive v02.n700
wmollard wrote:
>
> I just checked the Asylum where I left several of these "interesting"
> (to me) questions for someone called "mqracing". His informative reply is at
> http://www.audioasylum.com/forums/SET/messages/3689.html if you are
> interested.
A fine post, too. He seems to know what he's talking about! ;-)
JL
>
> Cheers
> Bill
=========================================================================
From: "wmollard" <wmollard@dowco.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 12:56:10 -0700
Source: Sound Digest Archive v02.n700
Hey T,
You were commenting on...
> >A airgap does linearize the hysteresis loop but it introduces other
> >less desirable entities. An airgap lowers the opts inductance such that
> >your bottom end becomes soggy....
>
> Poppycock. Not with a Transformer correctly designed for the application.
Correct, of course... if you design a transformer differently. However, then
you lose the point I was trying to make that an airgap has an affect on
inductance.
> The Inductance may be low, but at least it is reasonably constant too, not
> all over the place with signal level as it is the place in Transformers
> without Airgap and DC flux in the core.
But there is a large region that the A/C loop can traverse and keep a
constant incremental perm.
> >er the bass does not reproduce as accurately.
>
> My experience is the reverse, based on comparing a SE Parafeed Amplifier
and
> one that is not (admittedly, the Driver Circuits where different too). The
> Parafeed Amp in question (a Kit with a DC coupled Driver and a 2A3) played
> neither as low nore as tight the "normal" SE unit, EL84 Driver RC coupled
to
> a 2A3. And no, the HF performance was also markedly worse, despite the use
> of transformers and chokes designed specifically for parafeed operation.
It
> was the only Parafeed Amp i have heard so far, but it failed to convince
me
> of the merits of the system as being "better" than classic SE.
Well, I guess the observations were either the effect of the driver or the
parafeed; hard to know which though. I must admit to having experimented
only once in this area. The only change was SE airgapped to parafeed/plate
choke. The single change resulted in many effects from different op points
to circuit resonance as you mentioned earlier. The result, without a doubt,
proved one thing for sure... I have not developed a reliable, valid
psychoacoustic memory. Shoulda scoped it!
> >The introduction of mo' turns means mo' wire necessitating smaller wire
>
> Poppycock. It neccitates going up a few core sizes. That is what it does.
Well, correct again. There is a dicotomy between looking and changing one
individual parameter; like "more turns" and looking at the whole... the
whole tranny, the whole system, the whole planet (it isn't so far fetched...
humidity for example). Over time, I think the best approach is a dynamic
balance.
> And I find it very interresting that virtually noone touches on the low
> level performance in this debate, because that where the rabbit lies in
the
> pepper, and a fat and happy bunny it is too.
Har, har, har... that's funny.
> Low level linearity is key, all else is widely neociable as long as the
> human hearing itself is plagued with > 30% THD (and attendant IMD) at 92db
> SPL....
Agreed, I think this is one of the very few design principles that I have
concluded... well at least it looks good today!
Cheers
Bill
> Later T
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 13:48:50 -0600 (MDT)
Source: Sound Digest Archive v02.n700
On Thu, 19 Oct 2000 Frank_Deutschmann@trepp.com wrote:
> As I have now filled my posting quota for the year, I bid you all well;
> I'll leave it as an exercise for capable others to discuss the full
> implications of this wrt low level signals, frequency response, parafeed,
> powersupplies, etc, etc, etc.
The Giant rouses from his aestivation. Not so fast, buddy. There are
still a number of issues hanging fire, such as the identity of a Jutish
former Joe.
Doug Purl
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 14:36:10 -0600 (MDT)
Source: Sound Digest Archive v02.n700
On Thu, 19 Oct 2000, Larry D. Moore wrote:
> I knew it was impossible to go through this whole thing with Jute coming up.
>
> L.D. Moore
A Freudian slip? You do live in Bandon, tax free, don't you Larry? And
you have broken the arms on numerous occasions of several secret agents of
several foreign goverments while you spying in Argentina and inventing the
hemi-head engine and perfecting the shock absorber for Ferrari and
Stirling Moss, no? When you were caught flagrante delictu with their
wives, yes? Don't deny it.
Doug Purl
=========================================================================
From: Frank_Deutschmann@trepp.com
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 15:12:11 -0400
Source: Sound Digest Archive v02.n700
Greetings and Salutations extended to Joes Near and Far!
Thorsten quotes and replies:
>>A airgap does linearize the hysteresis loop but it introduces other
>>less desirable entities. An airgap lowers the opts inductance such that
>>your bottom end becomes soggy....
>Poppycock. Not with a Transformer correctly designed for the application.
>The Inductance may be low, but at least it is reasonably constant too, not
>all over the place with signal level as it is the place in Transformers
>without Airgap and DC flux in the core.
Finally, let there be light in the vacuum!
The issue of THD in transformers is a red herring, nothing but a tease to
the unwary. It is absolutely true that an air gap does not reduce raw THD
when iron cored transformers are placed on "equal footing"; this was well
explained by Partridge. Yet, in a twist somewhat reminiscent of some dude
named "Fermat", after proving this concept, Partridge went on to say that
all iron cored transformers should have an air gap. What gives?!
The answer, I believe, is FM/PM (Frequency Modulation and Phase Modulation)
distortion, or intermod. Without an airgap, the inductance of a
transformer is subject to large variation with low frequency AC; this LF
variation of the inductance (and all related transformer properties)
directly affects simultaneously applied HF AC signal currents and results
in FM/PM/intermod of the higher frequency components of the signal with the
lower frequency components. You will not see this if you simply measure
THD! You *will* see this if you look for it; I have.
By incorporating an airgap into the iron circuit, LF currents are
substantially and significantly decoupled from HF signals, reducing
FM/intermod; the effectiveness of the airgap in this regard improves with
size, and depends on the relative linearity of the magnetic material versus
the linearity of air. Of course, increasing an air gap is subject to other
tradeoffs, some of which have been mentioned here.
I believe that this was all obvious to Partridge, and I believe he felt it
must be obvious to those who would read his papers in depth. As always,
there are two paths to understanding here: top down, from the
engineering/math analysis; and bottom up, from careful experimentation and
thinking. Both are equally valid approaches, but woe be those who take
neither approach here and end up worshiping the false god of THD!
As I have now filled my posting quota for the year, I bid you all well;
I'll leave it as an exercise for capable others to discuss the full
implications of this wrt low level signals, frequency response, parafeed,
powersupplies, etc, etc, etc.
- -frank
=========================================================================
From: "Larry D. Moore" <l-moore@onu.edu>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 16:04:33 -0400
Source: Sound Digest Archive v02.n700
I knew it was impossible to go through this whole thing with Jute coming up.
L.D. Moore
At 01:48 PM 10/19/00 -0600, you wrote:
>On Thu, 19 Oct 2000 Frank_Deutschmann@trepp.com wrote:
>
>> As I have now filled my posting quota for the year, I bid you all well;
>> I'll leave it as an exercise for capable others to discuss the full
>> implications of this wrt low level signals, frequency response, parafeed,
>> powersupplies, etc, etc, etc.
>
>The Giant rouses from his aestivation. Not so fast, buddy. There are
>still a number of issues hanging fire, such as the identity of a Jutish
>former Joe.
>
>Doug Purl
>
>
>
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 17:48:21 GMT
Source: Sound Digest Archive v02.n700
Hi,
>A airgap does linearize the hysteresis loop but it introduces other
>less desirable entities. An airgap lowers the opts inductance such that
>your bottom end becomes soggy....
Poppycock. Not with a Transformer correctly designed for the application.
The Inductance may be low, but at least it is reasonably constant too, not
all over the place with signal level as it is the place in Transformers
without Airgap and DC flux in the core.
>er the bass does not reproduce as accurately.
My experience is the reverse, based on comparing a SE Parafeed Amplifier and
one that is not (admittedly, the Driver Circuits where different too). The
Parafeed Amp in question (a Kit with a DC coupled Driver and a 2A3) played
neither as low nore as tight the "normal" SE unit, EL84 Driver RC coupled to
a 2A3. And no, the HF performance was also markedly worse, despite the use
of transformers and chokes designed specifically for parafeed operation. It
was the only Parafeed Amp i have heard so far, but it failed to convince me
of the merits of the system as being "better" than classic SE.
>The introduction of mo' turns means mo' wire necessitating smaller wire
Poppycock. It neccitates going up a few core sizes. That is what it does.
And I find it very interresting that virtually noone touches on the low
level performance in this debate, because that where the rabbit lies in the
pepper, and a fat and happy bunny it is too.
Low level linearity is key, all else is widely neociable as long as the
human hearing itself is plagued with > 30% THD (and attendant IMD) at 92db
SPL....
Later T
Later T
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
Share information about yourself, create your own public profile at
http://profiles.msn.com.
=========================================================================
From: Christian Rintelen <christian@rintelen.ch>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 18:26:04 +0200
Source: Sound Digest Archive v02.n700
John Levreault wrote:
> wmollard wrote:
> > I just checked the Asylum where I left several of these "interesting"
> > (to me) questions for someone called "mqracing"
>
> A fine post, too. He seems to know what he's talking about! ;-)
Hopefully so - after all, Mike of MagneQuest Racing fame is building (and
selling...) that stuff! ;-)
©
=========================================================================
From: "BobC" <bobcx@bellatlantic.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 17:33:06 -0400
Source: Sound Digest Archive v02.n701
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
> Hi,
>
> Poppycock. Not with a Transformer correctly designed for the application.
T,
Please correct me if I am wrong, but aren't the outputs you are using
designed to be both PP and SE? If so, might this have some affect on you
findings?
thanks
Bob
=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 17:51:12 -0400
Source: Sound Digest Archive v02.n701
Hi T,
Your "experience" reminds me of the joke about the old gentleman in the bar.
He was sitting alone at the end of the bar and had been for some time when
the bartender approached and asked if he would like a drink.
"No", he said, "tried alcohol once - didn't like it."
The bartender thought for a moment and then offered the old gent a cigar.
"No", he said, "tried tobacco once - didn't like it."
The bartender was beginning to become vexed by the obstinate old man. In
desperation, he turned to the old man and asked, "If you don't drink and you
don't smoke, what in blazes are you doing in a bar?"
"Waiting for my son", the old man said.
The bartender rejoined, "Your only child, I presume?"
>
> My experience is the reverse, based on comparing a SE Parafeed Amplifier
and
> one that is not (admittedly, the Driver Circuits where different too). The
> Parafeed Amp in question (a Kit with a DC coupled Driver and a 2A3) played
> neither as low nore as tight the "normal" SE unit, EL84 Driver RC coupled
to
> a 2A3.
Humph! Tried parafeed once - didn't like it, eh?
It would be important here to provide some circuit details. What was the
OPT on the parafeed? How do the driver topologies differ? Too much apples
and oranges to make such absolute statements. Too many folks have the
opposite experience. As I said when I ignited this lingering discussion,
I've heard both series feed and parallel feed in my system - a wide variety
of topologies and valves (no, like you, I haven't been able to A-B amps that
differ only in the output stage configuration).
In that context and with those specific amplifiers, parafeed was better,
although there were a couple of series designs that went toe-to-toe
admirably. Coincidently, these were IT-coupled. This was the verdict of
several ears, including a friend who has taught electronics for a quarter
century and has built the only amp with SS output devices (parafeed) that I
can listen to. How? Bass is deeper, tauter and more natural in its
presentation with no loss of speed. Highs are extended, clear and open.
Overall, there's a greater sense of presence and palpability. Then there's
the improved power supply isolation and the advantages in inductance and
capitance already discussed.
At least two people have changed their systems after hearing parafeed vs
series - one was a gentleman who tri-amplified with series-fed 2A3 amps from
a noted NY avant garde designer and artist. I'm not sayin it's the only
way, unlike some proponents of series-fed topology. It is a very good way
and to my ears the equal or better of well-executed series fed. And, search
as i may through the learned discussions of magnetics here and elsewhere, I
can't find a downside. And spare me the crap about the cap. ;-).
Not trying to hammer you, T. Long-time readers already know you design and
build the best amps on the planet ;-). The rest of us are just competing
for the silver medal (or is that the permalloy medal?).
Best,
Phil
Remember you saw no need for anything but a 300B until you finally heard a
45.
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 18:15:33 -0400
Source: Sound Digest Archive v02.n701
Phil Sieg wrote:
>
> At least two people have changed their systems after hearing parafeed vs
> series
...and at least one didn't. (That would be me.)
JL
=========================================================================
From: "Larry D. Moore" <l-moore@onu.edu>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 18:43:12 -0400
Source: Sound Digest Archive v02.n701
Moore. Larry Moore.
Frankly, the last name is as close as I get to Roger Moore, 007 and spies.
Other than that, my wife has a BMW M roadster that I get to wash once a week.
At 02:36 PM 10/19/00 -0600, you wrote:
>On Thu, 19 Oct 2000, Larry D. Moore wrote:
>
>> I knew it was impossible to go through this whole thing with Jute coming
up.
>>
>> L.D. Moore
>
>A Freudian slip? You do live in Bandon, tax free, don't you Larry? And
>you have broken the arms on numerous occasions of several secret agents of
>several foreign goverments while you spying in Argentina and inventing the
>hemi-head engine and perfecting the shock absorber for Ferrari and
>Stirling Moss, no? When you were caught flagrante delictu with their
>wives, yes? Don't deny it.
>
>Doug Purl
>
>
>
=========================================================================
From: tube@jump.net
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 20:13:27 -0500
Source: Sound Digest Archive v02.n701
Wow! Thanks, this has been driving me crazy for years. "An air-gap does
no good----Therefore, we should use one." Ouch! Okay, at full power
levels, the air-gap does not reduce THD, but it does reduce the phase
modulation caused by the varying inductance. What is most interesting
to me is the fact that examining THD tells you none of this. I have to
say it again, this time backwards. Wow!
Okay, as a possible thank you, here are a couple of interesting core
materials I stumbled across.
http://gammamet.uralinfo.ru/english/docs/gm503b.htm
http://gammamet.uralinfo.ru/english/docs/gm412b.htm
The first one has an initial perm of 40K, and a max perm of 50K! Very,
very linear even without a gap. The second has perms of 35 and 50, a
little less linear, but also very nice. Also, it saturates at 1.23T,
whereas the first material saturates at 0.58T. I have no idea of cost,
availability, etc., but the first, really linear one appears to be
based on Cobalt, alas.
Am I correct in saying that the phase modulation can be reduced by
making the low frequency cutoff very low indeed? Say 0.2Hz or even
less? Obviously this would require fairly low impedance associated
equipment to reduce the Henry count, but it could be done. It may
only be feasible for low level trannies, like microphone or moving
coil step up, but we need those too! The point here is that zero-gap
transformers with 40K permeability can easily have lots of henrys, so
this would not necessarily be difficult.
Finally, I see from Save Slagle's post that my "great idea" for an
easy toroid is old news, as I suspected (it was TOO easy...). Just
make the toroid shaped like a race track with two long straight
sections, machine them so that they have a round cross-section, and
then tape/glue a bobbin around the straight sections, after which it
can be wound just like any other transformer.
The one interesting twist I would like to add to this idea is to use
metal foil, rather than wire, for the reasons spelled out in Allen
Wright's supercable book (basically, foil sounds a lot better). This
would be much easier to do with a high perm core than with a gapped
core, since it would require far fewer turns. I would love to see
this tried with an output trans (really only possible with the really
linear core materials, now that I understand the phase distortion
facts), but for now I would settle for a really top quality MC step
up trans.
Phil
Frank_Deutschmann@trepp.com wrote:
> Greetings and Salutations extended to Joes Near and Far!
>
> Thorsten quotes and replies:
> >>A airgap does linearize the hysteresis loop but it introduces other
> >>less desirable entities. An airgap lowers the opts inductance such that
> >>your bottom end becomes soggy....
>
> >Poppycock. Not with a Transformer correctly designed for the application.
> >The Inductance may be low, but at least it is reasonably constant too, not
> >all over the place with signal level as it is the place in Transformers
> >without Airgap and DC flux in the core.
>
> Finally, let there be light in the vacuum!
>
> The issue of THD in transformers is a red herring, nothing but a tease to
> the unwary. It is absolutely true that an air gap does not reduce raw THD
> when iron cored transformers are placed on "equal footing"; this was well
> explained by Partridge. Yet, in a twist somewhat reminiscent of some dude
> named "Fermat", after proving this concept, Partridge went on to say that
> all iron cored transformers should have an air gap. What gives?!
>
> The answer, I believe, is FM/PM (Frequency Modulation and Phase Modulation)
> distortion, or intermod. Without an airgap, the inductance of a
> transformer is subject to large variation with low frequency AC; this LF
> variation of the inductance (and all related transformer properties)
> directly affects simultaneously applied HF AC signal currents and results
> in FM/PM/intermod of the higher frequency components of the signal with the
> lower frequency components. You will not see this if you simply measure
> THD! You *will* see this if you look for it; I have.
>
> By incorporating an airgap into the iron circuit, LF currents are
> substantially and significantly decoupled from HF signals, reducing
> FM/intermod; the effectiveness of the airgap in this regard improves with
> size, and depends on the relative linearity of the magnetic material versus
> the linearity of air. Of course, increasing an air gap is subject to other
> tradeoffs, some of which have been mentioned here.
>
> I believe that this was all obvious to Partridge, and I believe he felt it
> must be obvious to those who would read his papers in depth. As always,
> there are two paths to understanding here: top down, from the
> engineering/math analysis; and bottom up, from careful experimentation and
> thinking. Both are equally valid approaches, but woe be those who take
> neither approach here and end up worshiping the false god of THD!
>
> As I have now filled my posting quota for the year, I bid you all well;
> I'll leave it as an exercise for capable others to discuss the full
> implications of this wrt low level signals, frequency response, parafeed,
> powersupplies, etc, etc, etc.
>
> -frank
=========================================================================
From: "Dave Slagle" <dslagle@earthlink.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 23:48:07 -0400
Source: Sound Digest Archive v02.n701
> http://gammamet.uralinfo.ru/english/docs/gm503b.htm
>
> http://gammamet.uralinfo.ru/english/docs/gm412b.htm
>
> The first one has an initial perm of 40K, and a max perm of 50K! Very,
> very linear even without a gap. The second has perms of 35 and 50, a
> little less linear, but also very nice. Also, it saturates at 1.23T,
> whereas the first material saturates at 0.58T. I have no idea of cost,
> availability, etc., but the first, really linear one appears to be
> based on Cobalt, alas.
alas is correct... i may be operating on misinformation here but... the
engineer at allied (honeywell) told me that both the square and round loop
anneals of the amorphous materials, was at best a hope, and all we have
today is the as cast anneal... that was a year ago, but the sights you
reference look suspiciously similar to the claims on the honeywell site that
he told me are basically theory... he did note that they have acheived these
results with very small cores, but anything usable in the output realm would
take a huge order to realize...
he did go on to say that the tamura amorphous trannies were cobalt based...
so that makes me wonder... do they indeed have the characteristics of the
site you reference... could we get away with little or no gap with
DC...there seems to be a bit of a conflict here, but so little hard info is
available on these cores.... but one can dream... lets just put our faith in
ploitical correctness and being green... since its the environmental savings
that will bring the amorphous material to our doorstep.
>
> The one interesting twist I would like to add to this idea is to use
> metal foil, rather than wire,
jc mentioned this to me two years ago something crazy about foil
secondaries....at that time i said why? wire is easy to get and does the
same thing.... plus... isn't that how they make capacitors? today... i find
myself wondering where i can get some insulated foil.
dave
=========================================================================
From: tube@jump.net
Subject: Re: [JN] Magnetics and Distortion
Date: Thu, 19 Oct 2000 23:48:15 -0500
Source: Sound Digest Archive v02.n701
Dave Slagle wrote:
> > http://gammamet.uralinfo.ru/english/docs/gm503b.htm
> >
> > http://gammamet.uralinfo.ru/english/docs/gm412b.htm
> >
> > The first one has an initial perm of 40K, and a max perm of 50K! Very,
> > very linear even without a gap. The second has perms of 35 and 50, a
> > little less linear, but also very nice. Also, it saturates at 1.23T,
> > whereas the first material saturates at 0.58T. I have no idea of cost,
> > availability, etc., but the first, really linear one appears to be
> > based on Cobalt, alas.
>
> alas is correct... i may be operating on misinformation here but... the
> engineer at allied (honeywell) told me that both the square and round loop
> anneals of the amorphous materials, was at best a hope, and all we have
> today is the as cast anneal... that was a year ago, but the sights you
> reference look suspiciously similar to the claims on the honeywell site that
> he told me are basically theory... he did note that they have acheived these
> results with very small cores, but anything usable in the output realm would
> take a huge order to realize...
Notice, however, that this is a Russian company, so who knows what they
have or what they can provide. In some areas Russia is technically far ahead
of the West.
Phil
=========================================================================
From: SBench@aol.com
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 00:35:19 EDT
Source: Sound Digest Archive v02.n701
In a message dated 00-10-19 23:50:55 EDT, dslagle@earthlink.net writes:
> jc mentioned this to me two years ago something crazy about foil
> secondaries....at that time i said why? wire is easy to get and does the
> same thing.... plus... isn't that how they make capacitors? today... i
find
> myself wondering where i can get some insulated foil.
>
Interestingly, for relatively low number of turns, e.g., low Z, if you either
paint or use "transformer tape" (the yellow stuff) you can successfully
insulate that copper foil stuff that's available in a number of widths.
I generally get the 2" stuff and cut it to the width needed.
I have used that successfully for switching transformers, but the same
approach can be used for audio transformers as well.
Best Regards,
Steve
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 09:57:44 GMT
Source: Sound Digest Archive v02.n702
Hi,
>Please correct me if I am wrong, but aren't the outputs you are using
>designed to be both PP and SE? If so, might this have some affect on you
>findings?
Well, the Transformer I have in my Amp is an Airgapped unit with the primary
made available in four seperate sections. This allows the use as 9k6 or 2k4
Anode-Anode Push-Pull Transformers and also a range of single ended options.
The unit is designed for around 90mA unbalanced DC in the 9k6 connection. So
it has obviously a huge core.
All this together should make for a Transformer with problems both at LF and
HF when compared to the supposedly superior Parafeed Output system on the
Paraglow. The reverse is true. In addition it is notable that the Amp I use
with that Transformer has massively better detail and resolution without the
graininess and edginess I heard on the Paraglow. Now that may very well be
the Driver on the Paraglow, or the PSU, so I shall not put this per se at
the door of parafeed, but given my doubts about the low level linearity of
Parafeed transformers there may be a hint.
Oh yes, the source used in testing was Vinyl, exclusively.
Later T
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From: "BobC" <bobcx@bellatlantic.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 10:12:15 -0400
Source: Sound Digest Archive v02.n702
From: "T. Loesch" <ezee_e@hotmail.com>
To: <sound@lists.io.com>
Sent: Friday, October 20, 2000 5:57 AM
Subject: Re: [JN] Magnetics and Distortion
T,
One other question... What were the parafeed amps plugged into?
Bob
> Hi,
>
> >Please correct me if I am wrong, but aren't the outputs you are using
> >designed to be both PP and SE? If so, might this have some affect on you
> >findings?
>
> Well, the Transformer I have in my Amp is an Airgapped unit with the
primary
> made available in four seperate sections. This allows the use as 9k6 or
2k4
> Anode-Anode Push-Pull Transformers and also a range of single ended
options.
> The unit is designed for around 90mA unbalanced DC in the 9k6 connection.
So
> it has obviously a huge core.
>
> All this together should make for a Transformer with problems both at LF
and
> HF when compared to the supposedly superior Parafeed Output system on the
> Paraglow. The reverse is true. In addition it is notable that the Amp I
use
> with that Transformer has massively better detail and resolution without
the
> graininess and edginess I heard on the Paraglow. Now that may very well be
> the Driver on the Paraglow, or the PSU, so I shall not put this per se at
> the door of parafeed, but given my doubts about the low level linearity of
> Parafeed transformers there may be a hint.
>
> Oh yes, the source used in testing was Vinyl, exclusively.
>
> Later T
> _________________________________________________________________________
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>
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> http://profiles.msn.com.
>
>
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 10:13:21 GMT
Source: Sound Digest Archive v02.n702
Hi,
>Your "experience" reminds me of the joke about the old gentleman in the
>bar.
Actually Phil your joke is quite off the mark. I have had from the beginning
many concerns about Parafeed which never where allayed. I have experimented
with it a bit, finding not much I liked, but these experiments where made
with "what I had at hand", so I did not allude to them as they might have
been incorrct as the transformers used might have been very suboptimal and
listening was done only by myself.
The Test I did allude to wwas carried with several people present, the
conclusions drawn where unanimous and the Parafeed Amplifier tested is
normally reconed to be a pretty decent one (Paraglow).
So I tried several times and even in something that was designed from the
beginning as Parafeed Amplifier the results failed to convince me any more
than they had done at other occasions.
>It would be important here to provide some circuit details. What was the
>OPT on the parafeed? How do the driver topologies differ? Too much apples
>and oranges to make such absolute statements.
I don't think so. If parafeed had any advantage it should have shown up in
the test easily.
>Too many folks have the opposite experience.
Many folks seem to like a sound I personally cannot stand. In addition, many
Folks only ever use Cd as Source, my tests where carried out with LP as
source, it allows me to hear a lot more what goes on. I often find that what
sounds okay or good on CD shows itself as coloured and problematic on the
purer sourrce provided by Vinyl.
>Not trying to hammer you, T. Long-time readers already know you design and
>build the best amps on the planet ;-).
Not so. I have however in many tests not yet found something that has been
able to exceed the performance I'm getting, short of certain very expensive
japanese products. That is not to say that there ain't any, but I have to
encounter them.
>Remember you saw no need for anything but a 300B until you finally heard a
>45.
Yes, but day to day listening is still back at the 300B, the 45 is too low
in power most of the time.... ;-)
Later T
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=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 10:15:56 -0400
Source: Sound Digest Archive v02.n702
T,
.
>
> I don't think so. If parafeed had any advantage it should have shown up in
> the test easily.
Why? A 300B amp vs a 2A3 amp on 95 dB magnificats? You sure about the
"easily"? BTW, I think the correct way to phrase your interpretaion of the
results of your test is "If parafeed had any advantage IN MY SYSTEM it
should have shown up..."
> Many folks seem to like a sound I personally cannot stand.
Isn't this just a tad condescending? I thought we came to this hobby -
DIY - in order to get away from some self-ordained guru's idea of "absolute
sound". Your implication is that those who attended comparisons at my house
between series and parallel feed and preferred parafeed "like a sound I
personally cannot stand" and are , therefore, wrong.
Again, I think any result is system dependent, which includes the room.
And it holds only for those particular components and group of listeners.
there is no absolute. Well-executed series feed will be poorly executed
parallel feed and vice versa. Parts choice is important in both. You've
gone to great pains to optimize parts choice in your Legacy. Doc has built
to a price point.
The most you can say from your test is that, to your ears, your Legacy amp
is preferrable to Doc's Paraglow. You cannot extend that to ALL parafeed
anymore than I can say that all series feed is inferior to parafeed (and I
may have implied thios in earlier postings for which I apologize).
In addition, many
> Folks only ever use Cd as Source, my tests where carried out with LP as
> source, it allows me to hear a lot more what goes on. I often find that
what
> sounds okay or good on CD shows itself as coloured and problematic on the
> purer sourrce provided by Vinyl.
All listening sessions were done with LP source. You well know I vastly
prefer vinyl and listen to it at least 95% of the time.
>
> >Not trying to hammer you, T. Long-time readers already know you design
and
> >build the best amps on the planet ;-).
>
> Not so. I have however in many tests not yet found something that has been
> able to exceed the performance I'm getting, short of certain very
expensive
> japanese products. That is not to say that there ain't any, but I have to
> encounter them.
Thanks for making my point. ;-)
>
> >Remember you saw no need for anything but a 300B until you finally heard
a
> >45.
>
> Yes, but day to day listening is still back at the 300B, the 45 is too low
> in power most of the time.... ;-)
Sounds like you need a speaker upgrade. ;-)
Phil
>
=========================================================================
From: "BobC" <bobcx@bellatlantic.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 12:08:12 -0400
Source: Sound Digest Archive v02.n702
- ----- Original Message -----
From: "T. Loesch" <ezee_e@hotmail.com>
To: <bobcx@bellatlantic.net>; <sound@lists.io.com>
Sent: Friday, October 20, 2000 11:27 AM
Subject: Re: [JN] Magnetics and Distortion
> Hi there,
>
> >One other question... What were the parafeed amps plugged into?
>
> Into 240V Mains....
>
This is what I was interested in. What power transformer is on the unit? Is
it a 240V or a 120V primary? If it is a 120V how did you step down the
voltage. IIRC Bottlehead does not offer a 240V PT for this unit.
Bob
=========================================================================
From: David Barnett <d_n_b@swbell.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 12:57:08 -0500
Source: Sound Digest Archive v02.n702
On Fri, 20 Oct 2000 00:35:19 -0400 (EDT), SBench@aol.com wrote:
>I have used that successfully for switching transformers, but the same
>approach can be used for audio transformers as well.
If I recall correctly, the transformers in Decca Ribbon tweeters used
a foil secondary.
- --dnb
=========================================================================
From: "BobC" <bobcx@bellatlantic.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 14:07:47 -0400
Source: Sound Digest Archive v02.n702
- ----- Original Message -----
From: "T. Loesch" <ezee_e@hotmail.com>
To: ; <sound@lists.io.com>
Subject: Re: [JN] Magnetics and Distortion
> > "If parafeed had any advantage IN MY SYSTEM it
> >should have shown up..."
T,
Just so we are clear you are condemning a whole approach based on YOUR amp
in YOUR system in YOUR house with all other system parts made by YOU. Is
there a pattern here?
>
> I react VERY adversely to what I percieve as "execcess
> brightness", "agressiveness" and "graininess". Others seem to have no
> problems with sound that I often to be physically painfull at realistic
SPL
> Levels.
Two things here. The amp you listened to does have a SS power supply. Some
folks attribute the comments you make above to SS supplies. Second point.
Since YOU are so sensitive to these artifacts maybe it is time for a hearing
test. You know you are getting a bit older now. :)
> Again, true, yet much of the Sound I have found is in the Iron. Parafeed
> significantly reduces the influence of the PSU (or so it is claimed), the
> whole Amp is optimised around Parafeed with Transformers and chokes
designed
> for that operation mode. Surely it should show that Parafeed offers better
> LF and HF Performance and lower audible Distortion IF PARAFEED DID THESE
> THINGS (which I personally think it doesn't).
IIRC the parafeed iron is minus 1db from well less that 10hz to 45khz. One
can only wonder what you were listening to.
> which BTW where hardly stock to start with but had already been
> substantially improved.
Improved??? Did you hear the amp before these modifications which you call
"improvements" Might this also have something to do with YOUR findings? You
surely were not JUST evaluating parafeed in this instance.
>I still feel that apart from allowing the use of a
> cheaper to make choke and small, high quality OPT
How did you come up with this one. Are you a manufacture now? You have no
idea what is cheaper or more expensive to manufacture. Please be realistic
here.
> Now I will admit that other factors may also have caused this, however I
> would like to know which.... The Paraglow has no coupling Cap to roll off
> LF, a meaty Driver Valve to avoid HF Rolloff and so on. The basic DC
coupled
> Circuit is fine and free from any limiataions on linearity and frequency
> response. Ergo my conclusion that Parafeed is the culprit....
You are taking allot for granted here. It is a mighty big leap to assume
that the parafeed approach is, as you put it the culprit. Please see above.
Bob
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 15:02:09 GMT
Source: Sound Digest Archive v02.n702
Phil,
>Why? A 300B amp vs a 2A3 amp on 95 dB magnificats?
Nope, a 2A3 Amp (as we set up the Legacy for 2A3's and even used the same
pair of KR 2A3's) on speakers that are 102db/2.83V/1m with pink noise
(105db/2.83V/1m with white noise) and a very easy 8 Ohm load.
Very fair and equitable IMHO.
>You sure about the "easily"?
Yup. Absolutely.
>BTW, I think the correct way to phrase your interpretaion of the
>results of your test is "If parafeed had any advantage IN MY SYSTEM it
>should have shown up..."
Okay. But surely in my system it was given as easy a time to prove itself as
possible, extreme wideband speakers (25Hz -6db), easy load, high
sensitivity. Hell, you can't make it any easier and nicer to a Amp....
>Isn't this just a tad condescending?
It is an observation. I react VERY adversely to what I percieve as "execcess
brightness", "agressiveness" and "graininess". Others seem to have no
problems with sound that I often to be physically painfull at realistic SPL
Levels.
>Your implication is that those who attended comparisons at my house
>between series and parallel feed and preferred parafeed "like a sound I
>personally cannot stand" and are , therefore, wrong.
Not so, that is your choice of interpretation. I was commenteing that I have
a somewhat "peculiar" listening preference to put my statements about the
sound into context.
>Again, I think any result is system dependent, which includes the room.
True. In my room you find a pretty well managed LEDE Setup with a very
decent decay time that only at very low frequencies exceeds that recommended
by the IRT for Studio Monitoring.
>Well-executed series feed will be poorly executed parallel feed and vice
>versa. Parts choice is important in both. You've
>gone to great pains to optimize parts choice in your Legacy. Doc has built
>to a price point.
Again, true, yet much of the Sound I have found is in the Iron. Parafeed
significantly reduces the influence of the PSU (or so it is claimed), the
whole Amp is optimised around Parafeed with Transformers and chokes designed
for that operation mode. Surely it should show that Parafeed offers better
LF and HF Performance and lower audible Distortion IF PARAFEED DID THESE
THINGS (which I personally think it doesn't).
>The most you can say from your test is that, to your ears, your Legacy amp
>is preferrable to Doc's Paraglow.
Not only to my ears, but also to those of three other present at the
occasion, including two "neutral" observers and the Owner of the Paraglows,
which BTW where hardly stock to start with but had already been
substantially improved.
>You cannot extend that to ALL parafeed anymore than I can say that all
>series feed is inferior to parafeed (and I may have implied thios in
>earlier postings for which I apologize).
Okay, so in the end it is not at all the principle that matters but the
implementation.... I never said that parafeed could not deliver better sound
than basic Series Feed, especially if the Transformers and chokes are really
very much optimiesed wrt core materials winding and so on.
That is not to say however that if one where to upgrade the Series Feed
Transformers to permalloy or similar materials one may not end up again at
the better position. I still feel that apart from allowing the use of a
cheaper to make choke and small, high quality OPT Parafeeds holds no
advantages sonically that I have been able to percieve.
And as remarked, I see a number of fundamental technical issues in Parafeed
Systems which will IMHO result in exactlt the problems percieved, the
modulated Inductance of the OPT leads to (relatively) poor bass at low
levels, causes IMD Higher up and the hysteresis loop causes low level
grunge, the Anode load choke often has not got a wide enough bandwidth,
leading to (relatively) poor treble. This squares with the impression of
graininess and lacking frequency ange extension I (and all others present)
heard.
Now I will admit that other factors may also have caused this, however I
would like to know which.... The Paraglow has no coupling Cap to roll off
LF, a meaty Driver Valve to avoid HF Rolloff and so on. The basic DC coupled
Circuit is fine and free from any limiataions on linearity and frequency
response. Ergo my conclusion that Parafeed is the culprit....
>Sounds like you need a speaker upgrade. ;-)
Yes, I was thinking of getting a few more Axiom 80's and building a pair of
the 4 X Axiom 80 per side Horns.... This should be at a cool > 110db/W/m
with 16 Ohm impedance.
Later T
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=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 15:09:36 -0400
Source: Sound Digest Archive v02.n702
BobC wrote:
>
> >I still feel that apart from allowing the use of a
> > cheaper to make choke and small, high quality OPT
>
> How did you come up with this one. Are you a manufacture now? You have no
> idea what is cheaper or more expensive to manufacture. Please be realistic
> here.
Well gee Bob, I'm not a housing contractor, but I have a pretty good
idea what makes a house cheaper/more expensive to manufacture. I don't
wind transformers for a living either, but I still know if you want to
use exotic materials like permalloy/nickel/cobalt it's going to cost
more.
Get real Bob!
Peace
- --
Roscoe Primrose
- -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe --
"Once in a while you get shown the light
In the strangest of places if you look at it right." Robert Hunter
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 15:27:13 GMT
Source: Sound Digest Archive v02.n702
Hi there,
>One other question... What were the parafeed amps plugged into?
Into 240V Mains....
Or are you asking "What was the rest of the system"?
The rest was the Oracle MKIII/MKIV (originally a III, most MK IV upgrades
present), with Origin Live Modified Rega RB250 Tonarm (arm also C37
laquered) and with a Goldring Elite MC Cartridge (C37 laquered, including
cantilever).
Step Transformers are some antique Grampian Ribbon Mic Transformers 25 Ohm :
50k, nickelcore, Preamp a copy of the Shindo Laboratories "Claret", with
ECC83 Phonostage and 6072A Linestage, Valve Rectification and passive RC
Filtering for HT and LT.
All Interconnects Cables where my latest generation "Vergeltungswaffe",
super low capacitance shielded units using 0.05 mm enameled OFHC Copper
wires in a pseudo symmetric arrangements with the foil shileds connecting
the chassis of the Units together, dielectric is practically pure air. These
are quite good. The Speakercables are the "UBYTE-2", Copper Foil & Solid
Core, fully symmetrical air dielectric units.
Speakers are the "Magnificat", based around antique Goodmans of England
"Axiom" Series Full Range Drivers with additional supertweeters, covering
overall 25Hz (-6db) to 40kHz (-6db), the upper end is estimated. Sensitivity
is in the > 100db Range (I measured 102db/1m for 2.83V pink noise),
impedance has a minimum of 7.5 Ohm and is notionally 8 Ohm, rather non
reactive in nature due to the DDDLLQD Bass loading. These are very detaield
and delicate sounding speakers with killer dynamics.
The room is quite effectively treated acoustically by sensibly using every
day items as damping and diffuser materials.
I hope that helps, I know it's not what you call Referenz or Studio Grade,
but it's pretty good as it goes.
Later T
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From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 16:13:16 GMT
Source: Sound Digest Archive v02.n702
Bob,
>This is what I was interested in. What power transformer is on the unit?
The one supplied with the Kit.
>Is it a 240V or a 120V primary?
240V Primary.
>If it is a 120V how did you step down the voltage.
No need. to.
>IIRC Bottlehead does not offer a 240V PT for this unit.
To quote from the Bottlehead website:
"Amplifiers
In the past we had been able to supply a universal power transformer for the
amplifier kits. But the supply was too inconsistent, with 6 month waits for
delivery, and our specifications also changed with time so the transformer,
though excellent, was no longer useful to us in every design. We no longer
carry that product, but we hope to have a new 230V primary version of the
MagneQuest power transformer we use available to our customers with 220/240V
AC mains. These are still under development as of late May but we will post
information on the website as soon as they are available for sale."
It seems then that we had Paraglows with these "Universal" Transformers. It
was certainly an original supplied unit, nothing added and no stepdown
transformer used.
Later T
_________________________________________________________________________
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=========================================================================
From: "BobC" <bobcx@bellatlantic.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 16:08:12 -0400
Source: Sound Digest Archive v02.n703
- ----- Original Message -----
From: "Roscoe Primrose" <roscoe@aiko.com>
To: "BobC" <bobcx@bellatlantic.net>
Cc: <sound@lists.io.com>
Sent: Friday, October 20, 2000 3:09 PM
Subject: Re: [JN] Magnetics and Distortion
> BobC wrote:
>
> >
> > >I still feel that apart from allowing the use of a
> > > cheaper to make choke and small, high quality OPT
> >
> > How did you come up with this one. Are you a manufacture now? You have
no
> > idea what is cheaper or more expensive to manufacture. Please be
realistic
> > here.
>
> Well gee Bob, I'm not a housing contractor, but I have a pretty good
> idea what makes a house cheaper/more expensive to manufacture. I don't
> wind transformers for a living either, but I still know if you want to
> use exotic materials like permalloy/nickel/cobalt it's going to cost
> more.
>
> Get real Bob!
Thanks for making my point Roscoe. I am trying to be real. I think you have
something a bit backwards here, possibly because when I snipped what I was
replying to I left out Thorsen reference to parafeed in the beginning of the
sentence. Thorsten is saying JUST because it is parafeed it is cheaper to
manufacture! I was disputing the simple assertion. You are correct exotic
materials, such as the ones often used in parafeed are more expensive. The
combined cost of the choke + trans often exceeds the cost of the SE
airgapped output.
thanks
Bob
=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 17:05:44 -0400
Source: Sound Digest Archive v02.n703
Bob,
The
> combined cost of the choke + trans often exceeds the cost of the SE
> airgapped output.
>
Excellent point. I can't understand the argument that parafeed is cheaper.
Mike's parafeed OPTs cost as much or more than his airgapped trannies. Then
there's the choke. Throwing Tango or Tamura into the mix is rather unfair
given what import costs do to the price. And if either made parafeed
trannies, you can bet the rent that it would cost as much or more as their
airgapped ones.
Actually, with the availability of the likes of the Hammond 125E, etc, it
would seem that cheap series feed is more easily attained than cheap
parafeed.
Phil
=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 17:20:47 -0400
Source: Sound Digest Archive v02.n703
Bob,
>
> Just so we are clear you are condemning a whole approach based on YOUR amp
> in YOUR system in YOUR house with all other system parts made by YOU. Is
> there a pattern here?
Seems to be.
>
> >
> > I react VERY adversely to what I percieve as "execcess
> > brightness", "agressiveness" and "graininess". Others seem to have no
> > problems with sound that I often to be physically painfull at realistic
> SPL
> > Levels.
>
> Two things here. The amp you listened to does have a SS power supply. Some
> folks attribute the comments you make above to SS supplies. Second point.
> Since YOU are so sensitive to these artifacts maybe it is time for a
hearing
> test. You know you are getting a bit older now. :)
My parafeed amps use valve rectification and don't exhibit those qualities.
But I have heard both parafeed and series feed amps that do. ergo, my
conclusion is it's not the particular topology that's at fault, it's the
execution..
The Paraglow is built to a price point. Thorsten has spent long hours and
effort optimizing his amp. It would be like comparing a Volkswagen to a
Morgan. A fairer comparison would be to compare Thorsten's amp to some of
Gordon Rankin's efforts which, while still built to a price point, are built
to the price point of a Mercedes. Or may I humbly suggest my amps, which
also were months in development and spared no cost to find the best
performing parts.
>
>
>
> > Again, true, yet much of the Sound I have found is in the Iron. Parafeed
> > significantly reduces the influence of the PSU (or so it is claimed),
the
> > whole Amp is optimised around Parafeed with Transformers and chokes
> designed
> > for that operation mode. Surely it should show that Parafeed offers
better
> > LF and HF Performance and lower audible Distortion IF PARAFEED DID THESE
> > THINGS (which I personally think it doesn't).
>
> IIRC the parafeed iron is minus 1db from well less that 10hz to 45khz. One
> can only wonder what you were listening to.
Agreed. Mikey's iron is not bandwidth limited. that's one of the pluses of
the approach.
>Ergo my conclusion that Parafeed is the culprit....
>
> You are taking allot for granted here. It is a mighty big leap to assume
> that the parafeed approach is, as you put it the culprit. Please see
above.
Not to raise the spectre of double-blind testing, but if one goes into an
experiment predisposed to an outcome, one tends to skew the experiment that
way. I wouldn't trust myself to set up such a comparison and call it
objective because I am predisposed to favor parafeed. I've done and liked
what it gives and will choose, more often tna not, to design my amps as
parallel fed rather than series fed.
One reason I react rather sharply to the assualts on parafeed is that they
seem to smack of a tad bit of close-mindedness. When i first found the
Joe-Net, I thought i found a bunch of triode nuts on the cutting edge wiling
to try anything and condeming nothing without experiemntation. I would hate
to think that the there is an evolving Joe-Net orthodoxy that closes off
different approaches. Guess I better not mention the parafeed PP45 amps I'm
working on ;-).
Phil
=========================================================================
From: "BobC" <bobcx@bellatlantic.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 18:33:05 -0400
Source: Sound Digest Archive v02.n703
Here is something very interesting posted by Doc Bottlehead on the Audio
Asylum SET Forum in a thread that parallels this one. This helps to explain
Thorsten's unhappiness with the sound of the "modified" parafeed amp.
Things that make you go Hmm...
Bob
**************************************************************
Posted by Doc B. (i) on October 20, 2000 at 13:41:31:
In Reply to: Re: I don't know nothin' 'bout transformers, but... posted by
Thorsten on October 20, 2000 at 02:09:02:
If you would humor me, I'd like to share an interesting anecdote with you
that I think relates to this.
I am aware of the Paraglow amp to which you are referring. Indeed, the
customer was not happy with the sound of the amp either. Unfortunately he
was for some reason reticent to approach us about helping with the problem
upon firstnoticing it, so we did not find out about it for several months
after the completion of the kit. The information regarding the issue is well
documented in the Bottlehead forum archives. There was an issue of noise and
hum that was unacceptable to the customer and he made the effort to send
scope traces of the noise so that we might assist him, a very commendable
approach to troubleshooting the problem that I really appreciated.
Paul Joppa and I had considerable daily communication with the customer to
help him resolve the issue. One thing that became apparent in the course of
this was that the amp was not at all stock, there had been considerable
modifications to the unit in the month between completion and our first
knowledge of the problem. Among these different driver tubes had been
installed, various forms of filtration aside from the circuits we recommend
had been employed at different points, and the basic grounding layout was
not stock. With some thoughtful input from Paul our customer was persuaded
to return the amplifier to its original form as much as possible. Much to my
relief our customer informed me that he is much happier with the performance
of the amps now.
This would all be a moot point, except that I was intrigued to find that the
author of some of the modifications which were removed to return the amp to
its stock configuration and sound was none other than-
Thorsten Loesch
And so we have at least one thing in common, that being we present ideas and
personalities that some people like, and others dislike. And it's not worth
trying to make them like you if they don't, so I'll stop here.
=========================================================================
From: tube@jump.net
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 21:36:39 -0500
Source: Sound Digest Archive v02.n703
Phil Sieg wrote:
> Not to raise the spectre of double-blind testing, but if one goes into an
> experiment predisposed to an outcome, one tends to skew the experiment that
> way. I wouldn't trust myself to set up such a comparison and call it
> objective because I am predisposed to favor parafeed. I've done and liked
> what it gives and will choose, more often tna not, to design my amps as
> parallel fed rather than series fed.
>
> One reason I react rather sharply to the assualts on parafeed is that they
> seem to smack of a tad bit of close-mindedness. When i first found the
> Joe-Net, I thought i found a bunch of triode nuts on the cutting edge wiling
> to try anything and condeming nothing without experiemntation. I would hate
> to think that the there is an evolving Joe-Net orthodoxy that closes off
> different approaches. Guess I better not mention the parafeed PP45 amps I'm
> working on ;-).
>
> Phil
Now wait a second, Phil. There is a big difference between someone
trying something out, then posting his results on this list, from
someone "imposing his orthodoxy" on everyone else. Thorsten tried
parafeed, diligently no doubt, didn't like it, and said so. But that,
my friend, is called DEMOCRACY, and it is a GOOD thing. Nothing can
stifle the flow of new, creative ideas and options faster than stopping
people from stating what they think and have experienced. It is not an
exaggeration to say that this list is one of the most powerful tools on
this planet for advancing the cutting edge of the audio art. What makes
it that way is the ability of people to ACTUALLY SAY what they think
and experience. Take that away by blasting someone as "wrong, wrong,
wrong, because I experienced something different" and you dull that
cutting edge. Shame on you!
Now, that criticism of mine does NOT mean that you should not say why
you think Thorsten is wrong, and there is an excellent example from
this very discussion that backs that up. BobC got info from Doc that
said a buyer was unsatisfied with a paraglow that was modified per
Thorsten's suggestions. Let's assume that Thorsten's mods messed up the
sound of this amp. Thorsten is a VERY knowledgeable, experienced
builder, who no doubt made modifications based on years of experience.
What makes those of us with less experience, building a parafeed amp
from scratch rather than from one of Doc's kits, think that we will not
make the same mistakes??? I hate glare as much as Thorsten, always
have, but now, because of this discussion, if I (finally) make my
parafeed amp and it has lots of glare, I will not simply assume, as
Thorsten and no doubt others have done, that parafeed stinks. I will
assume that either (1) Thorsten messed up and so did I, so I can and
must correct my errors, or (2) Thorsten did not mess up, but parafeed,
like all other topologies, is susceptible to certain errors, neither he
nor I corrected for those errors, and I must do so now.
Thorsten's comments have not dulled my enthusiasm for parafeed at all,
but they have made me aware that if I encounter glare, that I have
either made an error that is easy to make with parafeed, or have failed
to correct an error that often accompanies parafeed. Either way, Doc's
and your comments show that parafeed can indeed be glare free.
In the meantime, trust those of us who have been here for a couple of
years or more that Thorsten is not only NOT one of the bad guys, trying
to impose his will, but that he is in fact one of the biggest
contributors to this list. Please, do not stop this guy from posting! I,
you, and everyone else will be the poorer for it. In your defense, the
lines between criticism, dogma, informative postings, and personal
opinions are all pretty vague, and as readers of this post know, I have
crossed them far more than you ever thought about doing! (Bob remembers,
don't cha? ;-). Now I just hope that THIS post doesn't so much insulting
that it does more harm than good (well, I said it was hard ...)
The other Phil
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Fri, 20 Oct 2000 23:26:47 -0400
Source: Sound Digest Archive v02.n703
At 9:57 AM +0000 10/20/00, T. Loesch wrote:
>
>All this together should make for a Transformer with problems both
>at LF and HF when compared to the supposedly superior Parafeed
>Output system on the Paraglow. The reverse is true. In addition it
>is notable that the Amp I use with that Transformer has massively
>better detail and resolution without the graininess and edginess I
>heard on the Paraglow. Now that may very well be the Driver on the
>Paraglow, or the PSU, so I shall not put this per se at the door of
>parafeed, but given my doubts about the low level linearity of
>Parafeed transformers there may be a hint.
>
I would think the SS constant-current load on the input stage of the
Bottlehead amps would have a far greater impact on the sound than
parafeed. I wonder what would happen if you compared the standard
'Glow with the parafeed version? Perhaps the parafeed version is an
improvement--or not?
- -------
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: RE: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 09:07:42 -0500
Source: Sound Digest Archive v02.n703
More barking dogs.
> Nonetheless, if the discussion turns to parafeed,
> it doesn't take long for the naysayers to surface.
>
> I do not know whether this results from theoretical
> analysis, optimal bench-top experimentation or the
> residual bad taste Doc's presence on the
> list left in some folks' mouths.
OK. That's enough.
Way back when, back when Doc was Dan, the whole
parafeed process was introduced, discussed and
developed right here, on this list.
--Carter
=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 09:20:20 -0400
Source: Sound Digest Archive v02.n703
Phil,
I think you misunderstand my point. I am most emphatically not singling out
Thorsten. He and I have had fruitful exchanges here, on other forums and
privately. From where I sit, it seems that every time the subject of
parafeed comes up on the list, I can count on a core group of individuals to
post theoretical reasons why it is a flawed topology.
I do not know whether this results from theoretical analysis, optimal
bench-top experimentation or the residual bad taste Doc's presence on the
list left in some folks' mouths. Nonetheless, if the discussion turns to
parafeed, it doesn't take long for the naysayers to surface.
Phil
- ----- Original Message -----
From: <tube@jump.net>
Cc: <sound@lists.io.com>
Sent: Friday, 20 October, 2000 22.36
Subject: Re: [JN] Magnetics and Distortion
> Phil Sieg wrote:
>
> > Not to raise the spectre of double-blind testing, but if one goes into
an
> > experiment predisposed to an outcome, one tends to skew the experiment
that
> > way. I wouldn't trust myself to set up such a comparison and call it
> > objective because I am predisposed to favor parafeed. I've done and
liked
> > what it gives and will choose, more often tna not, to design my amps as
> > parallel fed rather than series fed.
> >
> > One reason I react rather sharply to the assualts on parafeed is that
they
> > seem to smack of a tad bit of close-mindedness. When i first found the
> > Joe-Net, I thought i found a bunch of triode nuts on the cutting edge
wiling
> > to try anything and condeming nothing without experiemntation. I would
hate
> > to think that the there is an evolving Joe-Net orthodoxy that closes off
> > different approaches. Guess I better not mention the parafeed PP45 amps
I'm
> > working on ;-).
> >
> > Phil
>
> Now wait a second, Phil. There is a big difference between someone
> trying something out, then posting his results on this list, from
> someone "imposing his orthodoxy" on everyone else. Thorsten tried
> parafeed, diligently no doubt, didn't like it, and said so. But that,
> my friend, is called DEMOCRACY, and it is a GOOD thing. Nothing can
> stifle the flow of new, creative ideas and options faster than stopping
> people from stating what they think and have experienced. It is not an
> exaggeration to say that this list is one of the most powerful tools on
> this planet for advancing the cutting edge of the audio art. What makes
> it that way is the ability of people to ACTUALLY SAY what they think
> and experience. Take that away by blasting someone as "wrong, wrong,
> wrong, because I experienced something different" and you dull that
> cutting edge. Shame on you!
>
> Now, that criticism of mine does NOT mean that you should not say why
> you think Thorsten is wrong, and there is an excellent example from
> this very discussion that backs that up. BobC got info from Doc that
> said a buyer was unsatisfied with a paraglow that was modified per
> Thorsten's suggestions. Let's assume that Thorsten's mods messed up the
> sound of this amp. Thorsten is a VERY knowledgeable, experienced
> builder, who no doubt made modifications based on years of experience.
> What makes those of us with less experience, building a parafeed amp
> from scratch rather than from one of Doc's kits, think that we will not
> make the same mistakes??? I hate glare as much as Thorsten, always
> have, but now, because of this discussion, if I (finally) make my
> parafeed amp and it has lots of glare, I will not simply assume, as
> Thorsten and no doubt others have done, that parafeed stinks. I will
> assume that either (1) Thorsten messed up and so did I, so I can and
> must correct my errors, or (2) Thorsten did not mess up, but parafeed,
> like all other topologies, is susceptible to certain errors, neither he
> nor I corrected for those errors, and I must do so now.
>
> Thorsten's comments have not dulled my enthusiasm for parafeed at all,
> but they have made me aware that if I encounter glare, that I have
> either made an error that is easy to make with parafeed, or have failed
> to correct an error that often accompanies parafeed. Either way, Doc's
> and your comments show that parafeed can indeed be glare free.
>
> In the meantime, trust those of us who have been here for a couple of
> years or more that Thorsten is not only NOT one of the bad guys, trying
> to impose his will, but that he is in fact one of the biggest
> contributors to this list. Please, do not stop this guy from posting! I,
> you, and everyone else will be the poorer for it. In your defense, the
> lines between criticism, dogma, informative postings, and personal
> opinions are all pretty vague, and as readers of this post know, I have
> crossed them far more than you ever thought about doing! (Bob remembers,
> don't cha? ;-). Now I just hope that THIS post doesn't so much insulting
> that it does more harm than good (well, I said it was hard ...)
>
> The other Phil
>
>
=========================================================================
From: "Hugh R. Dean" <aksa1@optushome.com.au>
Subject: Re: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 13:10:09 +1000
Source: Sound Digest Archive v02.n703
Hi Folks,
Phil Seig wrote:
> One reason I react rather sharply to the assualts on parafeed is that they
> seem to smack of a tad bit of close-mindedness. When i first found the
> Joe-Net, I thought i found a bunch of triode nuts on the cutting edge
wiling
> to try anything and condeming nothing without experiemntation. I would
hate
> to think that the there is an evolving Joe-Net orthodoxy that closes off
> different approaches. Guess I better not mention the parafeed PP45 amps
I'm
> working on ;-).
I remember seeing an Atarashi 1971 SE circuit which used parafeed. I've
never heard it, but I think the idea is very cool.
I agree with Phil's sentiment. Let me explain why, because the observation
highlights an important weakness of the human mind.
When we put in long hours discovering a new topology or component synergy,
we think it's ours. We take intellectual ownership. This is our reward for
long, hard, innovative work. It also makes us feel fulfilled, and very
clever.
The problem is, there is no title (let's ignore patents; half the world
certainly does!). So others don't always recognise it. It's like the
stream runs down the bottom of our property; we don't own it, but somehow
we take offense when some other interloper enjoys 'our' spot to fish.
When some guy comes along, notices 'our' work, and heaps derision on it, we
naturally take offense. How would he know? And what right does he have?
And any way, he uses execrable SS, so his opinion can be discounted...
So we are assailed on two fronts; those who actively take on 'our' ideas
and run with them, enjoying 'our' work and refusing to pay hire costs. And
those who deride 'our' ideas because they are outside the square and it
couldn't possibly work anyway.
And there's another problem. Everyone's perception of this take is
different, so ownership and orthodoxy is gradated.
Maybe the answer is:
1. If someone comes up with a great idea, either say nothing, or praise
it, particularly if it is original.
2. Keep an open mind; be prepared to try something different, and don't
deride that which you have not experienced or understood.
Gudonya, Phil. I don't like the narrow, exclusive approach, but we should
be grateful. These folk make us look good!
Cheers,
Hugh
Hugh R. Dean
www.printedelectronics.com
Melbourne, Australia
=========================================================================
From: Christian Rintelen <christian@rintelen.ch>
Subject: Re: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 17:14:08 +0200
Source: Sound Digest Archive v02.n703
Carter Hendricks wrote:
> > I do not know whether this results from theoretical
> > analysis, optimal bench-top experimentation or the
> > residual bad taste Doc's presence on the
> > list left in some folks' mouths.
>
> OK. That's enough.
>
> Way back when, back when Doc was Dan, the whole
> parafeed process was introduced, discussed and
> developed right here, on this list.
Huh?? I remember reading about parafeed first in Langford-Smith before
joining this list some six years ago.... But then again, maybe I'm
wrong... ;-)
Christian
=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 11:21:32 -0400
Source: Sound Digest Archive v02.n704
Funny. I was always taught that good experimentation required carefully
noting methods and materials. This is done in order that others may repeat
said experiment and potentially corroborate the results.
Phil
- ----- Original Message -----
From: "BobC" <bobcx@bellatlantic.net>
To: <sound@lists.io.com>
Sent: Friday, 20 October, 2000 18.33
Subject: Re: [JN] Magnetics and Distortion
> Here is something very interesting posted by Doc Bottlehead on the Audio
> Asylum SET Forum in a thread that parallels this one. This helps to
explain
> Thorsten's unhappiness with the sound of the "modified" parafeed amp.
>
> Things that make you go Hmm...
>
> Bob
>
> **************************************************************
> Posted by Doc B. (i) on October 20, 2000 at 13:41:31:
> In Reply to: Re: I don't know nothin' 'bout transformers, but... posted by
> Thorsten on October 20, 2000 at 02:09:02:
>
>
> If you would humor me, I'd like to share an interesting anecdote with you
> that I think relates to this.
> I am aware of the Paraglow amp to which you are referring. Indeed, the
> customer was not happy with the sound of the amp either. Unfortunately he
> was for some reason reticent to approach us about helping with the problem
> upon firstnoticing it, so we did not find out about it for several months
> after the completion of the kit. The information regarding the issue is
well
> documented in the Bottlehead forum archives. There was an issue of noise
and
> hum that was unacceptable to the customer and he made the effort to send
> scope traces of the noise so that we might assist him, a very commendable
> approach to troubleshooting the problem that I really appreciated.
>
> Paul Joppa and I had considerable daily communication with the customer to
> help him resolve the issue. One thing that became apparent in the course
of
> this was that the amp was not at all stock, there had been considerable
> modifications to the unit in the month between completion and our first
> knowledge of the problem. Among these different driver tubes had been
> installed, various forms of filtration aside from the circuits we
recommend
> had been employed at different points, and the basic grounding layout was
> not stock. With some thoughtful input from Paul our customer was persuaded
> to return the amplifier to its original form as much as possible. Much to
my
> relief our customer informed me that he is much happier with the
performance
> of the amps now.
>
> This would all be a moot point, except that I was intrigued to find that
the
> author of some of the modifications which were removed to return the amp
to
> its stock configuration and sound was none other than-
>
> Thorsten Loesch
>
> And so we have at least one thing in common, that being we present ideas
and
> personalities that some people like, and others dislike. And it's not
worth
> trying to make them like you if they don't, so I'll stop here.
>
>
>
>
>
=========================================================================
From: tube@jump.net
Subject: Re: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 12:31:17 -0500
Source: Sound Digest Archive v02.n704
Phil Sieg wrote:
> Phil,
>
> I think you misunderstand my point. I am most emphatically not singling out
> Thorsten. He and I have had fruitful exchanges here, on other forums and
> privately. From where I sit, it seems that every time the subject of
> parafeed comes up on the list, I can count on a core group of individuals to
> post theoretical reasons why it is a flawed topology.
>
> I do not know whether this results from theoretical analysis, optimal
> bench-top experimentation or the residual bad taste Doc's presence on the
> list left in some folks' mouths. Nonetheless, if the discussion turns to
> parafeed, it doesn't take long for the naysayers to surface.
>
> Phil
That makes sense. Viewing just this one series of exchanges, it looked
like "jumping on one guy for stating his opinion", but I can see how if
an idea gets trashed every time by several guys, it would get very
frustrating.
Overall, I'm glad the discussion came up, because it made me start
thinking about not letting the parafeed trans saturate during turn-on,
watching out for glare, etc. Hopefully you, Thorsten, and the others
will be able to post your thoughts and experiences without too many of
us naysayers giving you too much grief! Funny how delicate and fragile
a forum like this can be sometimes.
Thanks for you posts!
Phil
=========================================================================
From: Robert Jorgensen <robert.jorgensen@advalvas.be>
Subject: Re: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 14:36:18 +0200
Source: Sound Digest Archive v02.n704
Hi Guys,
I'm probably more that usually thick but somehow the connection escapes
me.
Robert
"Larry D. Moore" wrote:
>
> I knew it was impossible to go through this whole thing with Jute coming up.
>
> L.D. Moore
>
> At 01:48 PM 10/19/00 -0600, you wrote:
> >On Thu, 19 Oct 2000 Frank_Deutschmann@trepp.com wrote:
> >
> >> As I have now filled my posting quota for the year, I bid you all well;
> >> I'll leave it as an exercise for capable others to discuss the full
> >> implications of this wrt low level signals, frequency response, parafeed,
> >> powersupplies, etc, etc, etc.
> >
> >The Giant rouses from his aestivation. Not so fast, buddy. There are
> >still a number of issues hanging fire, such as the identity of a Jutish
> >former Joe.
> >
> >Doug Purl
> >
> >
> >
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Sat, 21 Oct 2000 22:24:41 -0500
Source: Sound Digest Archive v02.n704
I wrote about how parafeed had been first
introduced here on the Joe List a long time
ago. I have saved messages from 1997
covering these same issues, but I think it
started earlier than that. But Christian
corrected me:
> Huh?? I remember reading about parafeed first
> in Langford-Smith before joining this list some
> six years ago....
Of course. After a very short search I found some
parafeed schematics from 1932!
--Carter
=========================================================================
From: Patrick Currie <tubesguy@chorus.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Sun, 22 Oct 2000 14:25:54 -0500 (CDT)
Source: Sound Digest Archive v02.n704
One of the Phils said:
>it looked like "jumping on one guy for stating his opinion", but I can see
>how >if an idea gets trashed every time by several guys, it would get very
>frustrating.
>
>Overall, I'm glad the discussion came up, because it made me start
>thinking about not letting the parafeed trans saturate during turn-on,
>watching out for glare, etc. Hopefully you, Thorsten, and the others
>will be able to post your thoughts and experiences without too many of
>us naysayers giving you too much grief! Funny how delicate and fragile
>a forum like this can be sometimes.
>
>Thanks for you posts!
>Phil
Aargh! There aren't any "naysayers." There are, here and on other forums
(fora? Doug, help me here) people who, having discovered something that
works for them, are determined to proselytize, to bring the word to the
great unwashed masses. If others question them on their assertions that
this thing is the greatest thing since sliced bread, they can't just say
"okay, maybe it's not for you." Those people who question aren't just
naysayers, especially if they've tried it and didn't like it, for whatever
reason.
With regard to Doc, he left the list because of one or two people who were
upset that anyone with a commercial interest might have the temerity to
post on subjects that might be of interest to the majority of the list.
Those folks made it a pain for him to be here. He left, end of story. I
don't think his leaving left a bad taste in anybody's mouth, and that, for
God's sake, is not the reason that some thoughtful, rational people don't
like parafeed.
End of screed. From someone who has built para- and series-feed SE amps,
and will probably build at least one more of each in his lifetime. ;-) -
Pat
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 09:13:17 GMT
Source: Sound Digest Archive v02.n704
Hi,
>Just so we are clear you are condemning a whole approach
I'm not condemning it. All I'm doing is to say that IMHO Parafeed ist not
any better than correctly implemented conventional approaches, that is
hardly condemnation.... I'm not saying that Parafeed is inherently bad or
anything, it is just another way of doing things. What I'm objecting to is
the claim by some that parafeed is the end it all and "the only true way".
It ain't.
>based on YOUR amp
Well it was my Amp, yes, but it is one that has seen plenty of comparison to
both commercial and DIY Amplifers of various design and quality.
>in YOUR system in YOUR house with all other system parts made by YOU.
Well, I did not make the turntable.... For the rest, yes, I made the rest of
the system, but again, it is one that must be exceedingly "compatible" as it
also a review system.
>Is there a pattern here?
Perhaps. But again, I was not the only one who heard the same things.
>Two things here. The amp you listened to does have a SS power supply. >Some
>folks attribute the comments you make above to SS supplies.
Isn't parafeed supposed to significantly the PSU sonic Impact? I have
repeatedly seen such claims and it could be even substantiated by the
operating principle to be so.
>Since YOU are so sensitive to these artifacts maybe it is time for a
>hearing test. You know you are getting a bit older now. :)
Well, last time I tested my hearing I found that I had a deep notch around
15k, but could hear 18k and faintly 20k. Sensitivity was around "average".
But yes, my HF Hearing was allways rather better than average and still is.
And yes, this might explain why excessively bright sound is unpleasant to
me.
>Improved??? Did you hear the amp before these modifications which you call
>"improvements"
I did not. The Modifications where carried out by the owner and are mostly
those suggested for the Paraglow by John Camille plus a better (and larger
value) parafeed capacitor.
Later T
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=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 09:36:24 GMT
Source: Sound Digest Archive v02.n704
Hi all,
>Thorsten is saying JUST because it is parafeed it is cheaper to
>manufacture!
You are taking things deliberatly out of context and IMHO are deliberatly
misinterpreting me. I was trying to point out that if Excotix core materials
(and possibly wire) is used, then it is significantly cheaper to make a
Parafeed Transformer and Choke than it is/would be to make such transformers
for normal (DC Offset) SE use. Then again, parafeed really also pretty much
DEMANDS the use of such materials to overcome soem of the problems from the
lack of Airgap and DC Magnetisation.
Anyway, more than enough of that already.
I repeat what I said at the beginning, namely that I cannot see ANY
theortical advantages of Parafeed over classic SE, assuming both are
competently executed and I repeat that my experiments and experiences
(arguably somewhat limited) have failed to substantiate in practice the
often raised claims for ABSOLUTE superiority of Parafeed over classic SE.
And for me that is the end of it.
Later T
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=========================================================================
From: David Home <David_Home@creoscitex.com>
Subject: RE: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 09:55:28 +0200
Source: Sound Digest Archive v02.n704
Excellent point Grover. I am exploring this myself right now. My amps now use a CCS load on the driv
er. I have ordered chokes to replace them. I am not necessarily unhappy with my amps, I just haven't
changed them in almost a year. You understand the motive I am sure! 8^)
Regards, David
- -----Original Message-----
From: Grover Gardner [mailto:groverg@postoffice.att.net]
Sent: Saturday, October 21, 2000 5:27 AM
To: T. Loesch; bobcx@bellatlantic.net; sound@lists.io.com
Subject: Re: [JN] Magnetics and Distortion
At 9:57 AM +0000 10/20/00, T. Loesch wrote:
>
>All this together should make for a Transformer with problems both
>at LF and HF when compared to the supposedly superior Parafeed
>Output system on the Paraglow. The reverse is true. In addition it
>is notable that the Amp I use with that Transformer has massively
>better detail and resolution without the graininess and edginess I
>heard on the Paraglow. Now that may very well be the Driver on the
>Paraglow, or the PSU, so I shall not put this per se at the door of
>parafeed, but given my doubts about the low level linearity of
>Parafeed transformers there may be a hint.
>
I would think the SS constant-current load on the input stage of the
Bottlehead amps would have a far greater impact on the sound than
parafeed. I wonder what would happen if you compared the standard
'Glow with the parafeed version? Perhaps the parafeed version is an
improvement--or not?
- -------
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: tube@jump.net
Subject: Re: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 09:43:17 -0500
Source: Sound Digest Archive v02.n705
Phil Sieg wrote:
> Thorsten,
>
> Enough of the disingenuous attempts to defend your dishonesty.
Okay, I see the light now, I'm out of this one.
Phil
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 09:50:31 -0400
Source: Sound Digest Archive v02.n705
Phil Sieg wrote:
>
>
> Excellent point. I can't understand the argument that parafeed is cheaper.
> Mike's parafeed OPTs cost as much or more than his airgapped trannies. Then
> there's the choke. Throwing Tango or Tamura into the mix is rather unfair
> given what import costs do to the price. And if either made parafeed
> trannies, you can bet the rent that it would cost as much or more as their
> airgapped ones.
You have to remember where parafeed came from. Go back, what, 3 or 4
years? Schmalle et al were inspired to give this parafeed thing a go,
likely prompted to some extent by proddings from Mikey, who sensed some
technical validity to the technique. The early adopters used cheap power
supply chokes, cuz that's all there was. They used
dumpster-diver-special PP output trannies pulled from obscure amps,
along with coupling caps, usually oilers, that they had been pulled from
defunct air conditioners. But you know what? They made music. No, it
wasn't of the same level as bona fide Tango/Tamura/MQ output iron, but
it was a major step forward from SS and modified Stereo 70's. It gave a
lot of people their first exposure to SE, too, and opened up a
horizontal market to those who couldn't afford the high-priced stuff.
This allowed Mikey to develop his extensive parafeed portfolio. For many
people, like owners of the original SEX amp, parafeed has been an
evolutionary path. Sure it would be expensive to do a from-scratch
parafeed using premium plate chokes, nickel trannies, and trick caps,
but for many it's just a process of starting with that SEX amp,
upgrading the choke a couple of years later, then get the tranny for a
Christmas present, etc.
The roots of parafeed are far more humble that for "real" SE. Not
everyone can afford an FS030 and WE300B's as his/her first foray into
SE. Sure it's gotten expensive to do a from-scratch parafeed, but the
performance is in no way inferior to series-fed SE, only different.
JL
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 10:24:24 GMT
Source: Sound Digest Archive v02.n705
Hi all,
>BobC got info from Doc that said a buyer was unsatisfied with a paraglow
>that was modified per Thorsten's suggestions.
Yes, so I noted. And interrestingly all the implemented Mods came from
Material that was at one point in time or the other in Valve or on the
Bottlehead site (especially from John Camilles Notes on improving/modifying
the Paraglow) which I pointed out (and drew out) for Neil.
>I hate glare as much as Thorsten, always have, but now, because of this
>discussion, if I (finally) make my parafeed amp and it has lots of glare, I
>will not simply assume, as Thorsten and no doubt others have done, that
>parafeed stinks.
I have never said that "parafeed stinks". I did mention that I heard some
sonic problems. I did mention that I do not feel that parafeed offers s
great or indeed any advantage over the classic scheme. I did not say that it
did not work, I did not say that I was massively inferior, but that it had
problems just like any approach and needed to be seen in the context of
these. Parafeed is quite valid, but just as in any System the combination is
one that needs to be gotten right, now in three places instead of one and so
on.
I also initially avoided being specific about the Amplifier tested as I
wanted to avoid soning like I publically criticised Doc's Design. I have
noticed that saying as much as "I didn't like the way it sounds" allways
seems to bring out a lot of people (not Doc himself, he's way cool about it)
who seem to feel having to defend the stuff and to point out how great it is
and all.... I must note that it is a jolly decent Amplifier for the money
and all. It is not an Amplifier I'd be happy to live with, but that is
another story.
Other tests I did included attempting Parafeed using another well known
Brand of Output Transformer (which to avoid more discussions about why I
seem to criticise everything) added in parafeed mode to my Amplifers,
reatining the original OPT as Choke. This sounded considerably worse than
the Paraglow did when it was around. The OPT used was a PP-Unit, M6
laminations and the original unit used as choke is airgapped, M6. Coupling
Capacitor was 22uF Ansar Supersound.
Tests in Preamp Outputs again showed that an airgapped SE Preamp OPT when
converted to parafeed sounded considerably worse. on the other hand, using a
Studio Lineoutput Transformer in the same position (this had a large amount
of "better core laminations" (eg. Nickel, Permally, Mu-Metal) in it sounded
as good as the SE Preamp Output in it's native operation mode. Again, I save
myself more hassle by not mentioning any brands here.
Later T
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=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 10:33:19 -0400
Source: Sound Digest Archive v02.n705
Thorsten,
Enough of the disingenuous attempts to defend your dishonesty.
> Yes, so I noted. And interrestingly all the implemented Mods came from
> Material that was at one point in time or the other in Valve or on the
> Bottlehead site (especially from John Camilles Notes on
improving/modifying
> the Paraglow) which I pointed out (and drew out) for Neil.
I have all the VALVEs ever printed. John Camille never authored ANY
articles on upgrading or modifying the Paraglow. Those articles all
concerend the Afterglow, Doc's NON- PARAFEED 2A3 offering. Quite a
differnet beast. Series -fed and all that.
>
> I have never said that "parafeed stinks". I did mention that I heard some
> sonic problems. I did mention that I do not feel that parafeed offers s
> great or indeed any advantage over the classic scheme.
Possibly not in so many words, but it was certainly implied and not subtly.
What you did was rather ineptly implement mods not designed for the specific
amp, plus other changes from your vast storehouse of "The right way to do
things" and it turned out poorly. So your Legacy amp wins again.
Might not some of the desire to trash parafeed come from the fact that Doc
requested to stop calling your amp "the best" (w/o corroboration) on a forum
that he pays for?
.
>
> I also initially avoided being specific about the Amplifier tested as I
> wanted to avoid soning like I publically criticised Doc's Design.
Wise that, since lawyers need work, too.
I have
> noticed that saying as much as "I didn't like the way it sounds" allways
> seems to bring out a lot of people (not Doc himself, he's way cool about
it)
> who seem to feel having to defend the stuff and to point out how great it
is
> and all.... I must note that it is a jolly decent Amplifier for the money
> and all.
Uh, T, until BobC posted Doc's SET asylum reply, you were trashing the amp
with all the vigor you could muster. You questioned the taste and hearing
acuity of people who has liked the Paraglow's sound. You proffered not a
few theoretical reasons parafeed was inferior, despite Mikey pointing out to
you and others the flaws in those arguments on the SET Asylum.
Doc's way cool about it, as you say, because he's in business to sell amps.
Angry and irrational response on public forums would not serve the greater
good of Bottlehead Corp, and he's bright enough to know that. What he says
about you privately I'd not venture to guess, although from my communication
with him, I think I have a pretty good idea.
> Other tests I did included attempting Parafeed using another well known
> Brand of Output Transformer (which to avoid more discussions about why I
> seem to criticise everything) added in parafeed mode to my Amplifers,
> reatining the original OPT as Choke. This sounded considerably worse than
> the Paraglow did when it was around. The OPT used was a PP-Unit, M6
> laminations and the original unit used as choke is airgapped, M6. Coupling
> Capacitor was 22uF Ansar Supersound.
>
> Tests in Preamp Outputs again showed that an airgapped SE Preamp OPT when
> converted to parafeed sounded considerably worse. on the other hand, using
a
> Studio Lineoutput Transformer in the same position (this had a large
amount
> of "better core laminations" (eg. Nickel, Permally, Mu-Metal) in it
sounded
> as good as the SE Preamp Output in it's native operation mode. Again, I
save
> myself more hassle by not mentioning any brands here.
Or details on how the tests were conducted, including how they may have been
vbiased to be predisposed to the testewr's agenda. Your assertions about
test proving this or that ring hollow now. You have been shown not to be an
unbiased researcher, but rather a prevaricator who designs these little
shows to support his POV. If you want to save yourself more hassle,
perhaps an apology to the list for all the misleading statements and out
right falshoods would be a place to start.
You may be a very talented engineer, but your credibility is on life
support.
Phil
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Magnetics and Distortion
Date: Mon, 23 Oct 2000 15:53:31 GMT
Source: Sound Digest Archive v02.n705
Phil,
>Enough of the disingenuous attempts to defend your dishonesty.
I think I'll leave it at that....
Tme to cool down.
Later T
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=========================================================================
From: "wmollard" <wmollard@dowco.com>
Subject: [JN] Magnetics, Distortion & High GM tubes
Date: Wed, 18 Oct 2000 19:07:48 -0700
Source: Sound Digest Archive v02.n699
Hey Folks,
Dan, I would be please to hear your thoughts on the 300 Hz Edgar; as
mentioned in a previous post I am replacing my 90 dbl speaks (again) with
something more sensitive. Today (!) the top end will be TAD 2001 and an
Edgar 500 Hz crossed at 750Hz to.... some tractrix bass thingie with Altec
515-8G. Anyone got a TAD 2001 (pre-1990) and/or Edgar Salad Bowel they want
to part with drop me a line.
Dave / Larry, your credibility as experimenters is what caused me to
investigate the "standard" approach. The real question regarding your
observed improvements in a 3way versus 2 way is what is happening and why
does it happen. What does increasing the drive current cause... a change in
the grid Z as a function of freq.; making it easier to move electrons to and
fro? Are there mo' electrons in the leading edge of a current waveform
transient making the grid more responsive to changes... leading to less
"bunching" of the electrons as they pass from cathode to plate (less
distortion). I must admit to focussing on theory at this point until I can
get some reasonable speakers so as I don't have to repeat all the
'speriments again; at least I don't have to build a chassis!
Bob D, I don't think the magnetic core resets to zero, rather there is
a remanence point having a +ve flux density (B) that is maintained when the
magnetizing force is removed; its where the falling magnetic curve crosses
the H=0. The same is with SE. Unless the pause in the music is... quite
long ;>).
Cheers
Bill
=========================================================================
From: Dan Marshall <mdaniel7@uswest.net>
Subject: Re: [JN] Magnetics, Distortion & High GM tubes
Date: Wed, 18 Oct 2000 20:12:36 +0000
Source: Sound Digest Archive v02.n699
I don't have them yet, but will get back to you when I have them and
have evaluated them.
DM
wmollard wrote:
>
> Hey Folks,
>
> Dan, I would be please to hear your thoughts on the 300 Hz Edgar; as
> mentioned in a previous post I am replacing my 90 dbl speaks (again) with
> something more sensitive. Today (!) the top end will be TAD 2001 and an
> Edgar 500 Hz crossed at 750Hz to.... some tractrix bass thingie with Altec
> 515-8G. Anyone got a TAD 2001 (pre-1990) and/or Edgar Salad Bowel they want
> to part with drop me a line.
>
> Cheers
> Bill
=========================================================================
From: "Larry D. Moore" <l-moore@onu.edu>
Subject: Re: [JN] Magnetics, Distortion & High GM tubes
Date: Thu, 19 Oct 2000 08:32:43 -0400
Source: Sound Digest Archive v02.n700
At 07:07 PM 10/18/00 -0700, you wrote:
>Hey Folks,
>
> Dan, I would be please to hear your thoughts on the 300 Hz Edgar; as
>mentioned in a previous post I am replacing my 90 dbl speaks (again) with
>something more sensitive. Today (!) the top end will be TAD 2001 and an
>Edgar 500 Hz crossed at 750Hz to.... some tractrix bass thingie with Altec
>515-8G. Anyone got a TAD 2001 (pre-1990) and/or Edgar Salad Bowel they want
>to part with drop me a line.
I now run 511B lenses w/ TAD 2001 on top and A7 515B on the bottom. This
weekend I will have custom made tratrix lenses of MDF.
> Dave / Larry, your credibility as experimenters is what caused me to
>investigate the "standard" approach. The real question regarding your
>observed improvements in a 3way versus 2 way is what is happening and why
>does it happen.
Being an EE, I always start from the following approach. Believe me, it is
hard to shake all that dogma that is put upon you in engineering school.
> What does increasing the drive current cause... a change in
>the grid Z as a function of freq.; making it easier to move electrons to and
>fro? Are there mo' electrons in the leading edge of a current waveform
>transient making the grid more responsive to changes... leading to less
>"bunching" of the electrons as they pass from cathode to plate (less
>distortion). I must admit to focussing on theory at this point until I can
>get some reasonable speakers so as I don't have to repeat all the
>'speriments again; at least I don't have to build a chassis!
Some things you can't explain or measure. I used to be in charge of
deciding and evaluating what test instrumentation Lucent/Bell Labs bought
for RF test applications. I had a ton o' stuff on my bench. Millions of
dollars. Vendors took me to lunch everyday. I even helped HP in the
design process by sitting on their design team. I used the best
instruments of all for testing my designs. My ears. At best, test gear
gets you in the ballpark, or as now on the subway...I still like Blackie's
runnin' da bus though :>)
Granted it has become easier since law school. I've learned a new way to
think. A new outlook on problem solving. Funny thing is what gives Dave
and I creditability with you is experimentation...not my education....well
may be experimentation is education....go figure.
If people would try something, they'd be amazed how much they
learn...rather than just post to and reading the list and being set in
stone. j is right. The proof is in the pudding. One's gotta get their
hands dirty...I'm always here to help. Feel free to disagree. I will
still help. Who knows you may teach me something.
> Bob D, I don't think the magnetic core resets to zero, rather there is
>a remanence point having a +ve flux density (B) that is maintained when the
>magnetizing force is removed; its where the falling magnetic curve crosses
>the H=0. The same is with SE. Unless the pause in the music is... quite
>long ;>).
>
>Cheers
>Bill
>
>
>
=========================================================================
From: Nicholas McKinney <nick@lambdacoustics.com>
Subject: Re: [JN] Magnetics, Distortion & High GM tubes
Date: Thu, 19 Oct 2000 12:05:30 -0400
Source: Sound Digest Archive v02.n700
At 07:07 PM 10/18/00 -0700, wmollard wrote:
>Hey Folks,
>
> Dan, I would be please to hear your thoughts on the 300 Hz Edgar; as
>mentioned in a previous post I am replacing my 90 dbl speaks (again) with
>something more sensitive. Today (!) the top end will be TAD 2001 and an
>Edgar 500 Hz crossed at 750Hz to.... some tractrix bass thingie with Altec
>515-8G. Anyone got a TAD 2001 (pre-1990) and/or Edgar Salad Bowel they want
>to part with drop me a line.
Hi Bill, I have about a dozen pre-1990 TAD2001 with new OEM diaphragms from a
Disney action left. I am interested, what is better about the earlier version?
Best regards
Nick
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
=========================================================================
From: "Snoopy" <tcma@netvigator.com>
Subject: [JN] Magnetic Suspension of Hartley Speakers
Date: Tue, 29 May 2001 23:36:01 +0800
Source: Sound Digest Archive v02.n895
Hi,
I am very lucky to obtain a pair of Hartley Concertmaster VI speakers
from the U.S. They arrived last night at the house of my friend. Each
speaker comprises a 24" superwoofer, a 10" fullrange driver, a 7" midrange
driver and a 2" tweeter. The cabinet measure 29" wide x 41.5" height x 18"
deep, with the back of the cabinet nearly open (with 70 square feet of
"Sound-sorber" acoustic material inside) as an infinite baffle for the 24"
superwoofer. The other three drivers are housed in a small closed box.
Except the tweeter, the drivers are alnico and equipped with the patented
MAGNETIC SUSPENSION.
The seller has enclosed some useful information regarding the Hartley
speakers. If you are interested, I can email you a 6-page Microsoft Word
file (around 100K) describing the MAGNETIC SUSPENSION of Hartley speaker and
its merits over the mechanical suspension of the traditional speaker.
I am also looking forward to hearing any ideas/opinions on this.
Best Regards,
Tung-cheung MA
HONG KONG
=========================================================================
From: Anders Blix <anders.blix@tv2.no>
Subject: [JN] Magnetisation of old magnets
Date: Mon, 28 Aug 2000 21:32:08 +0200
Source: Sound Digest Archive v02.n644
Hello everybody.
My tripp to Århus certainly gave me a lot of inspiration! So now I decided
to try to get a propper system up in my new house.
My friend Torbjørn Lien will supply me with 64 8" woofers for the bass
system. (Har du hentet dem enda Torbjørn???)
But from 500 Hz and ut to about 5 kHz or so I will make a ribbon.
I have about 150 kg ferrit magnets (yes a LOTT!!), but they are not fully
magnetized anymore. I had to heat them to about 300 degres C to sepparate
dem (melt the glue holding them).
Now I need to remagnetize them.
Annybody have experiense in that area???? Websites???
Have been on this list for more than 6 years, but have to scan it and read
only the interresting ones (from the header text). So it is possible that I
have overlooked something about it.
Anders Blix
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: [JN] Magnetisation of old magnets
Date: Tue, 29 Aug 2000 08:10:36 +0100 (BST)
Source: Sound Digest Archive v02.n644
Making a ribbon? I can hardly wait!
Magnetising magnets is easy enough if you can get the field. It is
usually done with a bank of capacitors to get enough current. The amount
of energy you need for a given magnetic material is proportional to the
volume of the magnets.
Simon
Simon Busbridge, BSc(Hons) PhD CPhys MInstP
School of Engineering
University of Brighton
Lewes Road
Moulsecoomb
Brighton BN2 4GJ
UNITED KINGDOM
Tel: 0044 (0)1273 642542
Fax: 0044 (0)1273 642327/642301
e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com
On Mon, 28 Aug 2000, Anders Blix wrote:
> Hello everybody.
>
> My tripp to Århus certainly gave me a lot of inspiration! So now I decided
> to try to get a propper system up in my new house.
>
> My friend Torbjørn Lien will supply me with 64 8" woofers for the bass
> system. (Har du hentet dem enda Torbjørn???)
>
> But from 500 Hz and ut to about 5 kHz or so I will make a ribbon.
>
> I have about 150 kg ferrit magnets (yes a LOTT!!), but they are not fully
> magnetized anymore. I had to heat them to about 300 degres C to sepparate
> dem (melt the glue holding them).
>
> Now I need to remagnetize them.
>
> Annybody have experiense in that area???? Websites???
>
> Have been on this list for more than 6 years, but have to scan it and read
> only the interresting ones (from the header text). So it is possible that I
> have overlooked something about it.
>
> Anders Blix
>
>
=========================================================================
From: Nicholas McKinney <nick@lambdacoustics.com>
Subject: Re: [JN] Magnetisation of old magnets
Date: Tue, 29 Aug 2000 16:37:33 -0400
Source: Sound Digest Archive v02.n645
At 09:32 PM 8/28/00 +0200, Anders Blix wrote:
>Hello everybody.
>
>My tripp to Århus certainly gave me a lot of inspiration! So now I decided
>to try to get a propper system up in my new house.
>
>My friend Torbjørn Lien will supply me with 64 8" woofers for the bass
>system. (Har du hentet dem enda Torbjørn???)
>
>But from 500 Hz and ut to about 5 kHz or so I will make a ribbon.
>
>I have about 150 kg ferrit magnets (yes a LOTT!!), but they are not fully
>magnetized anymore. I had to heat them to about 300 degres C to sepparate
>dem (melt the glue holding them).
>
>Now I need to remagnetize them.
>
>Annybody have experiense in that area???? Websites???
>
>Have been on this list for more than 6 years, but have to scan it and read
>only the interresting ones (from the header text). So it is possible that I
>have overlooked something about it.
>
>Anders Blix
Hello Anders,
I recently finished building a magnet charger from scratch.
If you are magnetizing just raw magnets it should be really easy to do.
The one I built was a good bit larger than you need as it has to magnetize an
assembled speaker motor (with the steel plates and pole).
It has 2 coils of 10 gauge wire with ~170 turns each. There is a low carbon
steel circuit with a gap in the middle to insert the magnet/motor. The entire
assembly probably weighs 400lbs or so (probably a bit bigger than needed, you
definitely do not need something this big)
I found I needed 70V to create enough amp/turns to push the magnets past their
"knee" and saturate the circuit. This was ~50,000 amp/turns to give an idea.
Basically you charge up a large capacitance bank slowly, then discharge it
quickly into the coils. The discharge process takes less than a second.
I used el cheapo starter solenoids from a Ford car for the switching ;-o
I have 2 solenoids in parallel and have zapped them about 200 times now with
only one failure.
The failure one solenoid stuck open after about a dozen zaps. Proper use of a
hammer solved that (It has never done it again)
Since these solenoids are about $5 each at a local auto parts store, its hard
to beat it cost wise.
Using these this way there is one catch, you need to have enough capacitance so
that the voltage never drops to zero. If you hit zero the coil fixture can
back charge the capacitors. Use just enough capacitance to have 20V or so
still left in the bank when the solenoids are turned off. For my unit I had to
use 0.5 Farad to give an idea.
To fire the solenoids I use a momentary switch and squeeze it as fast as
possible. You can never be too fast as the process is already complete in the
first few milliseconds.
I will take some pictures of my baby Frankenstien and get them uploaded if you
like.
I have already started designing its big brother with what I learned from this
one ;-)
For what you need you might be able to get away with just a coil of wire around
the magnet plus the power supply. It all depends on the magnet shape and the
location of the poles.
I have never heard about ceramic magnets losing their charge from high heat,
but then I think the data was only up to 150C or so. I wonder if any permanent
damage was done?
Best regards
Nick
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
=========================================================================
From: "Paul Croft" <pcroft@iximd.com>
Subject: RE: [JN] Magnetisation of old magnets
Date: Tue, 29 Aug 2000 21:20:58 -0400
Source: Sound Digest Archive v02.n645
Ah man, Nick, it sounds like you have a neat job!
I'd love to see some pictures of this beast.
Cheers,
Paul
> -----Original Message-----
> From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> Behalf Of Nicholas McKinney
> Sent: Tuesday, August 29, 2000 4:38 PM
> To: Anders Blix; Joenet (E-mail)
> Subject: Re: [JN] Magnetisation of old magnets
>
snip...
>
> Hello Anders,
>
> I recently finished building a magnet charger from scratch.
>
snip...
>
> It has 2 coils of 10 gauge wire with ~170 turns each. There is a
> low carbon
> steel circuit with a gap in the middle to insert the
> magnet/motor. The entire
> assembly probably weighs 400lbs or so (probably a bit bigger than
> needed, you
> definitely do not need something this big)
>
snip...
>
> The failure one solenoid stuck open after about a dozen zaps.
> Proper use of a
> hammer solved that (It has never done it again)
>
snip...
>
> I will take some pictures of my baby Frankenstien and get them
> uploaded if you
> like.
>
> I have already started designing its big brother with what I
> learned from this
> one ;-)
>
snip...
>
> Best regards
>
> Nick
>
> Nicholas McKinney
> Lambda Acoustics Inc.
> www.lambdacoustics.com
>
=========================================================================
From: Rick Francis <rfrancis@glasscity.net>
Subject: Re: [JN] Magnetisation of old magnets -- jc morrison, are you there?
Date: Tue, 29 Aug 2000 23:11:13 -0400
Source: Sound Digest Archive v02.n645
Nicholas McKinney wrote:
>
SNIP
>
> To fire the solenoids I use a momentary switch and squeeze it as fast as
> possible. You can never be too fast as the process is already complete in the
> first few milliseconds.
When I talked to jc morrison at nynoise, he was planning to do something
very similar, but was going to incorporate an extremely hefty mercury
ignitron as the switch, I think... Does anyone know if he got this
going?
Rick
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: [JN] magnetization / exploding wire
Date: Thu, 28 Jan 1999 10:02:26 +0100
Source: Sound Digest Archive v02.n015
- ----------
> De : PEARL Cust Serv <custserv@pearl-hifi.com>
> Date : jeudi 28 janvier 1999 02:47
> I found that by this method I could, invariably, get another dB of
> sensitivity out of any drive unit because no speaker manufacturer I know
of
> uses this method to charge magnets and therefore maximum enegry is not
> obtain in the voice coil gap...
Hello,
If memory serves me correctly several old loudspeakers like the Weber used
a magnetization coil that was used only one time. After having served to
magnetize the magnet, the coil stay in the magnetic circuit because it
couldn't be removed (the external part of the magnetic circuit was forged
in iron and had a spherical shape, the only hole in that iron was the gap).
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] magnetization / exploding wire
Date: Thu, 28 Jan 1999 10:38:43 -0600
Source: Sound Digest Archive v02.n015
"Le Cleac'h J.-M." wrote:
> ----------
> > De : PEARL Cust Serv <custserv@pearl-hifi.com>
> > Date : jeudi 28 janvier 1999 02:47
>
> > I found that by this method I could, invariably, get another dB of
> > sensitivity out of any drive unit because no speaker manufacturer I know
> of
> > uses this method to charge magnets and therefore maximum enegry is not
> > obtain in the voice coil gap...
>
I picked up an old military magnet charger (AN/GSM-1) at an antique gas engine
show a few years ago.
It is a capacitive discharge unit using a Thyratron tube as the "switch" which
dumps a 20mfd cap (@550vdc)
into a 100+lb transformer. The output windings are paralleled to a one turn
link (made of 1/2" by 1/4" copper bar) which went through what ever it was made
to charge.
As it is rated at 10,000 amp turns (with one turn) I have been able to charge
fairly large ceramic magnet assemblies with 5 turns of copper tubing as a coil.
Back in the old days I used to visit a speaker factory near by (called Heppner,
which was later bought out, stripped and sunk by Cerwin Vega). The magnet
charger they had in the lab was a home made job which used an "Equipto" shelf
full of Diehard car batteries connected in series. The main part of the thing
was made from some old machine tool (like a big milling machine etc) which had
an adjustable gap height (a motor turned a lead screw raising and lowering the
top part). The face of the gap iron was about 12 inches square and the portion
directly above and below the working gap had a coil made of 1/2 copper tubing
about 18" in dia and 18" long with a small pump to flow water through them for
cooling when used for production.
Welding sized cable went to a whopper home made knife switch located in the
next room for safety.
The assembled driver was placed in the gap and it closed until contacting the
driver (clamping it down).
Needless to say it was able to do any of the big magnets they dealt with at the
time.
One last thought, with the DC servo motors I am familiar with which employ
Alnico magnets, in the factory, they are full magnetized and then by applying
pulses of current and then are slightly demagnetized to a level which will not
be effected by normal operating current flux.
Alnico magnets, while having a long inherent leakage path can be easily
demagnetized (like removing them from the magnetic circuit or large pulse
currents in "normal" operation) so there peak maximum flux is somewhat greater
than that which is a stable level in normal operation.
"May the Flux be with you"
Tom Danley
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: Re: [JN] magnetization / exploding wire
Date: Thu, 28 Jan 1999 12:07:52 -0700
Source: Sound Digest Archive v02.n016
>Thomas Danley <Tom@ppci.com> wrote:
> "Le Cleac'h J.-M." wrote:
>
>> ----------
>> > De : PEARL Cust Serv <custserv@pearl-hifi.com>
>> > Date : jeudi 28 janvier 1999 02:47
>>
>> > I found that by this method I could, invariably, get another dB of
>> > sensitivity out of any drive unit because no speaker manufacturer I know
>> of
>> > uses this method to charge magnets and therefore maximum enegry is not
>> > obtain in the voice coil gap...
>>
>
> I picked up an old military magnet charger (AN/GSM-1) at an antique gas engine
> show a few years ago.
> It is a capacitive discharge unit using a Thyratron tube as the "switch" which
> dumps a 20mfd cap (@550vdc)
> into a 100+lb transformer. The output windings are paralleled to a one turn
> link (made of 1/2" by 1/4" copper bar) which went through what ever it was >
made to charge.
> As it is rated at 10,000 amp turns (with one turn) I have been able to charge
> fairly large ceramic magnet assemblies with 5 turns of
> copper tubing as a coil.
>
> In the old days I used to visit a speaker factory near by (called Heppner,
> which was later bought out, stripped and sunk by Cerwin Vega). The magnet
> charger they had in the lab was a home made job which used an "Equipto" shelf
> full of Diehard car batteries connected in series. The main part of the thing
> was made from some old machine tool (like a big milling machine etc) which had
> an adjustable gap height (a motor turned a lead screw raising and lowering the
> top part). The face of the gap iron was about 12 inches square and the
> portion
> directly above and below the working gap had a coil made of 1/2 copper tubing
> about 18" in dia and 18" long with a small pump to flow water through them for
> cooling when used for production.
> Welding sized cable went to a whopper, home made knife switch located in the
> next room for safety.
> The assembled driver was placed in the gap and it closed until contacting the
> driver (clamping it down).
> Needless to say it was able to do any of the big magnets
> they dealt with at the time.
>
> One last thought, with the DC servo motors I am familiar with which employ
> Alnico magnets, in the factory, they are full magnetized and then by applying
> pulses of current and then are slightly demagnetized to a level which will not
> be effected by normal operating current flux.
> Alnico magnets, while having a long inherent leakage path can be easily
> demagnetized (like removing them from the magnetic circuit or large pulse
> currents in "normal" operation) so there peak maximum flux is somewhat greater
> than that which is a stable level in normal operation.
>
> "May the Flux be with you"
>
> Tom Danley
==============================
Hi Tom:
Great story and it really IS a small world: about the time I was ready
to start building my pulse-discharge magger (1985-ish) I heard tell of the
VERY device you describe at Heppner, the name even rings a bell. That knife
switch scared me half to death so I learned about great BIG SCRs instead!
My device also has current-limited snubber diodes across the bank to
prevent ring down, but, more importantly, to prevent back "charging" the
bank and damaging the caps. I always treat electrolytics as though they are
undetonated hand grenades and this approach has saved my bacon more than
once I don't mind admitting...
The demag effects with my machine arose from the simple collapse of the
field generated by the coil, amps turns make flux snubbed or not...
At this point I'd like to say that the magger is, without doubt, the
most frightening thing I ever built. I'd never even SEEN such a beast when I
built mine, it was a completely seat-of-pants project. Talk about checking
your work!!! Well you know the sort of energy stored in a 50,000uF bank @
450V.
The thing about that project was that you only got to make one
mistake... and then you got seriously fluxed up....
=====================================================================
........ and with you as well, my Son.
Bill Perkins, PEARL Inc.
2528 19 St. S.W., Calgary, Ab.,
Canada T2T 4X3
Ph. 1 403 244 4434 Fx. 1 403 244 9026
=========================================================================
From: "Thomas Sylvester" <TRS@carlsmith.com>
Subject: [JN] Magnetization perils
Date: Thu, 31 Aug 2000 12:47:15 -1000
Source: Sound Digest Archive v02.n649
Of course Bill et al are right about the dangers of high VA pulse supplies. Power distribution syst
ems for high rise buildings typically operate on 480 v 3-phase power and carry hundreds of amps thro
ugh solid metal busbars. The circuit breakers for these systems must use special techniques to brea
k or quench the arc that results when the breaker opens under a fault condition; otherwise the plasm
a formed by the arc will quickly vaporize the breaker contacts. I've been involved (as a lawyer, no
t as someone who actually knows anything) in cases where workers have received severe flash burns fr
om this arcing when disconnecting energized equipment. In a recent fire case a phase-to-phase short
completely vaporized about two feet of an aluminum busbar that had a cross section of 21/2 x ½ inch
es; our expert estimated that instantaneous currents in the busbar had exceeded 100kA!
That being said, I still note that there are many amateurs that have safely harnessed similar PSs fo
r such things as electromagnetic rail guns, high-powered lasers, wire exploders and the like. Just
one example is "Fantastically Dangerous Capacitor Bank Experiments"
http://www.eskimo.com/~billb/amateur/capexpt.htm
And did you know that some tesla coil experimenters actually use 7kV/220v "pole pig" power pole step
down transformers backwards on house current to charge homemade 30kV capacitors to energize their co
ils? Check out
http://www.geocities.com/ResearchTriangle/Thinktank/3319/join.htm
I've always assumed that people on this list once warned, will take proper precautions to avoid elec
trocution (remember Doc Bottlehead's thread on this long ago?).
Regards, Tom Sylvester
"It's not good to let any kid near a container that has a skull and crossbones on it, because there
might be a skeleton costume inside and the kid could put it on and really scare you." J. Hadley, De
ep Thoughts
=========================================================================
From: "William Eckle" <wmeckle@qwest.net>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Sun, 27 May 2001 10:33:04 -0700
Source: Sound Digest Archive v02.n893
At 12:30 PM 5/27/01 +0200, Mattijs de Vries wrote:
>I am now playing music with my Altec 291-16A drivers coupled to the new
>ORIS 103 horns made by Bert Doppenberg.
>
>I am just wondering how the Altec 291 drivers compare to the 288 drivers.
>They look exactly the same on photos, what is the difference? From the
>material the 291 driver is made of, I can see it is a crystalline magnet
>and not Alnico. Is this in the type number (the A-version)? Are all 288's
>alnico? Can anyone explain this?
Hi Mattijs:
The Altec 291-16A compression drivers were made from 1968 to 1973, they are a composite diaphragm
version of the 288C, Has somewhat less high frequency performance and less transient response than
288s but more power handling. The 291s have Alnico V magnets and can be re-diaphragmed with
aluminum diaphragms from the 288 series (Altec #23763 for 8 Ohms and #23834 for 16 ohms), which most
prefer for "hifi" use in the home.
Starting with the K series the 288s were ferrite magnets.
Hope this helps.
<bold><color><param>ffff,0000,0000</param>-=Bill Eckle=-
</color></bold> wmeckle@qwest.net
<italic><color><param>0000,0000,ffff</param>Phoenix, Arizona USA
</color></italic>Vanity Web page at:
http://www.users.qwest.net/~wmeckle
=========================================================================
From: Mattijs de Vries <mattijs@machmat.com>
Subject: [JN] Magnet material for Altec 291 drivers
Date: Sun, 27 May 2001 12:30:01 +0200
Source: Sound Digest Archive v02.n893
Hello,
I am now playing music with my Altec 291-16A drivers coupled to the new
ORIS 103 horns made by Bert Doppenberg.
I am just wondering how the Altec 291 drivers compare to the 288 drivers.
They look exactly the same on photos, what is the difference? From the
material the 291 driver is made of, I can see it is a crystalline magnet
and not Alnico. Is this in the type number (the A-version)? Are all 288's
alnico? Can anyone explain this?
I am just wondering if there is still room for even more imrovement...
Thanks in advance for any replies.
_______
Mattijs de Vries, MachMat / _____ \
- ------------------------------------------------- | | ||| | |
E-mail: MdeVries@MachMat.com (Private) | | ||| | |
Sales@MachMat.com (Business) | | ||| | |
URL Tube information: http://www.machmat.com | | ||| | |
URL Tube sales : http://www.tubesforsale.com | |_____| |
Country: The Netherlands, Europe \ ||| /
Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
- ------------------------------------------------- |_____|
Designing is the art of making compromises. || ||
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Sun, 27 May 2001 14:22:10 -0400
Source: Sound Digest Archive v02.n893
Mattijs,
The Altec 291's with the composite diaphragm, are good for mid range up to
around 6000Hz. They are smooth and nice from there down to around
400-500Hz. I am assuming that you have something on top for high range?
How are they sounding with Doppenberg's horns?
I have a pair of 288K's with all aluminum diaphragms and tangerine phase
plugs and I've tested them and they aren't good for much above 14Khz.
Steve
Mattijs de Vries wrote:
> Hello,
>
> I am now playing music with my Altec 291-16A drivers coupled to the new
> ORIS 103 horns made by Bert Doppenberg.
>
> I am just wondering how the Altec 291 drivers compare to the 288 drivers.
> They look exactly the same on photos, what is the difference? From the
> material the 291 driver is made of, I can see it is a crystalline magnet
> and not Alnico. Is this in the type number (the A-version)? Are all 288's
> alnico? Can anyone explain this?
>
> I am just wondering if there is still room for even more imrovement...
>
> Thanks in advance for any replies.
> _______
> Mattijs de Vries, MachMat / _____ \
> ------------------------------------------------- | | ||| | |
> E-mail: MdeVries@MachMat.com (Private) | | ||| | |
> Sales@MachMat.com (Business) | | ||| | |
> URL Tube information: http://www.machmat.com | | ||| | |
> URL Tube sales : http://www.tubesforsale.com | |_____| |
> Country: The Netherlands, Europe \ ||| /
> Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
> ------------------------------------------------- |_____|
> Designing is the art of making compromises. || ||
=========================================================================
From: "Snoopy" <tcma@netvigator.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Sun, 27 May 2001 22:12:34 +0800
Source: Sound Digest Archive v02.n893
Hi,
As far as I know, the Altec 288H is the last alnico version, i.e. 288 ~
288H is alnico, whereas 288K, 288L is ferrite (or ceramic). I guess that
299 is similar to 288 which is usually equipped with aluminium diaphgram,
but with a different diaphragm called Pascalite. All the 288, 290, 291 and
292 models have 1.4" diameter horn throats. To my ears, the alnico one is
usually more 'tamed' than the ferrite (or ceramic) one. The Aluminium
diaphragm is more transparent than the Pascalite one (or Phenolic or
Symbotik adopted in other models such s 290, 291 or 292) which is thicker
(can go lower and with a higher power capacity) in sound. Some Joes who are
Altec experts may confirm and elaborate on this.
You may wish to take a look at: http://alteclansing.50megs.com/
Hope this helps.
Regards,
Tung-cheung MA
HONG KONG
=========================================================================
From: Mattijs de Vries <mattijs@machmat.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Sun, 27 May 2001 22:34:27 +0200
Source: Sound Digest Archive v02.n893
Hello All,
Are my Altecs really Alnico? I am really glad to hear that! Also if I use
the 288 diaphragm, are they the same then?
>The Altec 291's with the composite diaphragm, are good for mid range up
>around 6000Hz. They are smooth and nice from there down to around
>400-500Hz. I am assuming that you have something on top for high range?
I now use them in the range of 300 Hz (2nd order active) to 10 kHz
(passive). I enlarged the backchamber (to about 0.5 liter) of the driver,
this gave me more low frequencies. I only need about 0.1 watt, so they can
handle the excursions. I cannot hear any breakup, so I guess this works.
Amps are:
- - SE AVVT 302B-SL 2n order filtered (inside the amp) at 300 Hz for the
Altec drivers
- - 100W Solid state (Aaron 3 alike) amp for my basses (soon to be replaced
by two 80 watt PPP GU-50 monoblocks)
I will use some Decca ribbon supertweeters for the range 10kHz and up.
Below I now use a frontloaded horn and backloaded bassreflex (something
like the VOT) Altec 421-8H 2nd order filtered with a tube active filter.
Some pictures of the setup:
http://www.machmat.com/images/oris103-1.jpg
http://www.machmat.com/images/oris103-3.jpg
Some measurements of the system (done by Bert Doppenberg in my room):
http://www.machmat.com/images/altec-oris-pure.gif
Just the driver with original backchamber and no correction
http://www.machmat.com/images/altec-oris-corr.gif
The driver with original backchamber with a little correction network I
designed at the input of my power amplifiers
With the backchamber the frequncies below 500 Hz came a little up (to my
ears), there was a better connection between the drivers and my basses. We
didn't measure that unfortunately.
>How are they sounding with Doppenberg's horns?
The sound is very great. First it was a little hard, but you can imagine
when you see the first measurement. After the correction they really sound
very perfect, a lot of dynamics, very fast upto the highest frequencies.
And a lot of air, I can hear all little details very good loose from the
main music, that is very great!
>I have a pair of 288K's with all aluminum diaphragms and tangerine phase
>plugs and I've tested them and they aren't good for much above 14Khz.
Clearly the 291 stops a little sooner, at 10 kHz, so there is some need for
addition high frequencies. I still have to experiment with that.
We are planning to bring the Altec on the Oris horns together with my Decca
supertweeters and Jim de Korts Klipsch LaScala for basses (mine are just
too heavy and big ;((. Jim will bring some good SE amps and I will take my
GU50 80 watts monoblocks and my tube active crossover for the low
frequencies. This will be playing at Arhus, we are really looking forward
to that!
Bye,
_______
Mattijs de Vries, MachMat / _____ \
- ------------------------------------------------- | | ||| | |
E-mail: MdeVries@MachMat.com (Private) | | ||| | |
Sales@MachMat.com (Business) | | ||| | |
URL Tube information: http://www.machmat.com | | ||| | |
URL Tube sales : http://www.tubesforsale.com | |_____| |
Country: The Netherlands, Europe \ ||| /
Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
- ------------------------------------------------- |_____|
Designing is the art of making compromises. || ||
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Mon, 28 May 2001 19:42:02 -0700
Source: Sound Digest Archive v02.n894
>you are getting 10K out of that phenolic diaphragm - I mean at a db level
>anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
>> I will use some Decca ribbon supertweeters for the range 10kHz and up.
How low will your Decca's go ... the Decca is a pretty GOOD tweeter.
dave
______________________
Trust your ears, listen, practice often
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Mon, 28 May 2001 20:43:07 -0400
Source: Sound Digest Archive v02.n894
Mattijs,
Someone correct if perchance I am mistaken, but to my knowledge, you cannot
simply install a 288 diaphragm in a 291. The reason is that they configured
the alignment holes difference to prevent this. It could be done, but would
require somewhat expensive modification to the driver. I doubt seriously if
you are getting 10K out of that phenolic diaphragm - I mean at a db level
anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
Steve
Mattijs de Vries wrote:
> Hello All,
>
> Are my Altecs really Alnico? I am really glad to hear that! Also if I use
> the 288 diaphragm, are they the same then?
>
> >The Altec 291's with the composite diaphragm, are good for mid range up
> >around 6000Hz. They are smooth and nice from there down to around
> >400-500Hz. I am assuming that you have something on top for high range?
>
> I now use them in the range of 300 Hz (2nd order active) to 10 kHz
> (passive). I enlarged the backchamber (to about 0.5 liter) of the driver,
> this gave me more low frequencies. I only need about 0.1 watt, so they can
> handle the excursions. I cannot hear any breakup, so I guess this works.
>
> Amps are:
> - SE AVVT 302B-SL 2n order filtered (inside the amp) at 300 Hz for the
> Altec drivers
> - 100W Solid state (Aaron 3 alike) amp for my basses (soon to be replaced
> by two 80 watt PPP GU-50 monoblocks)
>
> I will use some Decca ribbon supertweeters for the range 10kHz and up.
> Below I now use a frontloaded horn and backloaded bassreflex (something
> like the VOT) Altec 421-8H 2nd order filtered with a tube active filter.
>
> Some pictures of the setup:
> http://www.machmat.com/images/oris103-1.jpg
> http://www.machmat.com/images/oris103-3.jpg
>
> Some measurements of the system (done by Bert Doppenberg in my room):
> http://www.machmat.com/images/altec-oris-pure.gif
> Just the driver with original backchamber and no correction
>
> http://www.machmat.com/images/altec-oris-corr.gif
> The driver with original backchamber with a little correction network I
> designed at the input of my power amplifiers
>
> With the backchamber the frequncies below 500 Hz came a little up (to my
> ears), there was a better connection between the drivers and my basses. We
> didn't measure that unfortunately.
>
> >How are they sounding with Doppenberg's horns?
>
> The sound is very great. First it was a little hard, but you can imagine
> when you see the first measurement. After the correction they really sound
> very perfect, a lot of dynamics, very fast upto the highest frequencies.
> And a lot of air, I can hear all little details very good loose from the
> main music, that is very great!
>
> >I have a pair of 288K's with all aluminum diaphragms and tangerine phase
> >plugs and I've tested them and they aren't good for much above 14Khz.
>
> Clearly the 291 stops a little sooner, at 10 kHz, so there is some need for
> addition high frequencies. I still have to experiment with that.
>
> We are planning to bring the Altec on the Oris horns together with my Decca
> supertweeters and Jim de Korts Klipsch LaScala for basses (mine are just
> too heavy and big ;((. Jim will bring some good SE amps and I will take my
> GU50 80 watts monoblocks and my tube active crossover for the low
> frequencies. This will be playing at Arhus, we are really looking forward
> to that!
>
> Bye,
> _______
> Mattijs de Vries, MachMat / _____ \
> ------------------------------------------------- | | ||| | |
> E-mail: MdeVries@MachMat.com (Private) | | ||| | |
> Sales@MachMat.com (Business) | | ||| | |
> URL Tube information: http://www.machmat.com | | ||| | |
> URL Tube sales : http://www.tubesforsale.com | |_____| |
> Country: The Netherlands, Europe \ ||| /
> Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
> ------------------------------------------------- |_____|
> Designing is the art of making compromises. || ||
=========================================================================
From: Rick Francis <rfrancis@glasscity.net>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Mon, 28 May 2001 23:03:41 -0400
Source: Sound Digest Archive v02.n894
Steve Van Osdell wrote:
> SNIP-- I doubt seriously if
> you are getting 10K out of that phenolic diaphragm - I mean at a db level
> anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
Steve, did you look at the CLIO measurements he posted in the following URLS???
Looks like he got 10K out of SOMETHING.
> > Some measurements of the system (done by Bert Doppenberg in my room):
> > http://www.machmat.com/images/altec-oris-pure.gif
> > Just the driver with original backchamber and no correction
> >
> > http://www.machmat.com/images/altec-oris-corr.gif
> > The driver with original backchamber with a little correction network I
> > designed at the input of my power amplifiers
- --Rick
Amount Treasury Secretary Paul O'Neill earned last year as CEO of Alcoa:
$56,400,000
Rank of Alcoa among the worst US polluters during O'Neill's tenure, according to
the National Wildlife Federation: 1
Harper's Index, June 2001
=========================================================================
From: Jeff Mai <j.mai.lists@home.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Tue, 29 May 2001 07:31:55 -0600
Source: Sound Digest Archive v02.n894
Mattijs,
Yes, the 291 diaphragms are aluminum, *not* phenolic. You must again
be thinking of the 290, Steve. I think we've gone through this
exchange before.
As far as I know, the 288 and 291 diaphragms *are* interchangeable.
I've done it and had no problems. There are two different styles of
diaphragms with regard to the mounting hardware needed, but I've seen
288 and 291 diaphragms of both styles.
The difference between the 291 and 288 is that the suspension and
voice coil former material are different. Whereas the 288 uses one
piece of aluminum for the suspension and diaphragm with a paper
former, the 291 uses one piece of aluminum for the diaphragm and
former with a synthetic material (Symbiotik was the trademark, I
think) for the suspension. Moving mass is higher and the suspension
isn't quite as stiff in the 291, resulting in less HF, but more LF
capability. I used mine to 300Hz with an active crossover.
I prefer the 291 to the 288 if used with a tweeter. It sounds better
to my ears below 1kHz. I wouldn't trade those diaphragms until you
can do the comparison yourself. You may prefer the ones you already
have.
Jeff
At 8:52 AM +0200 5/29/01, Mattijs de Vries wrote:
>Hello Steve,
>
> >Someone correct if perchance I am mistaken, but to my knowledge, you
> >simply install a 288 diaphragm in a 291. The reason is that they
> >the alignment holes difference to prevent this. It could be done, but
> >require somewhat expensive modification to the driver. I doubt
>
>That's to bad, I was doubting that also. I was thinking of replacing mine..
>
> >you are getting 10K out of that phenolic diaphragm - I mean at a db
> >anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
>
>I do not have Phenolic diapragms. My diaphramgs are aluminium, I do not
>know which type. Again a picture:
>http://www.machmat.com/sales/images/altec2.jpg
>See my other posting for the measurements of the Altec/Oris combination
>(and see how they get to 10 kHz ;))
>
>Maybe if I remagnetize the magnets, I get to 14kHz like the 288?
>
>Bye,
> _______
>Mattijs de Vries, MachMat / _____ \
>------------------------------------------------- | | ||| | |
>E-mail: MdeVries@MachMat.com (Private) | | ||| | |
> Sales@MachMat.com (Business) | | ||| | |
>URL Tube information: http://www.machmat.com | | ||| | |
>URL Tube sales : http://www.tubesforsale.com | |_____| |
>Country: The Netherlands, Europe \ ||| /
>Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
>------------------------------------------------- |_____|
>Designing is the art of making compromises. || ||
=========================================================================
From: Mattijs de Vries <mattijs@machmat.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Tue, 29 May 2001 08:52:05 +0200
Source: Sound Digest Archive v02.n894
Hello Steve,
>Someone correct if perchance I am mistaken, but to my knowledge, you
>simply install a 288 diaphragm in a 291. The reason is that they
>the alignment holes difference to prevent this. It could be done, but
>require somewhat expensive modification to the driver. I doubt
That's to bad, I was doubting that also. I was thinking of replacing mine..
>you are getting 10K out of that phenolic diaphragm - I mean at a db
>anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
I do not have Phenolic diapragms. My diaphramgs are aluminium, I do not
know which type. Again a picture:
http://www.machmat.com/sales/images/altec2.jpg
See my other posting for the measurements of the Altec/Oris combination
(and see how they get to 10 kHz ;))
Maybe if I remagnetize the magnets, I get to 14kHz like the 288?
Bye,
_______
Mattijs de Vries, MachMat / _____ \
- ------------------------------------------------- | | ||| | |
E-mail: MdeVries@MachMat.com (Private) | | ||| | |
Sales@MachMat.com (Business) | | ||| | |
URL Tube information: http://www.machmat.com | | ||| | |
URL Tube sales : http://www.tubesforsale.com | |_____| |
Country: The Netherlands, Europe \ ||| /
Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
- ------------------------------------------------- |_____|
Designing is the art of making compromises. || ||
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Tue, 29 May 2001 09:49:20 -0400
Source: Sound Digest Archive v02.n894
Mattijs de Vries wrote:
> Hello Steve,
>
>
>>Someone correct if perchance I am mistaken, but to my knowledge, you
>>simply install a 288 diaphragm in a 291. The reason is that they
>>the alignment holes difference to prevent this. It could be done, but
>>require somewhat expensive modification to the driver. I doubt
>>
>
> That's to bad, I was doubting that also. I was thinking of replacing mine..
It is mistaken. It's the 290 series that has the different alignement
holes.
>
>
>>you are getting 10K out of that phenolic diaphragm - I mean at a db
>>anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
>>
>
> I do not have Phenolic diapragms. My diaphramgs are aluminium, I do not
The 291s have (if original) what altec calls Symbiotic diaphragms, not
phenolic. The 290s have the phenolic diaphragms. Symbiotic diaphragms
look very much like aluminum diaphragms, but the surround is a
transparent (mylar?) plastic-like material, while the aluminum
diaphragms in the 288s have aluminum surrounds.
> know which type. Again a picture:
> http://www.machmat.com/sales/images/altec2.jpg
> See my other posting for the measurements of the Altec/Oris combination
> (and see how they get to 10 kHz ;))
>
> Maybe if I remagnetize the magnets, I get to 14kHz like the 288?
Only if you have the 288 style aluminum diaphragm.
Peace
- --
- --
Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe
"Once in a while you get shown the light
In the strangest of places if you look at it right." Robert Hunter
"640K ought to be enough for anybody" , Bill Gates, 1981
=========================================================================
From: Francois Yves Le Gal <flegal@free.fr>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Tue, 29 May 2001 10:25:37 +0200
Source: Sound Digest Archive v02.n894
At 19:42 28/05/01 -0700, you wrote:
>How low will your Decca's go ...
When properly filtered (very high slope) and used with their horn: London
from 1 KHz, DK-30 and derivatives from 2.5 KHz
In a "sawed" configuration, w/o horn, both shouldn't be used below 7 KHz or so.
>the Decca is a pretty GOOD tweeter.
More than that: it is excellent, despite it's numerous mechanical
shortcomings too often leading to premature failure.
=========================================================================
From: Robert Jorgensen <robert.jorgensen@advalvas.be>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Tue, 29 May 2001 08:03:10 +0200
Source: Sound Digest Archive v02.n895
Well assuming we are talking about the small horn Decca. To be quite
honest I can't quite keep the different names apart. There was a Decca
Kelly and a Decca London and I think the small one was the Kelly.
The smalll Decca should without to many problems be able to be set in
from 4 - 5 kHz. Lower than that they got quite ragged.
Greetings from Brussels
Robert
David Dlugos wrote:
>
> >you are getting 10K out of that phenolic diaphragm - I mean at a db level
> >anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
>
> >> I will use some Decca ribbon supertweeters for the range 10kHz and up.
>
> How low will your Decca's go ... the Decca is a pretty GOOD tweeter.
>
> dave
>
> ______________________
> Trust your ears, listen, practice often
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Tue, 29 May 2001 21:25:47 -0400
Source: Sound Digest Archive v02.n895
Mattijs,
Now I'm confused. I wasn't aware that aluminum diaphragms came in Altec 291A's
without aftermarket modification. To my knowledge, they came with phenolic.
That is the assumption which I based all my recommendations about frequency
response on. From your photograph, you have the Symbiotik aluminum phragms,
which will go higher than the phenolic, but not as high as the all AL. See the
brown 'mylar' looking surround? In all AL, this surround is quilted aluminum.
You can probably get 10-11K (12K max) from this phragm.
Rick, that explains my mistake and why he was getting the 10K. Thanks
Steve
Mattijs de Vries wrote:
> Hello Steve,
>
> >Someone correct if perchance I am mistaken, but to my knowledge, you
> >simply install a 288 diaphragm in a 291. The reason is that they
> >the alignment holes difference to prevent this. It could be done, but
> >require somewhat expensive modification to the driver. I doubt
>
> That's to bad, I was doubting that also. I was thinking of replacing mine..
>
> >you are getting 10K out of that phenolic diaphragm - I mean at a db
> >anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
>
> I do not have Phenolic diapragms. My diaphramgs are aluminium, I do not
> know which type. Again a picture:
> http://www.machmat.com/sales/images/altec2.jpg
> See my other posting for the measurements of the Altec/Oris combination
> (and see how they get to 10 kHz ;))
>
> Maybe if I remagnetize the magnets, I get to 14kHz like the 288?
>
> Bye,
> _______
> Mattijs de Vries, MachMat / _____ \
> ------------------------------------------------- | | ||| | |
> E-mail: MdeVries@MachMat.com (Private) | | ||| | |
> Sales@MachMat.com (Business) | | ||| | |
> URL Tube information: http://www.machmat.com | | ||| | |
> URL Tube sales : http://www.tubesforsale.com | |_____| |
> Country: The Netherlands, Europe \ ||| /
> Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
> ------------------------------------------------- |_____|
> Designing is the art of making compromises. || ||
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: Re: [JN] Magnet material for Altec 291 drivers
Date: Tue, 29 May 2001 23:25:12 -0400
Source: Sound Digest Archive v02.n895
Jeff,
You are right, I got confused with the 291's vs the 290's. I did have a pair of
291A's that had the phenolic diaphragms installed and this threw me off also.
Sorry about the confusion.
Thanks, Steve
Jeff Mai wrote:
> Mattijs,
>
> Yes, the 291 diaphragms are aluminum, *not* phenolic. You must again
> be thinking of the 290, Steve. I think we've gone through this
> exchange before.
>
> As far as I know, the 288 and 291 diaphragms *are* interchangeable.
> I've done it and had no problems. There are two different styles of
> diaphragms with regard to the mounting hardware needed, but I've seen
> 288 and 291 diaphragms of both styles.
>
> The difference between the 291 and 288 is that the suspension and
> voice coil former material are different. Whereas the 288 uses one
> piece of aluminum for the suspension and diaphragm with a paper
> former, the 291 uses one piece of aluminum for the diaphragm and
> former with a synthetic material (Symbiotik was the trademark, I
> think) for the suspension. Moving mass is higher and the suspension
> isn't quite as stiff in the 291, resulting in less HF, but more LF
> capability. I used mine to 300Hz with an active crossover.
>
> I prefer the 291 to the 288 if used with a tweeter. It sounds better
> to my ears below 1kHz. I wouldn't trade those diaphragms until you
> can do the comparison yourself. You may prefer the ones you already
> have.
>
> Jeff
>
> At 8:52 AM +0200 5/29/01, Mattijs de Vries wrote:
> >Hello Steve,
> >
> > >Someone correct if perchance I am mistaken, but to my knowledge, you
> > >simply install a 288 diaphragm in a 291. The reason is that they
> > >the alignment holes difference to prevent this. It could be done, but
> > >require somewhat expensive modification to the driver. I doubt
> >
> >That's to bad, I was doubting that also. I was thinking of replacing mine..
> >
> > >you are getting 10K out of that phenolic diaphragm - I mean at a db
> > >anywhere near what you need. I suggest you go down to 6 or 7K, 8K max.
> >
> >I do not have Phenolic diapragms. My diaphramgs are aluminium, I do not
> >know which type. Again a picture:
> >http://www.machmat.com/sales/images/altec2.jpg
> >See my other posting for the measurements of the Altec/Oris combination
> >(and see how they get to 10 kHz ;))
> >
> >Maybe if I remagnetize the magnets, I get to 14kHz like the 288?
> >
> >Bye,
> > _______
> >Mattijs de Vries, MachMat / _____ \
> >------------------------------------------------- | | ||| | |
> >E-mail: MdeVries@MachMat.com (Private) | | ||| | |
> > Sales@MachMat.com (Business) | | ||| | |
> >URL Tube information: http://www.machmat.com | | ||| | |
> >URL Tube sales : http://www.tubesforsale.com | |_____| |
> >Country: The Netherlands, Europe \ ||| /
> >Phone : +31-55-5332864, Mobile : +31-6-22988417 |/ | \|
> >------------------------------------------------- |_____|
> >Designing is the art of making compromises. || ||
=========================================================================
From: Timo Christ <carnivor@uni-bremen.de>
Subject: [JN] magnet systems
Date: Wed, 05 Apr 2000 16:18:09 +0200
Source: Sound Digest Archive v02.n510
Hello Joes,
Well, i recently played around with my bunch of hungarian compr. drivers
a little more, and found out how to completely disassemble the unit. I
can now acess the magnet, magnet-gap piece (a steel disc) and the steel
cup in which the magnet is mounted.
The magnet is a cylinder, app. 50mm diameter. I think it is Alnico, but
i'm not sure.
How can i determine if it is Alnico, what makes it different from
ferrite?
What's with the steel cup, i once read that "Alnico systems require the
biggest chunk of steel" or something to that effect by a popular driver
designer on this list. Why do you need it, what is it doing?
I have many of these drive units (40pcs) and could try some experiments
with the magnet system. For example i could attach 6 more magnets to the
driver, outside along the magnet gap, like in some of the newer
neodymium woofers. The present magnet is in the middle, where the pole
piece of a normal driver is.
These additional magnets would not fit in the steel cup.
You notice i have not much knowledge of magnet system + driver design,
but i would like to learn more.
Any pointers to helpful websites appreciated, as well as direct comments
to the abovementioned issues, of course.
Thank you very much, Joes!
Timo
- --
Timo Christ
EE Student University of Bremen, Germany
carnivore@uni-bremen.de
http://www-user.uni-bremen.de/~carnivor/
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] magnet systems
Date: Fri, 07 Apr 2000 22:46:53 -0400
Source: Sound Digest Archive v02.n514
Another thing I've noticed about alnico magnet drivers, and never seen
explained, is that they seem to not have significant external magnetic
fields. For example, an alnico 288 doesn't even attract a screwdriver
or wrench, but get one near a ceramic 288, and watch out! Anyone know
why? In terms I can actually understand?
Peace
- --
Roscoe Primrose
- -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe --
"Once in a while you get shown the light
In the strangest of places if you look at it right." Robert Hunter
=========================================================================
From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" <mdrivekl@online.no>
Subject: Re: [JN] magnet systems
Date: Sat, 8 Apr 2000 02:34:40 +0200
Source: Sound Digest Archive v02.n514
Hi Timo,
you wrote:
>
> Well, i recently played around with my bunch of hungarian compr. drivers
> a little more, and found out how to completely disassemble the unit. I
> can now acess the magnet, magnet-gap piece (a steel disc) and the steel
> cup in which the magnet is mounted.
> The magnet is a cylinder, app. 50mm diameter. I think it is Alnico, but
> i'm not sure.
> How can i determine if it is Alnico, what makes it different from
> ferrite?
>
With this dimension, being located on the inside of the iron cup, it should
be alnico, or some related cobalt-steel alloy. You will notice that it is a
hard, *metallic* alloy, wereas ferrite is a black ceramic material. Ferrite
mags
are due to a rather different operating-point always of the
"sandwich"/visible
type.
>
> What's with the steel cup, i once read that "Alnico systems require the
> biggest chunk of steel" or something to that effect by a popular driver
> designer on this list. Why do you need it, what is it doing?
>
It probably relates to the proportions of the mag-system. Alnico-mags
have a much higher "idling" working-point,(more flux-lines/area) and so
have lesser iron-area "contact" in the circuit. (The magnet itself are
usually
longer, making the completed circuit longer.) -BUT-, in well-designed,
economic mag-systems, you always see that the area of the mag-conductive
iron-path quickly encreases and gets much larger than the area of the
magnet itself. That way, the flux-density of the iron will be lower, so
iron-losses are minimized. One example would be the different sized JBL
drivers, the "small-pot" LE175, and the "big-pot" LE85. They have the same
sized magnet-ring, the same gap-width and height, but differs in gap
density
were the 85' is spec'd at 1,9 Tesla, the 175 at 1,75 Tesla. To my
knowledge,
this is only because the iron bell on the 85 is much wider, giving larger
iron area, lower flux.density in the iron-path, and so lower loss.
> I have many of these drive units (40pcs) and could try some experiments
> with the magnet system. For example i could attach 6 more magnets to the
> driver, outside along the magnet gap, like in some of the newer
> neodymium woofers. The present magnet is in the middle, where the pole
> piece of a normal driver is.
> These additional magnets would not fit in the steel cup.
>
[snip]
You can not increase the flux-density of your drivers by adding outside
magnets. They will be of no use as they cannot support anything to the
circuit,-
because they're on the outside of it. You have to wiev the mag-circuit as a
"gapped-loop" circuit. Think of how flux-lines "appears" in a
x-former-core. It's similar
in a speaker motor, except that the x-former "exiter"-coil here is
exchanged
with a permanent magnet inserted in series with the circular path made up
of iron
inseries with the airgap.
Your drivers are probably well-designed, magnet-vice, meaning you would
need substantially more magnet-mass, to encrease the flux. There are two
ways to do this:1: would be to exchange the magnet with a suitable sized
neodymium-ring, the other, if the iron bell is big enough, to exchange the
magnet with a same/bigger sized soft-iron piece, and then fill up rest of
the
interior with a suitable exciter coil....
You might then be able to push the working-point alittle higher, but not
much more than around 2 Tesla, then local saturation of the iron would
set in around the air-gap. This would be a good thing though, as saturated
iron has a perm. around 1, meaning that the "virtual" airgap has increased
in width, and that the iron flux-lines are "stiffer" so causing much less
evil,
in form of distortion, flux-modulation and inductive rise in impedance.
But,
it is a very costly thing to do,and probably not very practical.
If you want to improve on your drivers, you should rather look at the
short-circuit ring, and if absent, you should made one. It should be as
close
to the voisecoil as possible,-I have played alittle with jbl-drivers, and
so far
made new short-circuit-rings out of 1mm copper that I got heavily silver
plated.
Later, when I can afford to have the phase-plugs (centre-poles) and
top-plates
copper and silverplated aswell, the new short-circuit rings are to be
"parallelled" with the old ones (made of 3mm aluminium) and crimped in
place.
These efforts might improve on the inductive Z-rice and distortion,- but
then
maybe not that much.But, together with diaphragm/suspension mods,
who knows....
Lastly: You should know that when you disassemble a mag-system like this,
the flux-circuit is broken and so collapses. The alnico mag. are no longer
able to set up the same wrk. point when reassembling a unit, so the new
working-point will be well below the "knee" on the B-curve: A much weaker
and softer mag-system is the result, meaning that a reassembled unit is
considered useless before it is remagnetized. But with Alnico this is quite
easy,
and any decent speaker factory could provide this service...
HTH
Regards
Torbjoern, Norway
> You notice i have not much knowledge of magnet system + driver design,
> but i would like to learn more.
> Any pointers to helpful websites appreciated, as well as direct comments
> to the abovementioned issues, of course.
>
> Thank you very much, Joes!
> Timo
> --
> Timo Christ
> EE Student University of Bremen, Germany
> carnivore@uni-bremen.de
> http://www-user.uni-bremen.de/~carnivor/
>
=========================================================================
From: David Barnett <d_n_b@swbell.net>
Subject: Re: [JN] magnet systems
Date: Sat, 08 Apr 2000 17:03:17 -0500
Source: Sound Digest Archive v02.n515
On Sun, 09 Apr 2000 00:26:19 +0200, Torbjørn Lien <mdrivekl@online.no>
wrote:
>Yes, this is so..Aluminium and nickel aren't that pricey, but
>cobalt is,-and at one point in the late seventies, cobalt could
>If i remember right, only be had from Russia and South Africa.
>This was pricey, and politically bothersome..
I think that Uganda was a major source of cobalt, which became
difficult to obtain during the reign of Idi Amin Dada.
- --dnb
=========================================================================
From: rnevill <rnevill@is.dal.ca>
Subject: RE: [JN] magnet systems
Date: Sat, 8 Apr 2000 19:10:37 -0300
Source: Sound Digest Archive v02.n515
>===== Original Message From <@lightlink.com> =====
>Hi Timo,
>you wrote:
whole bunch of snipped stuff
Excellent post, most informative. Thanks!
Cheers
Richard Nevill
>HTH
>Regards
>Torbjoern, Norway
>
>
>
=========================================================================
From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" <mdrivekl@online.no>
Subject: Re: [JN] magnet systems
Date: Sun, 9 Apr 2000 00:08:24 +0200
Source: Sound Digest Archive v02.n515
Hello Timo.
>So far i have smoothed everything, there were some rough spots in the
>throat area, removed bug screen, filled phase-plugs with anti-resonant
>material.. etc mods like this. Of course i cleaned the units properly
>etc.
Hmm,-I cannot properly picture how your drivers are built,-
> filled phase-plugs with anti-resonant material.. <
How is this possible,-? Isn't the phaseplug the start of the throat?
Or is the "positive" or convex side of diaphragm on "outside" of motor?
> I don't see much room for diaphragm or suspension mods, other than
> making it heavier which i don't want.
> I thought about increasing the back volume, but discarded that idea.
Well,-you could judge the suspension-stiffness and maximum excursion.
With a softer surround and/or bigger back-chamber, your drivers might, with
the *appropriate* horns reach further down, frequency-vice. Or, if
suspension is very stiff, a softer surround and smaller back-chamber
(yelding the same f-resonnance ) might maybe improve on linearity.
>Adding a short-circuit ring would be nice. But where to attach it to?
The short-circuit ring is often attached on inside of top-poleplate were it
also serves as a "centering disc" for the centre-pole.
>The Magnet sits below a massive steel plate, which has the air gap in
>it. The steel plate itself conducts, so i don't know if a copper ring
>would help at all.
Iron is not that god a conductor,-and maybe even lesser at high
frequencies? But ofcourse, you need something substantial to be of any
use.I'll do like this: Silverplate both phaseplug and top-plate. Judged as
shorting rings, the plating alone is not of much help, but it will create a
*low* impedance path to the massive shorting ring below. That way, lo-z is
realized
very near voicecoil,- If you view the voicecoil as "primary coil" in an
x-former,
and the shorting ring as "secondary coil", the two are nearly at the same
place
in the mag-circuit,- so that "stray inductance" is minimized.
Think alittle further on this: When you drive your voicecoil with a
signal, you
want the magnetic field to be as *stiff and unmoving* as possible, to get
the
the voicecoil current transformed to voicecoil-motion without distortion.
I have
not tried electromagnets yet, but it's quite obvious that a well
constructed
one, driven from a stiff supply would be the ideal sollution...
(BTW A transformer works the same way: If we put a signal on the primary,
the
flux in the x-former core will vary with the signal. If we then short the
seconday,
flux variations will be very small (and determined by leakage inductance).
>Or does the copper ring help because it is non-magnetic but electrically
> conductive? hmm-that makes more sense.
Electrically conductive. You don't want it to be mag. conductive,-it would
pull field away from airgap.
>But sadly there is no way to acess the area beneath the steel plate
>where the magnet is located without disassembling the magnet assy. :-(
;) Well, get to know a person at a speaker factory..!
> > Lastly: You should know that when you disassemble a mag-system like
> >this, the flux-circuit is broken and so collapses. The alnico mag. are
no
> >longer able to set up the same wrk. point when reassembling a unit, so
> >the new
>but why? i don't get how the system parameters are changed just by dis-
>and reassembling it. Basically it's just a magnet enclosed by steel..?
The magnet is "loaded with flux-energy",-some of that energy is "used" when
the magnet has to magnetize the iron, and build up the field in the airgap.
This happens every time you reassemble a unit...So the field will get
weaker. When remagnetized, the whole driver is set in a magnetizing-pot,-
a *huge*, hollow electromagnet, that with a pulse, brings the whole
assembly
into magnetic saturation,-in this moment, all the flux-lines are now in one
direction only, parallel to each other, regardless of were you look at the
driver
assembly. At the end of pulse, the magnet itself is "fully charged" with
flux,-
and some of that is again used to *change* the field direction on the
outside
parts of the iron (180*),and in top and "bottom" plate (90*) and to build
up
field-strenght in the gap.
> > working-point will be well below the "knee" on the B-curve: A much
> >weaker and softer mag-system is the result, meaning that a reassembled
> >unit is considered useless before it is remagnetized. But with Alnico
this is
> >quite easy,and any decent speaker factory could provide this service...
>Oh! Fortunately i have only disassembled one unit so far.
>Now that you say it, i had the disassembled driver playing without and
>with steel cup, and it was by far not as loud as the other channel.
>Remagnetization would be too expensive and too much trouble for me i
>guess.
Well,-If you brought your drivers to the factory, it is a very simple
process, and should not cost much....
Regards
Torbjørn
=========================================================================
From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" <mdrivekl@online.no>
Subject: Re: [JN] magnet systems
Date: Sun, 9 Apr 2000 00:26:19 +0200
Source: Sound Digest Archive v02.n515
Hello Greg.
>
> I have been under the impression that until neodymium
> magnets became available, alnico was the most
> 'powerful', and that ceramics replaced them due to
> cost cutting.
>
Yes, this is so..Aluminium and nickel aren't that pricey, but
cobalt is,-and at one point in the late seventies, cobalt could
If i remember right, only be had from Russia and South Africa.
This was pricey, and politically bothersome..
>
> This was posted recently on another list by a driver
> manufacturer, and I'm curious if the info is correct.
>
> Alnico magnets will never give the kind of response
> you can get from a properly designed cold rolled
> steel plate/ceramic magnet design.
??
>The reason is that the saturation point of steel becomes
> your magnetic fluxs limiting factor. The saturation point of steel
> is around 19,000 to 21,000 gauss.
Yes,-
>The variance is due
> to carbon that is added for hardness.
> Alnico has a much lower flux density and thus if you design your
> magnetic gap to saturate the steel you can achieve
> higher motor strength.
Yes,-
Hm,-I must say I don't understand the meaning behind this. But it's not
the idling flux of ferrite (around 3000-4000 gauss I believe) or Alnico
(around 11000 gauss) that is the key to quality here,-but its the
*shape/angle*
of the magnetisation / demag. curves. I have never seen actual samples
of such curves, but been told by amongst others Ragnar Lian, that the
B-H angle is very different for the two materials at their respective
working
points. Meaning that ferrite has a less stable/more elastic field when
imposed
by mag forces from a working voisecoil,- and that alnico is much more
stable/
stiffer against flux modulation.. (But a good shorting ring could maybe
minimize
the differencies.)
Regards
Torbjoern
=========================================================================
From: Dan Kerl <dlkerl@ro.com>
Subject: Re: [JN] magnet systems
Date: Mon, 10 Apr 2000 12:41:13 -0500
Source: Sound Digest Archive v02.n516
Torbjxrn Lien wrote:
>
> Yes, this is so..Aluminium and nickel aren't that pricey, but
> cobalt is,-and at one point in the late seventies, cobalt could
> If i remember right, only be had from Russia and South Africa.
> This was pricey, and politically bothersome..
Actually, this was chromium, a key ingredient for most high-strength
steel alloys. Cobalt is still expensive, though.
- --
Dan Kerl
dlkerl@ro.com
=========================================================================
From: "Dave Slagle" <dslagle@earthlink.net>
Subject: [JN] magnet wire.
Date: Mon, 06 Sep 1999 12:14:58 -0400
Source: Sound Digest Archive v02.n272
hey,
i also scored a 32 lb roll of magnet wire, it is 19 ga, and the only
markings say something like
made in france
and Date Cast Nov 18 1978
would it be a huge leap for me to assume this is indeed cast copper? or is
the word cast generically used for wire that is drawn as well as cast?
It also seems odd that a 30 pound spool of 1978 french magnet wire would
find its way to a basement surplus place in NYC... 1978 wine, yes, but
magnet wire?
dave
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: [JN] magnet wire.
Date: Mon, 06 Sep 1999 15:00:55
Source: Sound Digest Archive v02.n272
A 12:14 PM 9/6/99 -0400, Dave Slagle a écrit :
>hey,
>
>i also scored a 32 lb roll of magnet wire, it is 19 ga, and the only
>markings say something like
>
>made in france
>
>and Date Cast Nov 18 1978
As I recall, that was a particularly good year for the Bordeaux magnet
wires, especially in the smaller gauges.
David Klein
=========================================================================
From: David Barnett <davidbarnett@aristotle.net>
Subject: Re: [JN] magnet wire.
Date: Mon, 06 Sep 1999 19:12:43 -0500
Source: Sound Digest Archive v02.n272
On Mon, 06 Sep 1999 15:00:55, "David B. Klein" <dklein@microtec.net>
wrote:
>>i also scored a 32 lb roll of magnet wire, it is 19 ga, and the only
>>markings say something like
>>
>>made in france
>>
>>and Date Cast Nov 18 1978
>
>
>As I recall, that was a particularly good year for the Bordeaux magnet
>wires, especially in the smaller gauges.
Is the wire aged on an oak reel?
- --dnb
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: [JN] magnet wire.
Date: Mon, 06 Sep 1999 21:25:12
Source: Sound Digest Archive v02.n272
A 07:12 PM 9/6/99 -0500, David Barnett a écrit :
>On Mon, 06 Sep 1999 15:00:55, "David B. Klein" <dklein@microtec.net>
>wrote:
>
>
>>>i also scored a 32 lb roll of magnet wire, it is 19 ga, and the only
>>>markings say something like
>>>
>>>made in france
>>>
>>>and Date Cast Nov 18 1978
>>
>>
>>As I recall, that was a particularly good year for the Bordeaux magnet
>>wires, especially in the smaller gauges.
>
>Is the wire aged on an oak reel?
>
>--dnb
>
Of course, but the real virtue of this particular vintage was the way in
which the warm, dry Bordeaux climate that year caused the lacquer to harden
to a crystalline structure of unparalleled purity and sonic sublimity in
which surface electron effects were reduced to an absolute minimum ...
David
=========================================================================
From: "gtrmkr" <gtrmkr@wans.net>
Subject: Re: [JN] magnet wire.
Date: Tue, 7 Sep 1999 01:54:12 -0400
Source: Sound Digest Archive v02.n272
Question regarding a domestic vintage...
Has anyone tried the Vampire cast magnet wire (20ga) that M. Percy sells?
In the recent issue of Valve, Doc. B. refers to cast 20.5ga magnet wire he
uses as hook-up signal wiring in a tricked-out Foreplay. Wonder if it's the
same stuff...?
Jim
A 07:12 PM 9/6/99 -0500, David Barnett a écrit :
>On Mon, 06 Sep 1999 15:00:55, "David B. Klein" <dklein@microtec.net>
>wrote:
>
>
>>>i also scored a 32 lb roll of magnet wire, it is 19 ga, and the only
>>>markings say something like
>>>
>>>made in france
>>>
>>>and Date Cast Nov 18 1978
>>
>>
>>As I recall, that was a particularly good year for the Bordeaux magnet
>>wires, especially in the smaller gauges.
>
>Is the wire aged on an oak reel?
>
>--dnb
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: [JN] magnet wire.
Date: Tue, 7 Sep 1999 08:56:26 +0200
Source: Sound Digest Archive v02.n272
> De : Dave Slagle <dslagle@earthlink.net>
> A : sound@lists.io.com
> Objet : [JN] magnet wire.
> Date : lundi 6 septembre 1999 18:14
> i also scored a 32 lb roll of magnet wire, it is 19 ga, and the only
> markings say something like
>
> made in france
>
> and Date Cast Nov 18 1978
Hello,
20 years ago I had to work on recycling processes for the mineral industry
For what I know, at that time copper products made in France were still
manufactured from first cast very pure copper (from Africa if I
remember...) and were excellent while copper parts from other countries
(Japan, USA, etc.) were manufactured from recycled copper needing many
difficult processes to achieved good quality...
( I don't know how that situation evolved since 20 years though)
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: "Sylvain Giguere" <pagebleu@globetrotter.qc.ca>
Subject: [JN] Mag or book...
Date: Fri, 22 Oct 1999 17:02:00 -0400
Source: Sound Digest Archive v02.n312
Message en plusieurs parties et au format MIME.
- ------=_NextPart_000_0247_01BF1CAF.285E81C0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Hi there,
Joe said: snip<Comments and suggestions always welcome. You heard it =
here first, folks!
>snip
Well Joe,
I have full confidence in you and your judgment and you are the one who =
knows what cost what... so, do your best, as usual. I remain a faithful =
subscriber, whatever the issue...
Long life to Sound Practices.
Sylvain Giguere
- ------=_NextPart_000_0247_01BF1CAF.285E81C0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
<HTML>
<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D'"MSHTML 4.72.2106.6"' name=3DGENERATOR>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000>Hi there,</FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>Joe said: snip<Comments and suggestions =
always=20
welcome. You heard it here first, folks!<BR>>snip</FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>Well Joe,</FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>I have full confidence in you and your =
judgment and you=20
are the one who knows what cost what... so, do your best, as usual. I =
remain a=20
faithful subscriber, whatever the issue...</FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>Long life to Sound Practices.</FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>Sylvain Giguere</FONT></DIV></BODY></HTML>
- ------=_NextPart_000_0247_01BF1CAF.285E81C0--
=========================================================================
From: Simmonds Mathews <mathews@txc.com>
Subject: Mailing List Help
Date: Tue, 19 Jan 1999 17:38:41 -0500
Source: Sound Digest Archive v02.n001
Hi all,
I am on the Golden Tube Audio Mailing list. If any one needs any
info on the set up files for the Joe list to be archived monthly, weekly or yearly,
you could contact the GTA List Owner Jeffrey D. Smith at "sumisu@nttlabs.com".
Jeff asked me to inform the folks at Joelist, after I mentioned to him about the thread on
archiving lists. Jeff started the Golden Tube Mailing List.
Simmonds Mathews.
=========================================================================
From: "Ron & Tamara" <ron.steinberg@sympatico.ca>
Subject: [JN] Mail Rules and JoeNet
Date: Tue, 23 Jan 2001 21:27:53 -0500
Source: Sound Digest Archive v02.n790
Hi All,
I'm a member of several mailing lists. I have been able to create "rules" in
outlook express for each one of them, so that a message say from Analogue
Audio goes into the AA folder. However, I can't seem to do this for Joenet.
The mail shows the "from" as being the original writer, and the "to" as
being me. Nowhere is "sound@lists.io.com" specified. Has anybody been able
to create a rule for Joenet? Is it possible to change the list server
software to accomodate this?
Thanks,
Ron S.
=========================================================================
From: "Ron & Tamara" <ron.steinberg@sympatico.ca>
Subject: Re: [JN] Mail Rules and JoeNet
Date: Tue, 23 Jan 2001 23:42:35 -0500
Source: Sound Digest Archive v02.n790
Thanks to all who responded to my inquiry, I should have thought of this!
Akhil asked about other analogue mail lists, I know of Phonogram but am not
a member.
Best to all,
Ron
( who's listening to streaming audio (jazz.fm) for the first time through
his stereo! Just got DSL today, yeah!)
> Hi Ron,
>
>>Has anybody been able
>> to create a rule for Joenet? Is it possible to change the list server
>> software to accomodate this?
>
> Yes, it can be done, Ron, but there's no need to change the list server
> software since it was done, I suspect, specifically for this reason anyway.
>
> A suitable rule works on the fact that all Joenet subject headers contain
> the [JN] descriptor.
>
> Under Tools|Message Rules|Mail, insert this:
>
> 'Where the Subject line contains '[JN]'
> Move it to the Joenet folder'
>
> Works for me.
>
> Of course, those sent to sound@deliverator.io.com I normally keep in 'Sent'
> anyway.
>
> Cheers,
>
> Hugh
>
>
> Hugh R. Dean
> Research/Technical Director
> www.printedelectronics.com
> Melbourne AUSTRALIA
>
>
=========================================================================
From: "Hugh R. Dean" <aksa1@optushome.com.au>
Subject: Re: [JN] Mail Rules and JoeNet
Date: Wed, 24 Jan 2001 14:55:05 +1100
Source: Sound Digest Archive v02.n790
Hi Ron,
>Has anybody been able
> to create a rule for Joenet? Is it possible to change the list server
> software to accomodate this?
Yes, it can be done, Ron, but there's no need to change the list server
software since it was done, I suspect, specifically for this reason anyway.
A suitable rule works on the fact that all Joenet subject headers contain
the [JN] descriptor.
Under Tools|Message Rules|Mail, insert this:
'Where the Subject line contains '[JN]'
Move it to the Joenet folder'
Works for me.
Of course, those sent to sound@deliverator.io.com I normally keep in 'Sent'
anyway.
Cheers,
Hugh
Hugh R. Dean
Research/Technical Director
www.printedelectronics.com
Melbourne AUSTRALIA
=========================================================================
From: "Remco Stoutjesdijk" <r.m.stoutjesdijk@student.utwente.nl>
Subject: RE: [JN] Mail Rules and JoeNet
Date: Wed, 24 Jan 2001 11:35:29 +0100
Source: Sound Digest Archive v02.n791
> A suitable rule works on the fact that all Joenet subject
> headers contain
> the [JN] descriptor.
>
> Under Tools|Message Rules|Mail, insert this:
>
> 'Where the Subject line contains '[JN]'
> Move it to the Joenet folder'
>
> Works for me.
Did for me too, but when people respond privately, it gets moved into that
folder as well.
I changed it to the following rule:
"with owner-sound@lists.io.com in the senders address, move it to the
JoeList folder and stop processing more rules"
The easiest way to create such a rule is to open one of the messages that
should be 'caught' by the rule in a separate window (so, double-click the
message), and then go to 'action->create rule' in the menu. A suitable
nummer of filtering suggestions is then offered readily.
Good luck,
Remco
- --
http://listen.to/rmsaudio
=========================================================================
From: "Remco Stoutjesdijk" <r.m.stoutjesdijk@student.utwente.nl>
Subject: [JN] major joy :D
Date: Mon, 2 Oct 2000 19:15:23 +0200
Source: Sound Digest Archive v02.n684
> >The guy who designed the 1541 told me he was aware that most
> players major
> >shortcoming is in the output stage, not the DAC.
>
> Yes, that squares with my experience. Go to
> www.bottlehead.com and download
> the current "Valve" Cybermag. It has a cute little article on DAC Valve
> stages by yours truely and much other cute stuff....
Thorsten,
I've read your article and forwarded it to 'some Idiot who integrated a
analogue stage based on the NE5532'. Guess what, it's the same guy as
above... :)
I'll let you know what, if any, his comments are...
*LOL*
Regards,
Remco
- --
http://listen.to/rmsaudio
=========================================================================
From: "PEARL Cust. Service" <custserv@pearl-hifi.com>
Subject: [JN] Make Peace, Was: the world is mad
Date: Thu, 13 Sep 2001 03:04:04 -0600
Source: Sound Digest Archive v02.n966
If you received this e-mail as an item forwarded even once, please remove
the "forwarding characters" appearing at the beginning of every line, tidy up
the line breaks and send it to everyone in your address book . . .
If you received an "original copy, please use "copy and paste" when you
forward
Please . . . . keep this work tidy and original.
It's intended to be viewed in a 78 character-wide space (check your
"Prefs") and the formatting is *critical*
I have nearly five hours, until 3:00 AM, into this and it had been a long
day when I started
- --------------------
Steve observed:
> I think we should think long and hard before we do EXACTLY as Usama
> Ben Laden expects us to do. Why should we do the very thing that he is trying
> to provoke us to do? If for no other reason, this would give me reason (were
> I the President) to think long and hard, and consider and reconsider all
> angles.
SNIP
> As bad as the tradegy was, we can only thank God that it wasn't a mushroom
> cloud over New York that we witnessed. And if our 'petty politics' officials
> don't wake up, and if we don't stop voting for the same 'crapheads' time after
> time, I'm afraid that we might wake up to that sight in the near future.
>
> Steve
Hello All:
Given what could have just as easily happened, we are fortunate indeed
that there are any pieces at all to put back together.
By that I mean that if only a few LNG tanker-docking/storage facilities
had been hit, an unstoppable firestorm would have swept a 5 x 100 mile swath
clear off the eastern seaboard.
We play with too much fire in our quest for "the good life."
Regarding the prospect of a *n*u*k*e/*b*i*o* calamity: why would anyone
even entertain the notion that those weapons are not already here . . . right
here . . . under our sleepwalking noses?
Given the state of ** extreme ** alert that anyone could have predicted to
follow on the heels of the initial salvo, what strategist capable of making
his own coffee would attempt to smuggle his armaments into enemy territory
once the enemy had been given such cause to push every "Red Alert" button at
his disposal.
It's no great leap to conclude that there is a ** MASSIVE ** intelligence
operation underway to discover those weapons' whereabouts. . . . Right ? ?
We NEED to focus the ***** POWER ***** of our collective mind onto the
achievement of those discoveries. . . . wherever those weapons are.
By this I do NOT mean sitting, quivering in the darkness of fear, hoping
against hope that the news will soon be good.
What I DO mean that we must PRO-ACTIVELY imagine that we are hearing and
seeing the newscasts that those weapons are being discovered, whether through
good management, good work, collective prayer, good luck, happy coincidence,
synergy, synchronicity, divination, remote viewing, tarot reading, psychic
help, by stubbing your toe on a odd looking suitcase, a fluke of Nature, an
act of God or all of the foregoing
Collectively, our "power to" is incalculably vast . . . We tap the very
Heart of Creation when we, with ** pure intention ** set about a task.
Creation's response is instantaneous . . . cutting across time as it does
at the speed of love.
Most do not know this . . all must learn it and soon.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
"Come to the Edge," he said.
They said, " We are afraid . . . "
"Come to the Edge," he said.
They went . . . he pushed them . . .
And they flew,
For they had Wings, though not they knew
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
The "war," in case you haven't figured it out yet, is a distraction
away from the near certainty that those weapons are in our midst.
The "war" is not a war at all . . . it's a sideshow, a diversion.
Its purpose is to convert the terror of a populace otherwise looking
down the barrel of the cannon of its own demise into a projection of
anger at someone "over there," to focus itself on the destruction of
"them," "over there."
That said however, it's equally obvious that the "enemy" would be
delighted to take the brunt of an attack -- played out on the world stage --
as it would then be in a "more tenable" position to make its next move.
In this game, we are in checkmate and the next move ** is not ours **
The rational "move" at this point is to do ABSOLUTELY NOTHING AT ALL
beyond the triage and cleanup operations and the buying of time . . . .
precious time in which to reflect deeply on this situation in ALL of its
aspects, and the methods and means by which it can be most quickly and
effectively contained . . .
Precipitate action is foolhardy in the extreme . . . .
Vengeful action is suicidal . . .
. . and WE get to choose . . . . we ARE choosing our future.
The future will we inhabit is the very future
WE ARE NOW IMAGINING FOR OURSELVES . . .
If you want peace, then from your heart -- the most powerful organ within
you and center of your intelligence -- radiate peace, and harmony, and
forgiveness and healing with every step and through every breath.
Walk peace, talk peace, live peace, pray for peace, meditate peace, join a
group that prays for peace, listen to music that brings you peace, talk peace
within your family and at your workplace.
Think peace driving in your car, looking out train windows, riding in
elevators, in line at the bank, in taxis, on airplanes, in buses and on your
mountain bike . .
Make love in peace . . .
Talk to strangers in restaurants and bars, at bus stops, in barber shops,
at news stands and in the checkout line at the food store . . .
Discover that they are not strange at all.
Discover that they are spun from the same skein that you are, find out
that they are struggling in much the same ways that you are, make friends
with them, smile at them, look deeply into their eyes, touch them and tell
them your dreams of peace, make peace with them.
Tell them what you are doing and tell them WHY you are doing it and ask
them to do likewise . . .
Forward or photocopy this e-mail or write one like it and give it away in
handfuls. . . . leave a stack in your coffee shop, in a taxi, on a bus . .
anywhere . . everywhere.
Make the spreading of the feeling, the idea, the vibration of peace the
NUMBER ONE PRIORITY in your life . . because, truly, nothing else has EVER
mattered.
- - - - - - - - - - -
Try to imagine the Magnificence of your Soul, your Spirit, your Eternal
Self . . . .
It doesn't matter if you "think" you can or not, just try . . . .
Remember images of outer space, the stunningly beautiful pictures of
galaxies and star fields . . imagine the calm, the silence . . the Ancient and
Magnificent Order . . . .
Imagine the Perfection and the Mystery of it all . . .
It is so, so beautiful . . . remember ? ?
Go to the Hubbell telescope site and remind yourself of the beauty of the
inhabitable work of art within which and of which we ARE . . . .
ALL of us . . .
Imagine the harmony within the Mind of Creation . . . .
Bring that harmony into yourself . . . re-join with it . . . .
It's not just "out there" . . .
It's part of you, you know . . and you are part of it . . . remember ? ?
You are spun from it . . . . Yes ? ?
Re-imagine your own Magnificence . . . . hold that, cherish it . . . .
Imagine the Magnificence of others . . . . ALL others . . . .
Cherish that too . . . maybe for the first time in your life . . . .
We are ALL spun of the same yarn . . . . We are ALL Magnificent . . .
even terrorists . . .
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
This . . . . .
This is Peace . . . .
Imagine it . . . .
Create it . . . . .
Live it . . . . .
Build with it . . . . .
Forge it into new relationships. . . . .
Make peace . . . . .
Create peace . . . . .
Build peace . . . . .
Imagine peace and . . . . .
Spin peace and . . . . .
Let peace be and rebuild. . . . .
Flow into peace and refashion. . . . .
Feel peace and repair your. . . . .
Join others in peace and reunite our. . . . .
Remember peaceful times and rebuild your. . . . .
Imagine peace in our lifetime and rebuild our. . . . .
MAKE PEACE AND REBUILD YOUR WORLD
JOIN IN PEACE AND REFASHION OUR WORLD
IMAGINE A PEACEFUL WORLD AND CREATE
A FUTURE FOR OUR CHILDREN
. . . . MAKE PEACE . . . . .
. . . . . PLEASE . . . . .
=========================================================================
From: "Thomas Sylvester" <TRS@carlsmith.com>
Subject: [JN] Make your own wood horns
Date: Tue, 20 Mar 2001 10:58:18 -1000
Source: Sound Digest Archive v02.n838
http://member.aol.com/araiyuichi/
=========================================================================
From: Rick Francis <rfrancis@glasscity.net>
Subject: [JN] Re: Making historical instruments sound like ... WHAT?
Date: Mon, 09 Aug 1999 12:13:40 -0400
Source: Sound Digest Archive v02.n231
At 11:58 AM 8/9/99, you wrote:
>
>It's obvious that my stereo can't make a Streicher fortepiano from Vienna,
>ca. 1815 sound like it did when it was new. That is another fidelity issue
>which is the preoccupation of instrument restorers and replica builders,
>and it's certainly a Pandora's box.
So your reference is simply your memory of the sound of a instrument, and
you aren't claiming special insight. Fine. Incidentally, I wonder how you
would ever KNOW when the Streicher fortepiano sounds like it did in 1815? I
thought this was your claim about making historical instruments sound like
themselves.
>
>My humble stereo can only attempt to produce some approximation of the way
>an instrument, be it original or replica, would sound live in 1999. But if
>this is done well, it enables me to communicate with a builder in Berlin
>about which of his replicas sounds "earlier," or has more interesting tonal
>colors, or whatever. And each of us will know what the other is talking
>about, because he has the instruments in his shop, and I have a stereo that
>doesn't get in the way of reproducing the original timbres.
So you sound like everyone else on the list. In an imperfect world, you're
looking for a means to reproduce, subjectively, the sound as you believe it
should be, according to your experience. Welcome to the club. Your "proof"
is merely that to you it sounds more "right."
I wonder why you imagine you have the magic handle on this rightness, while
telling the rest of us subjectivists we are deluded in what sounds right to
us? Plenty of us have experience with live music. This all seems highly...
er, irrational. Perhaps you should reconsider your list ambitions, or
redefine them.
Rick
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: [JN] Re: Making historical instruments sound like ... WHAT?
Date: Mon, 09 Aug 1999 12:41:01
Source: Sound Digest Archive v02.n231
A 12:13 PM 8/9/99 -0400, Rick Francis a écrit :
>I wonder why you imagine you have the magic handle on this rightness, while
>telling the rest of us subjectivists we are deluded in what sounds right to
>us? Plenty of us have experience with live music. This all seems highly...
>er, irrational. Perhaps you should reconsider your list ambitions, or
>redefine them.
>
>Rick
A couple of important differences: I use acoustical music as a reference,
and I use the most distortion-free devices available to me. Although I own
tube gear and have built tube gear, I currently feel SS stuff brings me
closest to what I hear live. YMMV. My point about fortepianos was that
their very subtle colors seem to come through best on transistorized
equipment. Again, YMMV.
Another point: tubes make the fiddles sound silky. But when I sit not too
far from the (modern) orchestra, they sound steely to me. The mikes usually
hang over the string section. What people don't like is the
honest-to-goodness sound that you would hear hanging from your toes 8 feet
above the orchestra. That's the fault of the engineers.
My sonic ideals are formed from careful listening to live performances. And
- - at least at the moment - I find decent SS gear with EQ gets me closest to
that. YMMV.
In any case, the whole damn thing is pretty imperfect, compared to the live
sound. The art has a long way to go ... remember that people 80 years ago
thought their acoustic gramophones sounded exactly like the real thing!
dbk
=========================================================================
From: Rick Francis <rfrancis@glasscity.net>
Subject: Re: [JN] Re: Making historical instruments sound like ... WHAT?
Date: Mon, 09 Aug 1999 14:35:53 -0400
Source: Sound Digest Archive v02.n232
At 12:41 PM 8/9/99, David B. Klein wrote:
>A 12:13 PM 8/9/99 -0400, Rick Francis a écrit :
>
>>I wonder why you imagine you have the magic handle on this rightness, while
>>telling the rest of us subjectivists we are deluded in what sounds right to
>>us? Plenty of us have experience with live music. This all seems highly...
>>er, irrational. Perhaps you should reconsider your list ambitions, or
>>redefine them.
>
>A couple of important differences: I use acoustical music as a reference,
Sure, you and perhaps most of the people on the list. Why do you assume
that this is a DIFFERENCE between you and others on this list??? Why it
just ain't rational.
>Another point: tubes make the fiddles sound silky.
Uh... are you saying that ALL tube amplifiers sound the same, and that
sameness is an inaccuracy? Maybe you should get out and hear some
different amps. Rational, my foot. Maybe odd-order distortion and phase
shift sounds good to you?
>
>My sonic ideals are formed from careful listening to live performances.
Many of us are regular concert-goers, season-ticket-holders to the
symphony/opera. We have performers and recording engineers on the list. I
guess we just don't listen as closely as you, huh? I wonder how you knew.
I'm still amazed at this parapsychic ability you call rationalism. Maybe
we should call it "para-rationalism"?
Rick
=========================================================================
From: Rick Francis <rfrancis@glasscity.net>
Subject: [JN] Making historical instruments sound like ... WHAT? WAS Re: [JN] Binding & fuel oil
Date: Mon, 09 Aug 1999 11:14:55 -0400
Source: Sound Digest Archive v02.n231
At 09:56 AM 8/9/99, David B. Klein wrote:
>A 09:27 AM 8/9/99 -0400, John Levreault a écrit :
>
>>So I'm curious, David: Why are you here on this mail list?
>>
>>JL
>
>Something also puzzles me: If your game is about approaching sonic truth,
>as some folks on this list claim, then making historical instruments sound
>like themselves has got to be the proof of the pudding ...
>
>dbk
>
All this needs is a tiny bit of irony to be hilarious. How in the world
can you know when you've got a 19th
C. instrument sounding "like itself"? This is the stuff of parody, not
rationality. "Sonic truth" indeed.
I envision a whole room of HIPsters arguing about the "proper" sound of
something they could never hear, like the celestial music of the spheres.
If this be your proof, then you're the king of subjectivity, not
objectivity. Because of course, YOUR real is more real, objectively, than
anyone else's real, right? :)
That Detroit group of "rational" guys is equally amusing, with all their
trappings of scientific approach, and almost none of the understanding. I
think you belong, David. I'll send their address.
Rick
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: [JN] Re: Making historical instruments sound like ... WHAT? WAS Re: [JN] Binding & fuel oil
Date: Mon, 09 Aug 1999 11:58:36
Source: Sound Digest Archive v02.n231
A 11:14 AM 8/9/99 -0400, Rick Francis a écrit :
>At 09:56 AM 8/9/99, David B. Klein wrote:
>>A 09:27 AM 8/9/99 -0400, John Levreault a écrit :
>>
>>>So I'm curious, David: Why are you here on this mail list?
>>>
>>>JL
>>
>>Something also puzzles me: If your game is about approaching sonic truth,
>>as some folks on this list claim, then making historical instruments sound
>>like themselves has got to be the proof of the pudding ...
>>
>>dbk
>>
>All this needs is a tiny bit of irony to be hilarious. How in the world
>can you know when you've got a 19th
>C. instrument sounding "like itself"?
We're talking about two stages of reproduction here: the historical
instrument, and the recording/playback process.
It's obvious that my stereo can't make a Streicher fortepiano from Vienna,
ca. 1815 sound like it did when it was new. That is another fidelity issue
which is the preoccupation of instrument restorers and replica builders,
and it's certainly a Pandora's box. Streicher used about 7 layers of
leather to cover the hammers - and all were not the same. Can anyone get
the hammer to hit the string with exactly the sound it made in 1815? How
humid was the original leather? How was it tanned? How were the layers
glued? The builders and restorers do the best they can, using what research
techniques are available, and studying extant instruments in museums and
private collections, but they don't claim to have absolute truth. What
these folks do is really fascinating, though. They are practicing their own
blend of art and science ...
My humble stereo can only attempt to produce some approximation of the way
an instrument, be it original or replica, would sound live in 1999. But if
this is done well, it enables me to communicate with a builder in Berlin
about which of his replicas sounds "earlier," or has more interesting tonal
colors, or whatever. And each of us will know what the other is talking
about, because he has the instruments in his shop, and I have a stereo that
doesn't get in the way of reproducing the original timbres.
dbk
=========================================================================
From: StepHydro@aol.com
Subject: [JN] Making low value power resistors
Date: Mon, 12 Apr 1999 09:46:26 EDT
Source: Sound Digest Archive v02.n121
A web search turned up nothing on this topic. I remember reading about this
40 years ago in a ham radio handbook, but I find that my memory isn't 100%
clear at such a distance in time. Maybe some of the more experienced members
has a method for me.
I need a number of resistors, of about 10W dissipation, in the range of 0.7
to 0.8 Ohms, trimmable. I have a good bit of 10mm dia. ceramic rod which
might make a good winding form (knife-sharpening stones), but I don't know
the best wire to use.
The first thing that comes to mind is copper magnet wire, selecting a
diameter that will carry the load (1.75 A + a safety factor) and just winding
until I am a bit above the upper target value. Is there a better wire than
for this application? Nichrome is easily available, but it would be necessary
to have an easy way to bond *that* wire to some copper for connection in the
circuit. Is nichrome solderable?
These resistors will drop 5VAC down to 2.5VAC for DHT filaments, so they will
be in the signal path. Would it be preferable to bifilar wind them to kill
the inductance, or is that so low in these small values that it won't matter.
If bifialr, is it enough to start on one end with a narrow loop and just wind
two wires back to the other end, ending with both connections at that end, or
must the two coils be wound in opposite "sense"?
I expect that I'll take out the form, after winding, and mount the wound
resistor coils in the air above my breadboard using barrier strips.
TIA/Carron
who has proper 2.5VCT transformers coming, but is a bit impatient to get on
with building and testing.
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: [JN] Making low value power resistors
Date: Mon, 12 Apr 1999 16:26:28 -0400
Source: Sound Digest Archive v02.n121
Carron asked:
>>>I need a number of resistors, of about 10W dissipation, in the range of
0.7
to 0.8 Ohms, trimmable<<<
How about a bunch of ~8R wire wounds or 1 watt regulars in parallel?
Add/subtract a few to get the current/voltage drop you want?
Allen (VSE)
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] Mall Rules and JoeNet
Date: Wed, 24 Jan 2001 00:06:31 EST
Source: Sound Digest Archive v02.n790
- --part1_13.107e9bba.279fbcd7_boundary
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Greets!
No Skateboards!
No MP3!
No ground loops!
No rules!
Happy Ears!
Al B^}
- --part1_13.107e9bba.279fbcd7_boundary
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>Greets!
<BR>
<BR>No Skateboards!
<BR>
<BR>No MP3!
<BR>
<BR>No ground loops!
<BR>
<BR>No rules!
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR>
<BR></FONT></HTML>
- --part1_13.107e9bba.279fbcd7_boundary--
=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: Re: [JN] Manfred,Phil
Date: Sun, 17 Dec 2000 10:48:57 -0500
Source: Sound Digest Archive v02.n761
Mick,
>
> Phil's "sakuma" circuit is just inspirational-lots of iron, lots of good
> vibes just from looking at the circuit-I bet it's a killer!
You are too kind. I like it well enough to convert my dc45s to this
topology. And to likely add a 71A tweeter amp of similar topology. then I
can save up for the truss I'll need after schlepping these things around.
;-)
Phil
=========================================================================
From: "Michael (Mick)Maloney" <supra@cantech.net.au>
Subject: [JN] Manfred,Phil
Date: Sun, 17 Dec 2000 19:05:11 +0800
Source: Sound Digest Archive v02.n761
It's been a while since I've seen anything of real interest in the digests
as far as DIY goes and then two gems in one day!
Manfred and Phil I suspect come from different philophosies, forgive me if
I'm wrong, but both generous contributions were very welcome from my
perspective.
Manfred, if you can find the time could you give a description of your
current reg and how it works?
From a technical view it's very interesting and I suspect it sounds good too.
Your TL431 shunt reg for the 6A3's bias, off the power tranny is also very
neat and innovative-took me a while to figure it out though-there's a few
mazes in that circuit!
Phil's "sakuma" circuit is just inspirational-lots of iron, lots of good
vibes just from looking at the circuit-I bet it's a killer!
MickM
=========================================================================
From: MHuber@t-online.de (Manfred Huber)
Subject: Re: [JN] Manfred,Phil
Date: Mon, 18 Dec 2000 22:57:12 +0100
Source: Sound Digest Archive v02.n762
Hello Michael,
>Manfred, if you can find the time could you give a description of your
>current reg and how it works?
Thanks for your interest. I will try to explain how it works.
The LM4041 is an integrated shunt voltage regulator. It measures the
voltage from it's pin 8 to it's pin 5 and tries to keep this voltage constant by
draining a variable current from pin 8 to pin 4. If the voltage from pin 8
to pin 5 gets larger more current is drawn. You find the LM4041 data sheet
on the National Semiconductor web site.
R12,R13 and R14 are the current sensing resistors. I used a series/parallel
connection of three resistors to get the desired value. Ideally you
use a single resistor with the correct value at this position.
The needed value depends on the current you want the CS to supply.
Rsense=1.25V/Iout.
Q1 is a high current p-channel enhancement mosfet. It works as
the pass transistor.
The regulator loop works like this: Let's assume the outout
current is too high. This means that too much current is
flowing through the sense resistor and the voltage across
the sense resistor is high. This voltage is measured by the
LM4041 and as mentioned above the LM4041 increases the current
flowing from pin 8 to pin 5. Now the voltage across R15
increases and the voltage on the gate of the mosfet also goes up.
The gate-source voltage of the FET decreases and the current
gets lower. The loop is closed.
I already mentioned how to calculate the sense resistor. The other
resistor that has to be tailored to the application is R15. I calculate
this resistor to give a current draw of about 8mA during normal operation
of the circuit. The formula is R15 = (Uin-4V)/8mA
I have successfully used this regulator to feed the filaments of types
6A3, SV572 and 211
Best regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: "Sylvain Giguere" <pagebleu@globetrotter.qc.ca>
Subject: Re: [JN] Manger driver
Date: Mon, 25 Oct 1999 08:29:52 -0400
Source: Sound Digest Archive v02.n314
Hi there,
I have seen and "heard" the Manger driver driver at the Montreal audio show
last spring. One of the most interesting sound at the show. Very coherent,
naturally balanced with 3D imaging. The only drawback seemed to be the
price. The drivers are available separately. Up to now, the only almost full
range driver I've heard that really delivers the goodies, except maybe the
Reps 1. no huge peaks in the treble unlike some famous 8" full range
drivers...
Sylvain Giguère
=========================================================================
From: Gerhard Dierkes <die@magnus.berlin.ptb.de>
Subject: [JN] Manger driver
Date: Mon, 25 Oct 1999 10:04:52 +0200
Source: Sound Digest Archive v02.n314
Hello all,
I have seen a really interesting driver at www.manger-msw.de.
The Manger Schallwandler is a precision point source driver for
full range (80Hz - 30kHz) but has a sensivity 89 db. There is a
rear loaded Horn at www.speaker-online.de/manger.
Has anybody of you experience with this driver and single ended
triode amps?
Thanks in advance
Gerhard Dierkes, Berlin
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Re: Manger driver
Date: Wed, 27 Oct 1999 19:19:59 GMT
Source: Sound Digest Archive v02.n317
Hi there,
I have heard the Manger a few times back in germany. this was the non-SE
version with 84db senstivity.
>The Mangar is not especially an easy unit to use. This driver works
>best at low to moderate listening levels.
Yes, that mirrors my experience. A little like electrostatic Speakers. Very
beautifull if played quietly, can't rock though.
And they need some seriously meaty amplifiers too.... The new version may
have alleviated that somewhat, but probably not enough.
I talked a while back to Daniela Manger about trying the Driver with an ORIS
150 Fronthorn. After categoric insistance that this would not work (why
not?) and after hearing I was out to destroy the good sound of the Manger I
gave up and got some good Lowthers instead.
I have not looked back since....
Ciao Thorsten
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: connlyra@gol.com
Subject: [JN] Re: Manger driver
Date: Thu, 28 Oct 1999 03:32:36 +0900
Source: Sound Digest Archive v02.n317
>I have seen a really interesting driver at http://www.manger-msw.de.
>The Manger Schallwandler is a precision point source driver for full
>range (80Hz - 30kHz) but has a sensivity 89 db. There is a rear
>loaded Horn at www.speaker-online.de/manger. Has anybody of you
>experience with this driver and single ended triode amps?<
Greetings, Gerhard
I have lived with the Mangar unit in the form of the AudioPhysic
Medea, and I have also helped design a 3-way speaker using the Mangar
as the midrange.
The Mangar is not especially an easy unit to use. This driver works
best at low to moderate listening levels. This is especially
noticeable when you use only a single unit. It can sound a bit raw
and congested if you push the SPLs up too much. Also, assuming a
single driver, the LF transition should be somewhere between 120 -
150Hz. 80Hz will make everything muddier, and it will sound
distressed at an even lower listening level than it normally does.
If you don't stress it too much, the Mangar has a very coherent,
natural sound. If anything, it normally sounds a bit "dark", although
my impression is that this occurs more as a result of low distortion
than a rolled-off treble. The character is more relaxed than exciting
(compared to something like, say, the Crosby MkII or Mk III modified
ESL-63s). Imaging and soundstaging in the mid-band are _very_ good.
Not only are images precisely placed within the soundstage, but they
feel like they are 3-dimensional rounded sculptures, rather than 2-D
bas reliefs. Everything "floats" in a organic, almost dreamlike
fashion. Treble imaging is a bit blurred, as though there may be some
phase problems in the very top octave. The Mangar benefits from
adding a super-tweeter, although there aren't too many that blend in
well.
The tweeters that we tried and worked well include the ATR ion horns
and the "diamond graphite" design used on Panasonic's top-model
speaker.
The Mangar works well with various forms of amplification, including
FM Acoustics, the Tact "digital amplifier", and the GlassMaster (a
6C-33B SEPP design with 300Bs as the driver).
best
jonathan c
=========================================================================
From: Peter Sikking <guigurus@xs4all.nl>
Subject: Re: [JN] Re: Manger driver
Date: Thu, 28 Oct 1999 12:09:22 +0100
Source: Sound Digest Archive v02.n317
jonathan c wrote:
> The Mangar works well with various forms of amplification, including
> FM Acoustics, the Tact "digital amplifier", and the GlassMaster (a
> 6C-33B SEPP design with 300Bs as the driver).
How are the two grids of the 6C-33B's driven by the 300B?
I have a Philips EL86 SEPP sitting here waiting for a solution.
The only sound way I can devise at the moment is a interstage trafo with
two independant secundaries (say, Tango NC-14).
Tried and rejected oodles of SRPP variants (yuck!)
Thanks,
--Peter
: music lover : ultra-fi builder : ui & oo designer & developer : on drums...
: from:amsterdam@berlin : +49 173 800 60 37 : facsimile +49 30 390 94 300
=========================================================================
From: connlyra@gol.com
Subject: [JN] Re: Manger driver
Date: Thu, 28 Oct 1999 22:58:13 +0900
Source: Sound Digest Archive v02.n317
Peter Sikking <guigurus@xs4all.nl> wrote:
>>The Mangar works well with various forms of amplification,
>>including the GlassMaster (a 6C-33B SEPP design with 300Bs as the
>>driver).<<
>How are the two grids of the 6C-33B's driven by the 300B? I have a
>Philips EL86 SEPP sitting here waiting for a solution.<
Hello Peter
Unfortunately I cannot tell you, as the GlassMaster is a commercial
design that belongs to another person, and I would most certainly
destroy a friendship (and likely place myself in legal jeopardy) were
I to do so.
However, I do know that it has been covered at length in a previous
issue of "Tube Kingdom", published by Stereo Sound in Japan. It looks
like a glass and steel computer mini-tower that runs on tubes ("WE
inside") - g
Sorry I cannot be of more assistance.
respectfully yours
jc
=========================================================================
From: Gerhard Dierkes <die@magnus.berlin.ptb.de>
Subject: [JN] Manger driver
Date: Mon, 1 Nov 1999 07:52:47 +0100
Source: Sound Digest Archive v02.n318
Hello all,
thanks for the helpful answers about this subject.
Gerhard
=========================================================================
From: Gerhard Dierkes <die@magnus.berlin.ptb.de>
Subject: [JN] Manger driver
Date: Mon, 1 Nov 1999 08:20:10 +0100
Source: Sound Digest Archive v02.n318
Hello all,
thanks for your helpful answers about this subject.
Gerhard
=========================================================================
From: bill gardner <wg44929@navix.net>
Subject: [JN] manger drivers
Date: Wed, 17 Feb 1999 08:13:45 -0600
Source: Sound Digest Archive v02.n047
Hi All : A friend just purchased a pair of drivers made in Germany that are
unusual and very interesting . He said he did a quick listen using the
Slagle clip test ..... thanks Dave I have also acquired a few hundred gator
clips also . Eric said these things are like nothing he has listened to .
Check out www.//techmdb.com .
later and best Bill Gardner
=========================================================================
From: Torsten.Loesch@enhar-ha.nthames.nhs.uk
Subject: Re: [JN] manger drivers
Date: 17 Feb 1999 14:38:55 +0000
Source: Sound Digest Archive v02.n047
Hi there,
> Hi All : A friend just purchased a pair of drivers made in Germany that are
> unusual and very interesting . He said he did a quick listen using the
> Slagle clip test ..... thanks Dave I have also acquired a few hundred gator
> clips also . Eric said these things are like nothing he has listened to .
> Check out www.//techmdb.com .
And because this is the Joe-net, here is the suitable Horn for this Driver.
But beware, efficiency is low. The Nedymium Magnet Version will do 90db/W,
the (cheaper) normal one will do 84db/W....
http://www.speaker-online.de/manger/
Later Thorsten
=========================================================================
From: darmah@goodnet.com
Subject: Re: [JN] manger drivers
Date: Wed, 17 Feb 1999 12:37:03 -0700
Source: Sound Digest Archive v02.n048
Hi All:
Couldn't quite get the link to work.
Nonetheles I've known about Manger "Wandler" as they are called
in Germany for many years.
They are known for exceptional transient response and low
distortion.
Aspecial type of cone is drive via a standard voice coil but in such
a fashion that it becomes a driving "ring".
There are no resonances in the cone as theseare absorbed in the
surround area.
Very similar in some ways to the wonderfull Jordan units.
The probelm with Mangers has always been low efficiency.
I recall talking about the Manger Wandler with a German
"Tonmeister" many years ago when in on a visit to a recording
studio. I mentioned the very poor efficiency to which he said:
"Who cares...I'll just pump 400 Watts into it. Power is cheap these
days"
Oh well I guess that'll work to som extent as well...now lets see
just how many 300 B' would it take for 400 Watts
Has the efficiency improved with the drivers your friend purchased.
Best Regards
Marc S. Wauters
darmah@goodnet.com
My Lowther Enthusiasts Page:
http://www.goodnet.com/~darmah/lowther/lowther.htm
=========================================================================
From: "pagebleu" <pagebleu@globetrotter.qc.ca>
Subject: [JN] Manger drivers
Date: Wed, 17 Feb 1999 23:03:04 -0500
Source: Sound Digest Archive v02.n048
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Hi folks,
I've found a small error in the url published here about the Manger =
drivers. The adress is: www.techmdb.com
This one works
Sylvain
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<META content=3Dtext/html;charset=3Diso-8859-1 =
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<STYLE></STYLE>
<META content=3D'"MSHTML 5.00.0910.1309"' name=3DGENERATOR></HEAD>
<BODY bgColor=3D#ffffff>
<DIV>Hi folks,</DIV>
<DIV> </DIV>
<DIV>I've found a small error in the url published here about the Manger =
drivers. The adress is: <A=20
href=3D"http://www.techmdb.com">www.techmdb.com</A></DIV>
<DIV> </DIV>
<DIV>This one works</DIV>
<DIV> </DIV>
<DIV>Sylvain</DIV></BODY></HTML>
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=========================================================================
From: bill gardner <wg44929@navix.net>
Subject: Re: [JN] manger drivers
Date: Thu, 18 Feb 1999 09:01:35 -0600
Source: Sound Digest Archive v02.n049
At 02:38 PM 2/17/99 +0000, Torsten.Loesch@enhar-ha.nthames.nhs.uk wrote:
>Hi there,
>
>> Hi All : A friend just purchased a pair of drivers made in Germany that are
>> unusual and very interesting . He said he did a quick listen using the
>> Slagle clip test ..... thanks Dave I have also acquired a few hundred gator
>> clips also . Eric said these things are like nothing he has listened to .
>> Check out www.//techmdb.com .
>
>And because this is the Joe-net, here is the suitable Horn for this Driver.
>But beware, efficiency is low. The Nedymium Magnet Version will do 90db/W,
>the (cheaper) normal one will do 84db/W....
>
>http://www.speaker-online.de/manger/
>
>Later Thorsten
>---------------------------------------------------------------------------
- ------------------------------------
Thanks Thorsten I didn't realize these drivers have been around for so long
. Have you listened to them .....
what kind of ( sound ) animals are they ...... theres a full page ad in
speaker builder , they look like they fell off a flying saucer . Thanks and
peace Bill Gardner
=========================================================================
From: Torsten.Loesch@enhar-ha.nthames.nhs.uk
Subject: Re(2): [JN] manger drivers
Date: 18 Feb 1999 15:08:25 +0000
Source: Sound Digest Archive v02.n049
Hi there,
> Thanks Thorsten I didn't realize these drivers have been around for so long
Well, a few years....
> . Have you listened to them .....
A long time ago. A really long time ago. And than it was the 84db sensitive
Version in some Studio-Monitor.
I felt they where some of the better "full-range" Drivers I ever heard....
But I really can't say anything more from memory....
> what kind of ( sound ) animals are they ......
Bending Wave Transducers. Very clever design actually. There is some more
detail on the Manger Web-site, but it's all in german....
> theres a full page ad in speaker builder ,
> they look like they fell off a flying saucer
They did. Joseph Manger is a Space-Alien - didn't you know? ;-)
Actually they are very smart designed. Now if only Mr. Manger could make them
99db/W....
Later Thorsten
=========================================================================
From: steven <stevensl@mindspring.net>
Subject: Re: Re(2): [JN] manger drivers
Date: Thu, 18 Feb 1999 11:39:09 -0500 (EST)
Source: Sound Digest Archive v02.n050
German is not a problem
check out http://babelfish.altavista.digital.com
it can translate German to English
not perfect but hey.. what more can ya want..
On 18 Feb 1999 Torsten.Loesch@enhar-ha.nthames.nhs.uk wrote:
> Hi there,
>
> > Thanks Thorsten I didn't realize these drivers have been around for so long
>
> Well, a few years....
>
> > . Have you listened to them .....
>
> A long time ago. A really long time ago. And than it was the 84db sensitive
> Version in some Studio-Monitor.
>
> I felt they where some of the better "full-range" Drivers I ever heard....
> But I really can't say anything more from memory....
>
> > what kind of ( sound ) animals are they ......
>
> Bending Wave Transducers. Very clever design actually. There is some more
> detail on the Manger Web-site, but it's all in german....
>
> > theres a full page ad in speaker builder ,
> > they look like they fell off a flying saucer
>
> They did. Joseph Manger is a Space-Alien - didn't you know? ;-)
>
> Actually they are very smart designed. Now if only Mr. Manger could make them
> 99db/W....
>
> Later Thorsten
>
=========================================================================
From: Torsten.Loesch@enhar-ha.nthames.nhs.uk
Subject: Re(2): Re(2): [JN] manger drivers
Date: 18 Feb 1999 16:55:39 +0000
Source: Sound Digest Archive v02.n050
Hi there,
> German is not a problem
Indeed. I speak it fluently (grew up there).... ;-)
> check out http://babelfish.altavista.digital.com
>
> it can translate German to English
Sorry, as native German Speaker I take exception to that.
I allways thought the dubbed over (in the US) Soundtracks on German Films
where horrible.... I was wrong....
Ciao Thorsten
=========================================================================
From: Hartmut Quaschik <Hartmut.Quaschik@munich.netsurf.de>
Subject: Re: [JN] manger drivers
Date: Thu, 18 Feb 1999 22:19:39 +0100
Source: Sound Digest Archive v02.n050
Bill,
I visited the website, and found astonishingly that prices are very near to
German prices.
They are very smooth and clean, electrostat like, but sometimes I miss a
certain
impact or energy. If you listen to classical music, this could be the right
speaker
for you. It may go very loud, yes, I had listened to demoes in large university
auditoriums where they produced the sound of church bells in full level.
Character is polite and smooth, indeed.
regards,
hartmut from Munich
bill gardner schrieb:
> Hi All : A friend just purchased a pair of drivers made in Germany that are
> unusual and very interesting . He said he did a quick listen using the
> Slagle clip test ..... thanks Dave I have also acquired a few hundred gator
> clips also . Eric said these things are like nothing he has listened to .
> Check out www.//techmdb.com .
> later and best Bill Gardner
=========================================================================
From: Hartmut Quaschik <Hartmut.Quaschik@munich.netsurf.de>
Subject: Re: [JN] manger drivers
Date: Thu, 18 Feb 1999 22:23:24 +0100
Source: Sound Digest Archive v02.n050
Thorsten, Joes,
The official German website - partly under construction -
can be seen under:
http://www.manger-msw.com/
and it is in English, too - choose the language flag on the start page.
regards,
hartmut from Munich
Torsten.Loesch@enhar-ha.nthames.nhs.uk schrieb:
> Hi there,
>
> > Hi All : A friend just purchased a pair of drivers made in Germany that are
> > unusual and very interesting . He said he did a quick listen using the
> > Slagle clip test ..... thanks Dave I have also acquired a few hundred gator
> > clips also . Eric said these things are like nothing he has listened to .
> > Check out www.//techmdb.com .
>
> And because this is the Joe-net, here is the suitable Horn for this Driver.
> But beware, efficiency is low. The Nedymium Magnet Version will do 90db/W,
> the (cheaper) normal one will do 84db/W....
>
> http://www.speaker-online.de/manger/
>
> Later Thorsten
=========================================================================
From: steven <stevensl@mindspring.net>
Subject: Re: Re(2): Re(2): [JN] manger drivers
Date: Thu, 18 Feb 1999 19:19:32 -0500 (EST)
Source: Sound Digest Archive v02.n051
> > German is not a problem
>
> Indeed. I speak it fluently (grew up there).... ;-)
>
Considering my german comes from episodes of Hogans Heros
and too many trips to october fest i, sadly to say
am quite lacking in that department.
> > check out http://babelfish.altavista.digital.com
> >
> > it can translate German to English
>
> Sorry, as native German Speaker I take exception to that.
>
sorry but notice i said it CAN translate.. i never said it did a
good job ;-)
> I allways thought the dubbed over (in the US) Soundtracks on German Films
> where horrible.... I was wrong....
I tend to agree.. my favorite film is Das Boot. The English Dub is beyond
horrible. I prefer the german version with english subtitles!
cheers
steven
=========================================================================
From: KevinC927@aol.com
Subject: Re: [JN] manger drivers
Date: Mon, 22 Feb 1999 20:16:12 EST
Source: Sound Digest Archive v02.n056
In a message dated 2/18/99 16:26:16, Hartmut.Quaschik@munich.netsurf.de
writes:
>http://www.manger-msw.com/
>
>and it is in English, too - choose the language flag on the start page.
The English language flag appears not to work. My German is passable, but
Englisch would be preferable.
Kevin Carter
=========================================================================
From: "pagebleu" <pagebleu@globetrotter.qc.ca>
Subject: [JN] Manger products in Montreal audio show
Date: Thu, 18 Feb 1999 11:55:21 -0500
Source: Sound Digest Archive v02.n050
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Hi there,
Just got the info from Manger's distributor in Canada that they'll =
demonstrate their products at the Montreal audio show, march 19th -21st =
at the Delta hotel, room 216.
The distributor's site is in english and contains the info about Manger
www.techmdb.com
Sylvain Gigu=E8re
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<BODY bgColor=3D#ffffff>
<DIV>Hi there,</DIV>
<DIV> </DIV>
<DIV>Just got the info from Manger's distributor in Canada that they'll=20
demonstrate their products at the Montreal audio show, march 19th -21st =
at the=20
Delta hotel, room 216.</DIV>
<DIV> </DIV>
<DIV>The distributor's site is in english and contains the info about=20
Manger</DIV>
<DIV> </DIV>
<DIV><A href=3D"http://www.techmdb.com">www.techmdb.com</A></DIV>
<DIV> </DIV>
<DIV>Sylvain Gigu=E8re</DIV></BODY></HTML>
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=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: [JN] manuals
Date: Thu, 13 May 1999 19:15:05 -0400
Source: Sound Digest Archive v02.n143
Joes,
I've just acquired a Tek 310A 'scope, Heathkit IP-17 tube PS, and a couple
of old Lambda 71 PS. None had the manual. Does anyone know where I could
get copies? Will pay postage and copying costs. Thanks.
Phil
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: [JN] MANUALS FOR HEWLETT PACKARD
Date: Mon, 30 Aug 1999 15:47:09 +0300
Source: Sound Digest Archive v02.n267
DearJoes.
I do need the service and user manual for the HP 302A wave analyzer.
And also a scematic for a HP 712B , regulated power supply.
In fact I also need the scematic for a English reg.PSU.
This has the weirdest name "All power transformer ltd"
model 504.
I will really appreciate any help.
- - Thanks a lot.
Sincerely
- - Kurt Steffensen
=========================================================================
From: SBench@aol.com
Subject: Re: [JN] MANUALS FOR HEWLETT PACKARD
Date: Mon, 30 Aug 1999 20:59:05 EDT
Source: Sound Digest Archive v02.n268
In a message dated 99-08-30 09:53:24 EDT, kurt-steffensen@teliamail.dk writes:
<< DearJoes.
I do need the service and user manual for the HP 302A wave analyzer.
And also a scematic for a HP 712B , regulated power supply.
In fact I also need the scematic for a English reg.PSU.
This has the weirdest name "All power transformer ltd"
model 504.
I will really appreciate any help. >>
Hi Kurt,
Try the following...
Ed Matsuda
Test Equipment Manuals
P.O. Box 390613
San Diego, CA 92149
Tel: 1-619-479-0225
Fax: 1-619-479-1670
"He Sells HP and Tek Manuals"
Best Regards,
Steve
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: Re: [JN] MANUALS FOR HEWLETT PACKARD
Date: Mon, 30 Aug 1999 23:48:24 -0600
Source: Sound Digest Archive v02.n268
Hi Kurt,
Try the following...
Ed Matsuda
Test Equipment Manuals
P.O. Box 390613
San Diego, CA 92149
Tel: 1-619-479-0225
Fax: 1-619-479-1670
"He Sells HP and Tek Manuals"
Best Regards,
Steve
================================
Yo Kurt:
Try as well:
Manuals Plus
P.O. Box 549, TAD #610
Tooele, Ut
84074
1 801 882 7195 Fax
=================
Try also Dean Kidd 1 503 625 7363 Phone
=================
Happy Trails,
Bill - PEARL, Inc.
=========================================================================
From: Matthew White <mtw@vne.net>
Subject: [JN] many thanks
Date: Fri, 11 Aug 2000 18:57:55 -0400
Source: Sound Digest Archive v02.n625
Many thanks to all who responded to my "newbie questions". I now have
more reading materials, kit references, and offers for help than I know
what to do with...
thanks!!!
- -mtw
=========================================================================
From: "Epstein, Jeremy" <JEpstein@ndbcap.com>
Subject: [JN] Mapleshade Vinyl - longish
Date: Wed, 29 Nov 2000 16:02:41 -0500
Source: Sound Digest Archive v02.n748
Hi gang, this one is of interest mostly to vinyl lovers, digi-fans can skip
it.
There is an audiophile label, Mapleshade, which has an interesting, eclectic
catalog of blues, jazz, country, reggae and other CD's.
Steve Zettel has had some correspondence with the owner and is trying to
persuade him to consider vinyl releases of some of his titles. Steve was
discussing this with the Phonogram mailing list and I thought that the wider
whacko community (you know who you are) should be drummed into service to
encourage Pierre to do this.
If you think you would buy a Mapleshade vinyl issue, write to Pierre and
tell him which one. If you are willing to commit to a pre-release pre-order,
tell him that too. Pierre's address is:
pierre@mapleshaderecords.com
Look at www.mapleshaderecords.com for more info on the label.
Mapleshade's reply to Steve follows.
- -j
=====
Date: Wed, 29 Nov 2000 12:33:35 -0700
From: Steve Zettel <zettel@libby.org>
Subject: Reply from Mapleshade
Hi, Phonogrammers
This just in from Eldon at Mapleshade (Pierre's direct e-mail address at
bottom):
Thanks for the leg work and effort you've put forth. Pierre and I are both
VERY big vinyl enthusiasts. Personally, I purchase 20 to 30 LPs a month.
I'm a jazz and blues convert, coming from (and still very much in love with)
punk. Fortunately, there is still a substantial quantity of new, used and
reissued punk vinyl out there.
For a while we were actively polling out customers to gauge their interest
in vinyl. It seems like interest in the prospect of Mapleshade LPs has
dropped off as the new digital formats have debuted over the last few years.
I know Pierre's main reservation thus far has been financial. (i.e. Can we
sell enough records so that he doesn't lose the shirt off his back?) Having
spoken with several other companies that deal with vinyl (both labels and
mail order/distributors), we've been given similar info. It's really tough
to sell LPs unless it's a new recording from a famous/established artist or
a reissue of a famous album. That advice raises very serious concerns for
us, as I'm sure you can appreciate. Our musicians are world-class, but
generally aren't well-known. I'm guessing that direct e-mail correspondence
from people interested in LPs AND our music would go a long way toward
persuading Pierre to revisit the possibility of pressing LPs.
Pierre's direct email address is pierre@mapleshaderecords.com . I've
forwarded both of your messages to him.
Eldon
So, there are some very valid concerns there, but the door is not closed. Up
to you all to write your most persuasive letters to Pierre, and then follow
up from time to time.
Jeremy E: now would be a good time to "let loose the hounds" on Teres,
Analogue Addicts, the Joe-list, and with Doc Bottlehead, or whoever else you
can think of!
Best regards to all,
Steve Z
near Groundswell, MT USA
PS: I can forward a copy of the e-mail I sent Mapleshade, but I don't want
to waste the bandwidth gratuitously, if there isn't any interest.
=========================================
Jeremy Epstein........jepstein@ndbcap.com
800 435 1240..........NDB Capital Markets
=========================================
=========================================================================
From: cgooch@jarl.cs.uop.edu
Subject: [JN] Marantz 240
Date: Sat, 2 Oct 1999 12:33:28 -0700 (PDT)
Source: Sound Digest Archive v02.n291
Black case 125WPC very good condition piece of 70's FI. 200. Please pickup
only.... I home someone is near Sacramento I don't want anymore ups
nightmares thanks.
CAry
=========================================================================
From: cgooch@jarl.cs.uop.edu
Subject: [JN] Marantz 240 on ebay
Date: Wed, 1 Dec 1999 23:48:28 -0800 (PST)
Source: Sound Digest Archive v02.n350
Item #210409574
thanks.
Cary
=========================================================================
From: cgooch@jarl.cs.uop.edu
Subject: [JN] Marantz 240 power amp
Date: Sun, 10 Oct 1999 18:50:21 -0700 (PDT)
Source: Sound Digest Archive v02.n298
Marantz Model 240 Stereo Power Amplifier
Item #173823791
Classic 70's FI, 3 hours left on ebay.
=========================================================================
From: Randy Cook <randycook@mindspring.com>
Subject: [JN] Marantz 7T Article
Date: Mon, 10 Apr 2000 19:23:49 -0700
Source: Sound Digest Archive v02.n517
Hi all
I am new to this list, and enjoy it so far. I have a request for help.
I am looking for an article that was in Audio Amateur magazine sometime in
the early eighties about updating Marantz 7T preamp. Any other articles or
suggestions on updating this preamp would be welcome.
Thanks
Randy
=========================================================================
From: ALEXSCIFI@aol.com
Subject: Re: [JN] Marantz 7T Article
Date: Tue, 11 Apr 2000 04:36:22 EDT
Source: Sound Digest Archive v02.n517
Check out Volume 8, No. 3 of Positive Feedback--article by Charle Hollander
on 7T:
Back To The Future: Poogeing The 7T Preamp page 49
Alex
=========================================================================
From: "Gary E. Kaufman" <gkaufman@bu.edu>
Subject: [JN] Marantz CC38
Date: Wed, 11 Apr 2001 20:37:05 -0400
Source: Sound Digest Archive v02.n865
Tonights roadside pickup was a Marantz CC38 which loads disks fine, but
won't spin up.
Anyone have repair hints or a manual?
Thanks!
- Gary
Web: http://www.the-planet.org
Email: gkaufman@the-planet.org
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Marantz CC38
Date: Thu, 12 Apr 2001 18:36:44 +0200
Source: Sound Digest Archive v02.n865
Hi Gary
This link may help:
http://www.bithose.com/serfaq/REPAIR/F_cdfaq.html
Guido
At 20:37 11-4-01 -0400, Gary E. Kaufman wrote:
>Tonights roadside pickup was a Marantz CC38 which loads disks fine, but
>won't spin up.
>
>Anyone have repair hints or a manual?
>
>Thanks!
>
> - Gary
>
>Web: http://www.the-planet.org
>Email: gkaufman@the-planet.org
=========================================================================
From: Remco Stoutjesdijk <remco@ultranalog.com>
Subject: Re: [JN] Marantz CC38
Date: Fri, 13 Apr 2001 00:24:40 +0200
Source: Sound Digest Archive v02.n866
> Tonights roadside pickup was a Marantz CC38 which loads disks fine, but
> won't spin up.
>
> Anyone have repair hints or a manual?
Sounds like the eternal CDM-12 problem: drawer closes, but transport
doens't come up to full height. Check the springs / grease on the
sliding mechanism. Or just throw it away.
Remco
- --
http://www.ultranalog.com
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] Marantz CD-63SE gown?
Date: Thu, 30 Nov 2000 18:51:41 EST
Source: Sound Digest Archive v02.n749
- --part1_52.40e3dee.2758420d_boundary
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
In a message dated 11/30/00 11:41:30 AM US Mountain Standard Time,
rchamber@norwich.edu writes:
> what year the Marantz CD-63SE came out?
>
... and does anyone remember what she wore?
Al B^}
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Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>In a message dated 11/30/00 1
1:41:30 AM US Mountain Standard Time, <BR>rchamber@norwich.edu writes:
<BR>
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px
; PADDING-LEFT: 5px">what year the Marantz CD-63SE came out?
<BR></BLOCKQUOTE>
<BR>
<BR>... and does anyone remember what she wore?
<BR>
<BR>Al B^}
<BR>
<BR></FONT></HTML>
- --part1_52.40e3dee.2758420d_boundary--
=========================================================================
From: Robert C Chambers <rchamber@norwich.edu>
Subject: [JN] Marantz CD-63SE Vintage
Date: Thu, 30 Nov 2000 13:36:23 -0500 (EST)
Source: Sound Digest Archive v02.n749
Joes-
Does anyone know what year the Marantz CD-63SE came out?
Thanks and Regards,
Robert
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: Re: [JN] Marantz CD-63SE Vintage
Date: Thu, 30 Nov 2000 23:55:55 -0500
Source: Sound Digest Archive v02.n749
I think it was late 1995,early 1996. My unit, which I got from Joe
Roberts (he got hold of one to test) was made in Feb 1996.
Thanks, Steve
Robert C Chambers wrote:
> Joes-
>
> Does anyone know what year the Marantz CD-63SE came out?
>
> Thanks and Regards,
>
> Robert
=========================================================================
From: "Ed Coleman" <ecoleman@whidbey.net>
Subject: [JN] Marantz cd player?
Date: Thu, 9 Mar 2000 16:14:37 -0800
Source: Sound Digest Archive v02.n477
Hey Joes, I'm looking to buy a cheap(er) used cd player,and have been told
the Marantz se63 or se67 is the one to go for .Any recommendations of one or
the other? any leads? TIA Ed
=========================================================================
From: "Phil Sieg" <psieg@nxs.net>
Subject: [JN] Re: Marcel_Clovis PP45 Amplifier
Date: Sun, 17 Dec 2000 10:46:21 -0500
Source: Sound Digest Archive v02.n761
Hi Andrej,
>
> Thanks for sharing the schematics of your new amps with us. They are very
> interesting to me and if you say you are flabbergasted by the results,
well,
> they must be something special, sonically.
You flatter me, but I do think they are quite special. And credit where
due, I was just the technician. Inspiration came from the Ancient Texts (if
I can be pardoned a bit of hyperbole), Sakuma-san and Lynn Olson's Amity
amps.
>
> Could you perhaps let us know what is sonically the difference between
these and
> your earlier parallel feed SE 45 amp?
In all fairness to my direct-coupled parafeed 45, these amps at a nominal 3W
showed how much the T-1s were pushing the parafeed 45s to the limit. Much
better dynamics with the new amps, but also much greater ease of
presentation. Less in the way, if you will. We were listening to
Schnabel's 1934 Waldstein last evening and I was struck by the clarity of
the piano, how much it sounded like a real piano. I find this extraordinary
in that this was a transfer from 78s of a 66-year-old recording.
To continue with the piano theme, a lot of '50s era jazz has always had a
somewhat muffled sounding rhythm section to my ears. With these amps
that's, by and large, gone. More of a "club atmosphere", if you will. More
clarity (that word again) between instruments, more tonally correct,
improved low level detail on both attack and decay.
Even 3W are pushed on the Layton/Mohr Shaded Dog of Puccini's Turandot
(Nillson, Tebaldi, Bjoerling, Tozzi, Rome Opera Orchestra &
chorus/Leinsdorf). But the massed choruses cheering the Unknown Prince can
swell to higher levels before things start breaking up.
So I plan to rebuild my 45s in a similar topology as midrange amps and add a
71A tweeter amp, again of similar topology. That will be about 5 glorious W
and a definite contender for lbs/W champeen ;-).
>
> I am also curious about the IT transfomer, which you're using in your new
amps
> - EXO-31, nickel core, 5K:20K, Magnequest transformer. Who sells them and
what
> is their price?
They appeared briefy on the Valve page last spring. They were $300/pair.
AFAIK, there are only 3 pairs currently in existence. there were some
inquiries on the Bottlehead Forum and I believe Mike said he will will
still make them on custom order.
Best,
Phil
>
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: [JN] Marchand Crossover Finished
Date: Sun, 26 Nov 2000 23:50:12 -0500
Source: Sound Digest Archive v02.n746
Well, I got my crossover finished tonight. I hooked it up (low and
midrange) and so far I have mixed feelings. There was a definite
improvement in the bass, but much of this was due to the fact that the
bass was coming from VMPS subwoofers (good up to 600Hz). The midrange
(running thru my 300B amps and coming out my horns) was much more shrill
and glaring (in my initial impression). My crossover points were 300Hz
and 6000Hz, so my horns were not doing anything high. I have not
connected up my JBL tweets yet.
I've got much more tweaking to do. I was driving the subs with a 300W
Heath power amp.
Later, I'm going to try having the Heath power my regular woofers and
the subs off the lowpass from the crossover and just add a coil inline
to keep the subs playing just the very low stuff. I'm going to add a
nice little 6BQ5 amp for the JBL 2405 tweets, and continue to let the
300B's power the midrange horns. In effect, this will be a 4-way
system.
=========================================================================
From: "Jon Lane" <jhlane@reflexnet.net>
Subject: RE: [JN] Marchand Crossover Finished
Date: Mon, 27 Nov 2000 07:45:06 -0700
Source: Sound Digest Archive v02.n746
> Well, I got my crossover finished tonight. I
> hooked it up (low and
> midrange) and so far I have mixed feelings.
> There was a definite
> improvement in the bass, but much of this was due
> to the fact that the
> bass was coming from VMPS subwoofers (good up to
> 600Hz). The midrange
> (running thru my 300B amps and coming out my
> horns) was much more shrill
> and glaring (in my initial impression). My
> crossover points were 300Hz
> and 6000Hz, so my horns were not doing anything
> high. I have not
> connected up my JBL tweets yet.
Did you say this is not Marchand's tube xover?
Unfortunately, as good a value as the sand Marchand is (and
I've used my share in budget theater installs) it is of
course, a generic opamp setup. The fact it did as well as
it did on a horn rig is a testament to its otherwise
excellent engineering.
Two solutions: First, specify the highest-grade audio chips
from Phil. While the stock jobs tend to sound like a
triangular wave generator, the better ones are far easier to
get along with. Second, try Rudi Blondia's excellent
Clearview active crossover. This one is more money but
nearly sonically invisible. www.audio-x-stream.com
Jon Lane
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: RE: [JN] Marchand Crossover Finished
Date: Mon, 27 Nov 2000 08:18:59 -0800
Source: Sound Digest Archive v02.n746
>Second, try Rudi Blondia's excellent
>Clearview active crossover. This one is more money but
>nearly sonically invisible. www.audio-x-stream.com
Unfortuneatly these units are almost impossible to get from Rudy. Some
members of the basslist have been waiting a long time...
dave
__________________________________
"As everybody knows high power amplifiers use larger electrons to achieve
this high power. The bigger electrons don't start or stop as fast as
normal electrons resulting in much heavier, less nimble Watts. So high
power amplifiers can never have the finesse of low power amplifiers. High
sensitivity speakers only work with the smaller electrons (the smallest are
produced by tube amplifiers). Thus if you use a high power amplifier with
sensitive speakers you need a transformer that slims down the electrons and
makes them swifter. Such transformers are available from Jenny Craig Audio
Inc., Phen-Fenophile Corp. and the US Nuclear Agency."
Alan Ross
PS. Don't forget to elevate the amplifiers above the speakers, so the
signal can flow easier.
=========================================================================
From: "Norman Tracy" <ntracy@galstar.com>
Subject: RE: [JN] Marchand Crossover Finished
Date: Mon, 27 Nov 2000 22:24:45 -0600
Source: Sound Digest Archive v02.n747
> Subject: RE: [JN] Marchand Crossover Finished
>
>
> >Second, try Rudi Blondia's excellent
> >Clearview active crossover. This one is more money but
> >nearly sonically invisible. www.audio-x-stream.com
>
> Unfortuneatly these units are almost impossible to get from Rudy. Some
> members of the basslist have been waiting a long time...
>
> dave
Alas I have to agree with the warning off from audio-x-stream. My best
friend has given up on ever seeing the last remaining pieces to get his
crossover finished. Promised ship dates came and went with no parts
arriving. Finally e-mails were no longer answered and the only known phone
numbers went dead. The Marchand may not be as sexy but at least its not
vaporware. Hearing the long story unfold I believe Rudy's intentions were
all for the good but the reality of what one can accomplish juggling life, a
day job, and fledgling audio business where every customer wants something
custom just came crashing down.
Should anyone hear of a Phoenix arising from the ashes let me know so I can
help my buddy get those last pieces.
regards
Norman Tracy
Audio Crafters Guild
5102 E 38 PL
Tulsa OK 74135 USA
918.627.5878 voice
918.481.0970 fax
ntracy@galstar.com e-mail
www.galstar.com/~ntracy/acg URL
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: [JN] Marchand Crossover - who's built one?
Date: Thu, 23 Nov 2000 01:55:34 -0500
Source: Sound Digest Archive v02.n744
Who was it that said they had built a Marchand crossover (from kit)?
I'm working on mine (a 3-way XM9), and I have mostly good things to say
so far - pretty good instructions and addendums, good parts packaging
and identification, good heavy chassis, etc.
However, I have come to the point of installing the pots along the front
of the chassis and find that there are no alignment holes for the tabs
to fit into as mentioned in the instructions. Did anyone else run into
this same problem? If so, what was the solution? Drill your own, or
did they send me a defective chassis?
Thanks, Steve
=========================================================================
From: "David R. McGown" <dmcgown@megacats.com>
Subject: Re: [JN] Marchand Crossover - who's built one?
Date: Thu, 23 Nov 2000 08:24:48 -0500 (EST)
Source: Sound Digest Archive v02.n744
I build a Marchand 2-way XM9 kit, and remember that there were no
alignment holes on mine, either. On top of that, the range of arc of the
pot is about 20 degrees more than the markings on the panel, so you have
to make some decision on where you want to align the pot. Having
no alignment hole gives you that flexibility. I
found that if you torque down on the nut securing the pot to the front
panel, that should hold it in place. I never have had mine move.
David
On Thu, 23 Nov 2000, Steve Van Osdell wrote:
> Who was it that said they had built a Marchand crossover (from kit)?
>
> I'm working on mine (a 3-way XM9), and I have mostly good things to say
> so far - pretty good instructions and addendums, good parts packaging
> and identification, good heavy chassis, etc.
>
> However, I have come to the point of installing the pots along the front
> of the chassis and find that there are no alignment holes for the tabs
> to fit into as mentioned in the instructions. Did anyone else run into
> this same problem? If so, what was the solution? Drill your own, or
> did they send me a defective chassis?
>
> Thanks, Steve
>
=========================================================================
From: Robert Schneider <bobschneiderx@mediaone.net>
Subject: Re: [JN] Marchand Crossover - who's built one?
Date: Thu, 23 Nov 2000 14:16:57 -0600
Source: Sound Digest Archive v02.n745
On Thu, 23 Nov 2000 01:55:34 -0500, you wrote:
>Who was it that said they had built a Marchand crossover (from kit)?
>
>I'm working on mine (a 3-way XM9), and I have mostly good things to say
>so far - pretty good instructions and addendums, good parts packaging
>and identification, good heavy chassis, etc.
>
>However, I have come to the point of installing the pots along the front
>of the chassis and find that there are no alignment holes for the tabs
>to fit into as mentioned in the instructions. Did anyone else run into
>this same problem? If so, what was the solution? Drill your own, or
>did they send me a defective chassis?
>
I built a XM-26 about a year ago. I think I had the same problem with
the chassis. If I remember correctly, I drilled alignment holes in
the front panel. Not a big deal, although a small punch and hammer to
put a dent in the center of where each hole goes (like a dimpled
chad!) helps a lot to get the holes aligned properly when you're
drilling.
Right now I'm in the middle of building a custom crossover using
Marchand XM-9 and Bassis modules and a custom power supply, for a B-G
RD-75 ribbon based system. I'm drilling my own chassis for that,
using a Sescom rack mount cabinet (if you need a cabinet, check them
out at www.sescom.com). Now, that's a pain - I'm up to 40 carefully
aligned holes of various sizes, and have yet to do the front panel.
Bob Schneider
bobschneiderx@nospam.mediaone.net
schneirr@nospam.bp.com
The views expressed are not those of my employer, my wife, or
the National Football League.
All rights reserved.
=========================================================================
From: "Bob Greenfield" <Bobg@tdn.net>
Subject: [JN] [jn] Marchand electronics tube x-over
Date: Thu, 21 Jan 1999 11:59:43 -0500
Source: Sound Digest Archive v02.n005
Hi all. I am new to the list and have a question I hope you folks can help
me with.
I am building Lynn Olsen's Ariels. I plan to also to build the stereo pair
of ten inch base units using the Scan Speak drivers he specs out in good
bass. My electronics currently consist of an Adcom GPA 5500 power Mosfet
power amp and a Adcom tuner pre amp. I plan to build the Assemblage ST-40
(EL 34 tube) kit amp from the Parts Connection www.sonicfrontiers.com and
use that to power the Ariels. The Adcom will run the 10" woofers. My
question is- I also plan to build an electronic crossover network from
Marchand Electronics (www.marchandelec.com), I was wondering if I should
purchase the tube version for bi-amping or the solid state. I love the sound
of tubes but I would like to have these woofers put out very tight bass. I
have heard that tube equipment is not very good at handling deep bass, does
this mean that I should go Solid state and have tubes only powering the
ariels or should I buy the tube cross over? Any help or criticism is
welcome.
bobg@tdn.net
Bob Greenfield
=========================================================================
From: "Darl Singh" <darl@ihug.co.nz>
Subject: Re: [JN] [jn] Marchand electronics tube x-over
Date: Fri, 22 Jan 1999 12:25:49 +1300
Source: Sound Digest Archive v02.n006
FWIW, I'm using an XM-9 between (paired) Leak Stereo 20's and a 100 WPC
Class A (no, not a mistype!) SS sub amp.
While it took a while to burn in, I'm now _very_ happy with the sound - and
component quality was very high. Even worked first time!
Talking to Phil M, his opinion at the time was the SS version was
preferable, all else considered.....
If I was repeating it, I'd probably still stay SS: unlike , the difference
between tube and SS in this appears lees important than component, PS
quality etc etc. (#'s of components etc appear similar.....signal path
doesn't apper simplified as is generally found say, preamps).
One possibility here to shorten 'prime' signal path is to try a passive high
pass filter then use the XO to 'blend' the subs in - haven't quite got this
right yet - but it does show promise.
Usual caveats: YMMV etc.......
- -Darl
- -----Original Message-----
From: Bob Greenfield <Bobg@tdn.net>
To: sound@lists.io.com <sound@lists.io.com>
Date: Friday, 22 January 1999 06:47
Subject: [JN] [jn] Marchand electronics tube x-over
>Hi all. I am new to the list and have a question I hope you folks can help
>me with.
>I am building Lynn Olsen's Ariels. I plan to also to build the stereo pair
>of ten inch base units using the Scan Speak drivers he specs out in good
>bass. My electronics currently consist of an Adcom GPA 5500 power Mosfet
>power amp and a Adcom tuner pre amp. I plan to build the Assemblage ST-40
>(EL 34 tube) kit amp from the Parts Connection www.sonicfrontiers.com and
>use that to power the Ariels. The Adcom will run the 10" woofers. My
>question is- I also plan to build an electronic crossover network from
>Marchand Electronics (www.marchandelec.com), I was wondering if I should
>purchase the tube version for bi-amping or the solid state. I love the
sound
>of tubes but I would like to have these woofers put out very tight bass. I
>have heard that tube equipment is not very good at handling deep bass, does
>this mean that I should go Solid state and have tubes only powering the
>ariels or should I buy the tube cross over? Any help or criticism is
>welcome.
>bobg@tdn.net
>Bob Greenfield
>
=========================================================================
From: "Thom Mackris" <tmackris@earthlink.net>
Subject: [JN] Re: Marchand electronics tube x-over
Date: Thu, 21 Jan 1999 20:26:33 -0700
Source: Sound Digest Archive v02.n007
Howdy,
Along these lines, have any Ariel builders gone fully active with their
Ariels? I've been toying with ideas similar to Bob's except to go fully
active with either Phil Marchand's 2-way tube x-over or his 3-way ss
unit. The 3 way would be used in order to add a woofer for below 60 Hz.
I've heard so many good things about his tube unit, but not too much
about his ss unit & the last thing I want to do is muck things up.
Lynn's crossover is such an inspired work, that I don't want to bite off
more than I can chew, although I realize that the crossover problem he
was trying to solve was significantly more difficult due to having to
design around the reactive load of a voice coil.
The challenge here seems to be to separate the impedance compensation
since I suspect that it interacts with the rest of the crossover. The
notch filter for the tweeter shouldn't be a problem.
My thoughts for doing this are:
(1) I have a pair of Welborne Moondog 2A3's which surprisingly, drive my
friend's Ariels reasonably well (I stopped being a headbanger several
years ago).
(2) A Second pair ought to control things very nicely.
(3) One amp per frequency range should present a higher impedance to
each amplifier than one amp staring at all of the drivers in parallel.
(4) Owning Lowthers (and having heard and liked Epos speakers), I've
grown to like the sound of an amplifier directly tied to a driver
without any passive components between the two.
Comments ??
Thom
Date: Thu, 21 Jan 1999 11:59:43 -0500
From: "Bob Greenfield" <Bobg@tdn.net>
Subject: [JN] [jn] Marchand electronics tube x-over
Hi all. I am new to the list and have a question I hope you folks can
help
me with.
I am building Lynn Olsen's Ariels. I plan to also to build the stereo
pair
of ten inch base units using the Scan Speak drivers he specs out in good
bass. My electronics currently consist of an Adcom GPA 5500 power Mosfet
power amp and a Adcom tuner pre amp. I plan to build the Assemblage
ST-40
(EL 34 tube) kit amp from the Parts Connection www.sonicfrontiers.com
and
use that to power the Ariels. The Adcom will run the 10" woofers. My
question is- I also plan to build an electronic crossover network from
Marchand Electronics (www.marchandelec.com), I was wondering if I should
purchase the tube version for bi-amping or the solid state. I love the
sound
of tubes but I would like to have these woofers put out very tight bass.
I
have heard that tube equipment is not very good at handling deep bass,
does
this mean that I should go Solid state and have tubes only powering the
ariels or should I buy the tube cross over? Any help or criticism is
welcome.
bobg@tdn.net
Bob Greenfield
============================================================
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: [JN] Marchand XM126
Date: Fri, 26 Nov 1999 10:35:00 -0800
Source: Sound Digest Archive v02.n346
Does anyone have experience/opinions regarding this xover?
Better alternatives in the same or lower price range?
Regards,
Ken Dangerfield
=========================================================================
From: "jhlane" <jhlane@email.msn.com>
Subject: Re: [JN] Marchand XM126
Date: Fri, 26 Nov 1999 11:14:15 -0800
Source: Sound Digest Archive v02.n346
Is the XM126 a tube or SS unit?
The best sounding SS active box I've ever used is made by Rudi
Blondia of www.audio-x-stream.com. Look for the Clearview xover.
Very sophisticated relative to the Marchand.
Originally developed for high-end DIY planar/woofer lash-ups,
this crossover is far better sounding than any other opamp based
stuff I've used. It's entirely configurable and offers a number
of modular EQ functions should you need 'em.
On the other hand, the best hifi I've ever heard had passive
parts in the balanced 600 ohm line upstream of three sets of amps
in a three-way triamped setup. Like little passive filters
seeing a simple load. Cheap, too.
Jon Lane
- ----- Original Message -----
From: Ken Dangerfield <bpyakd@mail.island.net>
To: <sound@deliverator.io.com>
Sent: Friday, November 26, 1999 10:35 AM
Subject: [JN] Marchand XM126
> Does anyone have experience/opinions regarding this xover?
> Better alternatives in the same or lower price range?
>
> Regards,
> Ken Dangerfield
=========================================================================
From: Craig Preston <cpreston@mediaone.net>
Subject: Re: [JN] Marchand XM126
Date: Fri, 26 Nov 1999 18:45:01 -0500
Source: Sound Digest Archive v02.n346
Jon,
Any idea what Rudi's crossover costs?
Also, do you or anyone else have experience with the digital
crossover/equalizer systems, such as BSS's FDS-36 or JBL's DSC260. Just
wondering...
Craig Preston
jhlane wrote:
>
> Is the XM126 a tube or SS unit?
>
> The best sounding SS active box I've ever used is made by Rudi
> Blondia of www.audio-x-stream.com. Look for the Clearview xover.
> Very sophisticated relative to the Marchand.
>
> Originally developed for high-end DIY planar/woofer lash-ups,
> this crossover is far better sounding than any other opamp based
> stuff I've used. It's entirely configurable and offers a number
> of modular EQ functions should you need 'em.
>
> On the other hand, the best hifi I've ever heard had passive
> parts in the balanced 600 ohm line upstream of three sets of amps
> in a three-way triamped setup. Like little passive filters
> seeing a simple load. Cheap, too.
>
> Jon Lane
>
> ----- Original Message -----
> From: Ken Dangerfield <bpyakd@mail.island.net>
> To: <sound@deliverator.io.com>
> Sent: Friday, November 26, 1999 10:35 AM
> Subject: [JN] Marchand XM126
>
> > Does anyone have experience/opinions regarding this xover?
> > Better alternatives in the same or lower price range?
> >
> > Regards,
> > Ken Dangerfield
=========================================================================
From: "jhlane" <jhlane@email.msn.com>
Subject: Re: [JN] Marchand XM126
Date: Fri, 26 Nov 1999 21:43:44 -0800
Source: Sound Digest Archive v02.n346
Rudi's crossover is quite reasonable - well under a grand IIRC.
You'll need to specify your freq., rate, and any other EQ
functions needed.
I am somewhat familiar with the BSS. Now owned by Harmon Int.,
IINM, it is a GUI-based digital mixer/EQ/xover to put it mildly.
You basically drag and drop whatever you desire and the hardware
box implements your wishes. Fantastic stuff for the advanced lab
or studio, I'd venture.
Jon Lane
- ----- Original Message -----
From: Craig Preston <cpreston@mediaone.net>
To: jhlane <jhlane@email.msn.com>
Cc: Joelist <sound@deliverator.io.com>
Sent: Friday, November 26, 1999 3:45 PM
Subject: Re: [JN] Marchand XM126
> Jon,
>
> Any idea what Rudi's crossover costs?
>
> Also, do you or anyone else have experience with the digital
> crossover/equalizer systems, such as BSS's FDS-36 or JBL's
DSC260. Just
> wondering...
>
> Craig Preston
>
> jhlane wrote:
> >
> > Is the XM126 a tube or SS unit?
> >
> > The best sounding SS active box I've ever used is made by
Rudi
> > Blondia of www.audio-x-stream.com. Look for the Clearview
xover.
> > Very sophisticated relative to the Marchand.
> >
> > Originally developed for high-end DIY planar/woofer lash-ups,
> > this crossover is far better sounding than any other opamp
based
> > stuff I've used. It's entirely configurable and offers a
number
> > of modular EQ functions should you need 'em.
> >
> > On the other hand, the best hifi I've ever heard had passive
> > parts in the balanced 600 ohm line upstream of three sets of
amps
> > in a three-way triamped setup. Like little passive filters
> > seeing a simple load. Cheap, too.
> >
> > Jon Lane
> >
> > ----- Original Message -----
> > From: Ken Dangerfield <bpyakd@mail.island.net>
> > To: <sound@deliverator.io.com>
> > Sent: Friday, November 26, 1999 10:35 AM
> > Subject: [JN] Marchand XM126
> >
> > > Does anyone have experience/opinions regarding this xover?
> > > Better alternatives in the same or lower price range?
> > >
> > > Regards,
> > > Ken Dangerfield
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: Re: [JN] Marchand XM126
Date: Sat, 27 Nov 1999 12:56:22 +0100
Source: Sound Digest Archive v02.n346
I've been using the FDS-355 Omnidrive compact for 18 months now and I'm
very happy with it. Much more than just a crossover and sonically very
neutral. (http://www.bss.co.uk/e_fds.htm)
Christian
Craig Preston wrote:
> Jon,
>
> Any idea what Rudi's crossover costs?
>
> Also, do you or anyone else have experience with the digital
> crossover/equalizer systems, such as BSS's FDS-36 or JBL's DSC260. Just
> wondering...
>
> Craig Preston
>
> jhlane wrote:
> >
> > Is the XM126 a tube or SS unit?
> >
> > The best sounding SS active box I've ever used is made by Rudi
> > Blondia of www.audio-x-stream.com. Look for the Clearview xover.
> > Very sophisticated relative to the Marchand.
> >
> > Originally developed for high-end DIY planar/woofer lash-ups,
> > this crossover is far better sounding than any other opamp based
> > stuff I've used. It's entirely configurable and offers a number
> > of modular EQ functions should you need 'em.
> >
> > On the other hand, the best hifi I've ever heard had passive
> > parts in the balanced 600 ohm line upstream of three sets of amps
> > in a three-way triamped setup. Like little passive filters
> > seeing a simple load. Cheap, too.
> >
> > Jon Lane
> >
> > ----- Original Message -----
> > From: Ken Dangerfield <bpyakd@mail.island.net>
> > To: <sound@deliverator.io.com>
> > Sent: Friday, November 26, 1999 10:35 AM
> > Subject: [JN] Marchand XM126
> >
> > > Does anyone have experience/opinions regarding this xover?
> > > Better alternatives in the same or lower price range?
> > >
> > > Regards,
> > > Ken Dangerfield
- --
Christian Rintelen Konzept und Text
Dufourstrasse 165 CH-8008 Zurich / Switzerland
Voice: +41 1 420 11 55 Fax: +41 1 420 11 57
mailto:rintelen@datacomm.ch
=========================================================================
From: "Norman Tracy" <ntracy@galstar.com>
Subject: RE: [JN] Marchand XM126
Date: Sat, 27 Nov 1999 18:13:34 -0600
Source: Sound Digest Archive v02.n346
Anyone into high end car audio who can comment on this option? Thanks to a
recent inquiry to ACG the Alpine PRA-H400 digital crossover has come to my
attention. Like the Omnidrive and other DSP based digital units we are
seeing pop up in Euro Ultr-fi systems the PRA-H400 does it's frequency
division in the digital domain AND allows digital time correction to align
the drivers outputs in time. Input is digital only, outputs of up to 4
channels of three way! A cursory check on the web yielded a price of $900
which I believe is a fraction of the other digital units coming from the
pro-audio world.
Norman Tracy
Audio Crafters Guild
ntracy@galstar.com
www.galstar.com/~ntracy/acg
918-627-5878
> -----Original Message-----
> From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
> Behalf Of Christian Rintelen
> Sent: Saturday, November 27, 1999 5:56 AM
> To: Joelist
> Subject: Re: [JN] Marchand XM126
>
>
> I've been using the FDS-355 Omnidrive compact for 18 months now and I'm
> very happy with it. Much more than just a crossover and sonically very
> neutral. (http://www.bss.co.uk/e_fds.htm)
> Christian
>
> Craig Preston wrote:
>
> > Jon,
> >
> > Any idea what Rudi's crossover costs?
> >
> > Also, do you or anyone else have experience with the digital
> > crossover/equalizer systems, such as BSS's FDS-36 or JBL's DSC260. Just
> > wondering...
> >
> > Craig Preston
> >
> > jhlane wrote:
> > >
> > > Is the XM126 a tube or SS unit?
> > >
> > > The best sounding SS active box I've ever used is made by Rudi
> > > Blondia of www.audio-x-stream.com. Look for the Clearview xover.
> > > Very sophisticated relative to the Marchand.
> > >
> > > Originally developed for high-end DIY planar/woofer lash-ups,
> > > this crossover is far better sounding than any other opamp based
> > > stuff I've used. It's entirely configurable and offers a number
> > > of modular EQ functions should you need 'em.
> > >
> > > On the other hand, the best hifi I've ever heard had passive
> > > parts in the balanced 600 ohm line upstream of three sets of amps
> > > in a three-way triamped setup. Like little passive filters
> > > seeing a simple load. Cheap, too.
> > >
> > > Jon Lane
> > >
> > > ----- Original Message -----
> > > From: Ken Dangerfield <bpyakd@mail.island.net>
> > > To: <sound@deliverator.io.com>
> > > Sent: Friday, November 26, 1999 10:35 AM
> > > Subject: [JN] Marchand XM126
> > >
> > > > Does anyone have experience/opinions regarding this xover?
> > > > Better alternatives in the same or lower price range?
> > > >
> > > > Regards,
> > > > Ken Dangerfield
>
> --
> Christian Rintelen Konzept und Text
> Dufourstrasse 165 CH-8008 Zurich / Switzerland
> Voice: +41 1 420 11 55 Fax: +41 1 420 11 57
> mailto:rintelen@datacomm.ch
>
>
>
=========================================================================
From: Remco Stoutjesdijk <remco@ultranalog.com>
Subject: [JN] marketplace, gallery
Date: Tue, 01 May 2001 22:37:51 +0200
Source: Sound Digest Archive v02.n877
Hi,
Two ideas came to mind while updating my html.
Wouldn't it be an idea to set up a web forum for joes selling, swapmeeting, trading & buying stuff ?
That way no bandwidth is wasted and folks who don't appreciate the messages won't see 'em.
I've set up such a board as a test at
http://www.ultranalog.com/joemarket/market.html
If it works and finds appreciation, I'll be glad to keep the pages up. I for one like the joe-swap-t
hang ;)
Then another thing: I've made a gallery of pictures of joes I found browsing the web and made a litt
le tribute page at
http://www.ultranalog.com/joenet/joenet.html
Those who don't appreciate their heads being clickable: please let me know, and I'll take it off. Th
ose who want to submit a pic or url can also let me know. The same goes for the list of 'gold' posti
ngs (in progress - there are lots more).
Hope you like it.
Regards,
Remco
- --
http://www.ultranalog.com
=========================================================================
From: Loesch Thorsten <TORSTEN.LOESCH@enhar-ha.nthames.nhs.uk>
Subject: [JN] marketplace, gallery
Date: Wed, 2 May 2001 10:17:11 +0100
Source: Sound Digest Archive v02.n878
Hi,
>Then another thing: I've made a gallery of pictures of joes I found
browsing the web and made a
>little tribute page at http://www.ultranalog.com/joenet/joenet.html
<http://www.ultranalog.com/joenet/joenet.html>
I don't mind being in the "rouges gallery", but don't you think it's
common web courtesy to also link in the website the pictures came from
originally and if any of those included have a website (most do if memory
serves) also include this?
Ciao T
=========================================================================
From: Remco Stoutjesdijk <remco@ultranalog.com>
Subject: Re: [JN] marketplace, gallery
Date: Wed, 02 May 2001 11:40:17 +0200
Source: Sound Digest Archive v02.n878
Hi,
At 11:17 2-5-01, you wrote:
> I don't mind being in the "rouges gallery", but don't you think it's
>common web courtesy to also link in the website the pictures came from
>originally and if any of those included have a website (most do if memory
>serves) also include this?
Point taken, will do. What's the address of yours?
Regards,
Remco
- --
http://www.ultranalog.com
=========================================================================
From: Christian Rintelen <christian@rintelen.ch>
Subject: Re: [JN] marketplace, gallery
Date: Wed, 02 May 2001 12:27:19 +0200
Source: Sound Digest Archive v02.n878
Loesch Thorsten wrote:
> I don't mind being in the "rouges gallery",
rouge?!?
©
=========================================================================
From: Loesch Thorsten <TORSTEN.LOESCH@enhar-ha.nthames.nhs.uk>
Subject: RE: [JN] marketplace, gallery
Date: Thu, 3 May 2001 14:49:32 +0100
Source: Sound Digest Archive v02.n878
Hi,
>Point taken, will do. What's the address of yours?
http://thunderstoneaudio.nav.to <http://thunderstoneaudio.nav.to>
for short
My site is okay to be misiing, but many others have neat sites and
much less exposure than I have.
Ciao T
=========================================================================
From: david johnson <hifidave@mindspring.com>
Subject: [JN] Mark VI
Date: Fri, 08 Oct 1999 12:35:02 -0400
Source: Sound Digest Archive v02.n296
Hello all,
I have aquired 3 Mark VI chassis (no iron!) and was thinking of using the
driver boards for a PP
generic amp project. Would this"over-kill" driver arrangement minumize
distortion? Also-I've
spent two hours on line (didn't know i had so many bookmarks!) looking for
a scham of this amp-
how can i find it , please!
- -hifi
=========================================================================
From: "Miroslav Kubala" <mikubala@swissonline.ch>
Subject: [JN] Mars Animation
Date: Fri, 24 Dec 1999 11:22:22 +0100
Source: Sound Digest Archive v02.n370
Hi
never say to a woman you are comming from Mars
Happy days
wish you
Mirko
www.jurapharmacy.ch
=========================================================================
From: Martin Seddon <mseddon@iinet.net.au>
Subject: Re: [JN] Martin's -acoustic- horn. WAS: Less is more?
Date: Tue, 27 Mar 2001 22:31:13 +0800
Source: Sound Digest Archive v02.n845
Jean-Michel,
>That's really a pity that you live so far from here, I would surely love to
>listen to those beautiful horns you built after using my spreadsheet to
>calculate them.
I will send you a recording ;-). or better a pair of horns.
>Until now I could only listen to some small square mouth prototypes I built
>myself. I'll receive soon I hope a pair of round horns calculated with my
>methode that a friend is currently building here in France, but they are
>smaller than yours.
>
>I hope next year my friend will be able to build some large (1 meter in
>diameter) horns that I can use in the low mid with those new compression
>drivers I just bought: Beyma 850Nd (2inches with a 4 inch coil, titanium
>membrane and neodynium magnet, 115 dB/1watt/1meter).
How will he make them?
I have been thinking about an accurate but quick method of making moulds or
'patterns' for fibreglass horns - so that experimental designs from your
spreadsheet can be economically made in small numbers.
Fibreglass in itself is now a very efficient technique - using a chopper
gun that actually sprays a stream of fibres onto the mould along with the
resin.
The expense and time is in the first mould or 'pattern' from which a
female, and finally a fibreglass plug mould must be taken. I believe that
I can make a power tool jig that will follow a 2D template. The pattern
material would be foam block as used by fibreglassing shops.
The horns themselves would be cheap to make (especially with low Aussie
dollar)- unfortunately shipping cost is high. I very much like your purist
derivation (though I am not qualified to comment). I would love to be the
means of realisation. the female concert announcer floats on air between
the horns.
so much potential out there. All Paul Butterfields rescued children -
looking for a soul mate.
Martin
=========================================================================
From: John Niven <jn@cypress.com>
Subject: Re: [JN] Martin's -acoustic- horn. WAS: Less is more?
Date: Tue, 27 Mar 2001 11:57:31 -0800
Source: Sound Digest Archive v02.n846
Hi Guys!
I recently tried a technique for prototyping horns which has proved very
useful!
I my case I am trying to make a midrange horn (~250Hz to as high as I
can get it), to use with the RS 40-1197. Why? Because I had some from a
sale, they have large magnets, a small light cone, are very available,
with generally good sound. My budget doesn't run to compression drivers
or Lowthers! Others have said "No, No you can't do that!" but I believe
that, with the right profile, some of the benefits of horn loading can
be realized i.e. higher efficiency, directional behavior, highpass
characteristic.
Anyway, the problem was how to experiment easily, since what I wanted to
achieve may not be possible by calculation from current theory.
I went to my local garden center, and bought a large plastic flower urn
(~$9) with a 46cm diameter "mouth". The "length" is about 39cm. I cut a
hole in the bottom of the urn ("throat" = 7.6cm) to match the 40-1197,
then bought boxes of modeling clay from my local art shop (~$9/25lbs).
This is a type of clay which is designed to dry hard in air, but stays
malleable if you keep it covered with plastic.
By stuffing the clay into the urn I have been able to form a variety of
expansion profiles, which I then measure with my RS SPL meter and test
CD.
The results have been very informative. As well as mealy molding the
clay by hand and eye, I have also cutout sheets of MDF with the 2D
profile. These can then be inserted into the urn and rotated by hand to
make quite accurate, smooth circular horns.
I have found that I can get gains of at least 9dB over the bare driver,
can manipulate the freq. resp. in many different ways, but I am having
trouble making a profile that is flat from 250Hz to 10KHz (which I think
is a reasonable goal). I am however, increasingly confident that I can
do it soon (I am 250 -> 6KHz +/-3dB at the moment). Even so, I rather
like the sound it makes (yes, I use my SPL meter and my ears).
When I find that profile, my plan is to fill the clay horn with plaster,
which, when dry and painted, will then be used as a mold for producing
multiple copies - the poor mans Oris ;-)
But what to mold the final items from? I have considered fiberglass but
have no experience of how to do this. My current thought is concrete (my
these will be heavy :-() I'm open to suggestions.
Hope this helps!
John
Martin Seddon wrote:
>
> Jean-Michel,
>
> >That's really a pity that you live so far from here, I would surely love to
> >listen to those beautiful horns you built after using my spreadsheet to
> >calculate them.
>
> I will send you a recording ;-). or better a pair of horns.
>
> >Until now I could only listen to some small square mouth prototypes I built
> >myself. I'll receive soon I hope a pair of round horns calculated with my
> >methode that a friend is currently building here in France, but they are
> >smaller than yours.
> >
> >I hope next year my friend will be able to build some large (1 meter in
> >diameter) horns that I can use in the low mid with those new compression
> >drivers I just bought: Beyma 850Nd (2inches with a 4 inch coil, titanium
> >membrane and neodynium magnet, 115 dB/1watt/1meter).
>
> How will he make them?
>
> I have been thinking about an accurate but quick method of making moulds or
> 'patterns' for fibreglass horns - so that experimental designs from your
> spreadsheet can be economically made in small numbers.
>
> Fibreglass in itself is now a very efficient technique - using a chopper
> gun that actually sprays a stream of fibres onto the mould along with the
> resin.
>
> The expense and time is in the first mould or 'pattern' from which a
> female, and finally a fibreglass plug mould must be taken. I believe that
> I can make a power tool jig that will follow a 2D template. The pattern
> material would be foam block as used by fibreglassing shops.
>
> The horns themselves would be cheap to make (especially with low Aussie
> dollar)- unfortunately shipping cost is high. I very much like your purist
> derivation (though I am not qualified to comment). I would love to be the
> means of realisation. the female concert announcer floats on air between
> the horns.
>
> so much potential out there. All Paul Butterfields rescued children -
> looking for a soul mate.
>
> Martin
=========================================================================
From: "Le Cleac'h Jean-Michel" <lecleach@paris.ensmp.fr>
Subject: [JN] Martin Seddon's horn. WAS: Less is more?
Date: Mon, 26 Mar 2001 17:32:39 +0200
Source: Sound Digest Archive v02.n843
- -----Message d'origine-----
De : Martin Seddon <mseddon@iinet.net.au>
À : sound@lists.io.com <sound@lists.io.com>
Date : lundi 26 mars 2001 17:00
Objet : Re: [JN] Less is more???? Not always!
>This stuff is for real. I finally got Lowther PM2A / front horns rigged up
>with biamped bass. Expansion by Jean-Michel Le Cleac'h made in fibreglass
>- 1m mouth. I am on a real high - I feel right in sinc with list for once.
> Amazing clarity and percussion. But something ... just not right.
> Mick Maloney came round and we focused the array and reversed the
>bass speaker polarity - better. Still amazing.
>But tonight reading the above and what went before (best joenet gets) I got
>up and reversed both the Lowthers - (could easily hear the bass was out of
>phase then) - reversed the bass speakers too - and then it slowly dawned on
me
>depth and warmth - pure @#$!ing deep magic - break on through!
>Anyway warm thanks to Jean-Michel for his inspired spherical wave front
>program (check archives DEC 1999 for discussion of). When I can I will
>post pin ups - LH sky blue / RH pure white - voluptuous.
Dear Martin,
That's really a pity that you live so far from here, I would surely love to
listen to those beautiful horns you built after using my spreadsheet to
calculate them.
Until now I could only listen to some small square mouth prototypes I built
myself. I'll receive soon I hope a pair of round horns calculated with my
methode that a friend is currently building here in France, but they are
smaller than yours.
I hope next year my friend will be able to build some large (1 meter in
diameter) horns that I can use in the low mid with those new compression
drivers I just bought: Beyma 850Nd (2inches with a 4 inch coil, titanium
membrane and neodynium magnet, 115 dB/1watt/1meter).
I am very happy that you appreciate those horns!
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: "Snoopy" <tcma@netvigator.com>
Subject: Re: [JN] Martin Seddon's horn. WAS: Less is more?
Date: Tue, 27 Mar 2001 07:09:42 +0800
Source: Sound Digest Archive v02.n845
Le Cleac'h J.M.,
May I have a copy of your program/spreadsheet in calculating the
spherical wave front? What's the horn flare/expansion? I am very
interested.
Thank you in advance.
Best Regards,
Tung-cheung MA
HONG KONG
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: [JN] Massive email problems
Date: Sat, 04 Dec 1999 12:32:50 -0800
Source: Sound Digest Archive v02.n354
Hi everyone,
I have been away for the past week and a half and have been experiencing
massive email problems since returning. So, if anyone has tried to
contact me over the past two weeks and has not received a reply, please
resend any messages.
AT&T experienced a nationwide email meltsdown on Wednesday morning and
apparently does not yet have all the bugs worked out, though they claim
to have done so. I had 330 messages, most of which downloaded
successfully, except those which came in after their meltdown that same
morning. I have since lost most of them. I am now accessing mail
through webmail, which generally works, but not always. It denied me
this morning, so I downloaded the 41 messages into Netscape which
garbled them and produced massive blank duplications, over six hundred
messages in total. I have contacted AT&T twice and they don't seem to
know what to do about it other than suggesting that I upgrade to
Netscape 4.7 and see what happens. What a pain in the ass this has
turned out to be. Any suggestions?
Dan Marshall
=========================================================================
From: "Mackris, Thom G." <tgmackris@vicorpinc.com>
Subject: RE: [JN] Massive email problems
Date: Sat, 4 Dec 1999 14:48:07 -0700
Source: Sound Digest Archive v02.n354
Hi Dan,
I don't really know if this applies to your problem, but it might. It seems
that one of the benefits of the Netscape / Microsoft war is that Microsoft
reads & converts Netscape's mail better than it reads & converts it's own.
I know that Netscape successfully imports Microsoft's mail, but I'm not sure
if it does a better job of importing Microsoft's mail than it does in
repairing itself. Let me explain ...
A while back, I was running Internet Explorer 4.0 & it's mail package
Outlook Express. When I upgraded to the 5.0 versions, I selected the
"version compatibility option" which allowed me to return to v4.0 if I
decided to uninstall v5.0. This option left my Outlook Express mail files
in 4.0 format.
A while later, I did a rebuild of my hard drive & subsequently restored my
mail and all of my other data files. When I did a fresh install of Internet
Explorer v5.0 (& Outlook Express mail), I was no longer prompted for the
"v4.0 compatibility option" since v4.0 was not installed. After this
install, I could *not* access my mail !!
I solved this by downloading Netscape Communicator v4.6 & importing all of
my Microsoft Outlook Express mail. This was quite readable in Netscape
Communicator after the import, with all of my folder structures intact. I
then imported this Netscape mail back into Outlook Express, and voila - all
the mail was readable & in the new v5.0 format.
Perhaps you can mirror this technique by downloading & installing IE
Explorer v5.0 & Outlook Express, importing your Netscape messages & then
re-importing them into Netscape.
If I can help you any further, feel fee to e-mail ma at my home e-mail (I'm
at work this Saturday but leaving shortly) at:
tmackris@earthlink.net
Cheers,
Thom
- -----Original Message-----
From: Daniel J. Marshall [mailto:danmarshall@worldnet.att.net]
Sent: Saturday, December 04, 1999 1:33 PM
To: sound@io.com
Subject: [JN] Massive email problems
Hi everyone,
I have been away for the past week and a half and have been experiencing
massive email problems since returning. So, if anyone has tried to
contact me over the past two weeks and has not received a reply, please
resend any messages.
AT&T experienced a nationwide email meltsdown on Wednesday morning and
apparently does not yet have all the bugs worked out, though they claim
to have done so. I had 330 messages, most of which downloaded
successfully, except those which came in after their meltdown that same
morning. I have since lost most of them. I am now accessing mail
through webmail, which generally works, but not always. It denied me
this morning, so I downloaded the 41 messages into Netscape which
garbled them and produced massive blank duplications, over six hundred
messages in total. I have contacted AT&T twice and they don't seem to
know what to do about it other than suggesting that I upgrade to
Netscape 4.7 and see what happens. What a pain in the ass this has
turned out to be. Any suggestions?
Dan Marshall
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: [JN] Mass Loaded TQWT
Date: Mon, 23 Apr 2001 21:56:50 -0700
Source: Sound Digest Archive v02.n873
Joes,
Some of you may be familiar with the work Martin King has been doing to
produce a viable model for the transmission line speaker.
He has now extended the range of this model by creating a set of Fostex
FE164 based Tapered Quarter Wave Tubes based on his model. Measurements
verify the efficacy of his model for this TQWT.
<http://www.t-linespeakers.org/projects/martin/MLTQWT/>
His Tube is mass-loaded (much like Bert Doppenberg's dual FE103 tube), and
extends response down to well below 40 Hz. The mass-loading acts as a
filter reducing the comb filtering often attributed to TQWTs.
And this is the 1st DIY article, that i have ever seen anyway, where the
power of ANSYS* has been brought to bear to illustrate one of his points.
* ANSYS is $30k plus finite element analysis software.
dave
____________________________________
Transmission Line Speaker Page
http://www.t-linespeakers.org/
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: [JN] Mastering Lab 604 X-over
Date: Thu, 28 Jan 1999 10:31:48 +0100
Source: Sound Digest Archive v02.n015
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
Joes,
<p>I have published a reengineered schematic of the Mastering Lab 604-crossover
in HiFi Scene some time ago. Let me know when you're interested and I'll
mail a .gif file. (No worries for intellectual property here...)
<p>Christian</html>
=========================================================================
From: David Suess <ds10760@pace.medtronic.com>
Subject: [JN] Matching 2SK147 / 2SK170
Date: Wed, 28 Apr 1999 10:17:01 -0500 (CDT)
Source: Sound Digest Archive v02.n134
Torsten wrote:
> Make sure to MATCH the FET's between channels and select them for about 10mA
> Idss (Allen posted the ciruit do that to the list a while back)....
ack)....
First -- how important is it to match the FET's ???
Second -- When was this circuit posted? I'd like to go to the archives and
find it.
BTW, MCM has the 2SK170 for $0.80/each (if I remember correctly).
thanks,
david suess
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: [JN] Matching 2SK147 / 2SK170
Date: Wed, 28 Apr 1999 13:08:55 -0400
Source: Sound Digest Archive v02.n134
David asked:
>>>First -- how important is it to match the FET's ???<<<
VERY important if you are using them in a diff pair. Still important IMO
when you are using them in SE circuits but want the channels to be really
matched.
>>>Second -- When was this circuit posted? I'd like to go to the archives
and find it<<<
No idea, but it's in my book...
>>>BTW, MCM has the 2SK170 for $0.80/each (if I remember correctly)<<<
Good, as far as I can work out they use the same chip as the 2SK147,
certainly from the same very high transconductance family.
Allen (VSE)
=========================================================================
From: Torsten.Loesch@enhar-ha.nthames.nhs.uk
Subject: Re: [JN] Matching 2SK147 / 2SK170
Date: 28 Apr 1999 18:30:50 +0000
Source: Sound Digest Archive v02.n134
Hi there,
> First -- how important is it to match the FET's ???
Absolutely essential. The Differences in Idss for 8 different 2SK147BL I have
around gave one Pair with 17mA IDss, one Pair with 10mA IDss and four (so
far) useless pieces without any match....
> Second -- When was this circuit posted? I'd like to go to the archives and
> find it.
Allen posted it as Binary, I suspect you'll not find it in the Arcives on the
io.com Server....
Later Thorsten
=========================================================================
From: David Home <DHome@creo.com>
Subject: [JN] matching 2SK170s
Date: Tue, 22 Feb 2000 13:09:49 -0800
Source: Sound Digest Archive v02.n459
Hello Friends. I have measured thirty 2SK170s to come up with a matched pair
to use below the 417A input tube of my SJS 66 dB phono amp. I was lent a jig
by Jeremy to do this which consists of a CCS feeding the source and a 9V
battery on the drain. I measured the 'Difference' between the potential of
the gate and the source.
I used a current of 10ma as Thorsten had advised for this use. I was
surprised by the range of values that I got! I was most surprised that I got
positive and negative values! I hate testing something when I do not really
understand what I exactly am testing.
Is is significant that some FETs gave a positive reading while others gave a
negative one? The range I got was from -234mV to +102mV, with one quad at
100-102ma, and two other pairs at -38mV and -75mV.
Is it only important that they match rather then the value?
Is the positive values more/less desirable then the negative values?
How close do a pair need to be to be useful as a 'matched' pair?
I have quite a few that are within +/-3mV. Anyway I would appreciate any
thoughts on weather the voltage values I got sound reasonable and to confirm
that I did it correctly. Thanks. Regards, David
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: [JN] matching 2SK170s
Date: Tue, 22 Feb 2000 19:38:44 -0500
Source: Sound Digest Archive v02.n459
David asked:
>>>Is is significant that some FETs gave a positive reading while others
gave a
negative one? The range I got was from -234mV to +102mV, with one quad at
100-102ma, and two other pairs at -38mV and -75mV<<<
David, what's happening is that unfortunatly you have some very wide spread
devices there - but this is normal for jfets. The 170 data sheet gives the
range for IDSS as 2 - 20mA...like wow Batman, this is 10 to 1! IDSS being
the current the fet passes when the gate is shorted to the source.
To get the fet to pass more than it's IDSS value you need to drive the gate
positive to the source - just like positive bias on a tube - and this is
the "+" values you have on some of them.
This is not a good operating point for a jfet that you want to operate in a
VERY linear manner right at the front of your signal path, so keep them
aside for something else that will use them at lower currents. I would use
the -75mV pair myself.
>>>Is it only important that they match rather then the value?<<<
No - as above.
>>>Is the positive values more/less desirable then the negative values?<<
The positive (that is gate positive) are - in my experience of doing this
mod for around 15 years now - unusable in your application. Remember that
you have to liftthe grid of the upper cascode tube some 3 to 7 volts above
gnd - Thorsten suggested a 3.6V lithium battery, and I generally use a
LM329 6.9V voltage reference chip
>>>How close do a pair need to be to be useful as a 'matched' pair? I have
quite a few that are within +/-3mV.<<<
This is really good and much better than the expensive "double packaged"
fets that Toshiba sell as matched pairs - they allow 20mV max difference.
Normally this range of fets (2SK147, 170, 369 etc) have a "GR" (green),
"BL" (blue) or "V" (violet) suffex after the part number - eg 2SK170GR or
2SK170BL. These are the IDSS current groups they (can) split the fets up
into after testing at the factory. Or they just ship them out ungrouped. Do
your fets have such a suffex?
For 10mA operating current you could only be certain of correct operation
with the 14 - 20mA IDSS "V" grouping - BL's (8-14mA) you have to check and
GR's (2-8) are not up to it without some positive bias.
Please let us know how it sounds, OK?
Allen (VSE)
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: [JN] matching 2SK170s
Date: Tue, 22 Feb 2000 22:50:40 -0800
Source: Sound Digest Archive v02.n459
Thanks Allen for such a clear reply. My jfets are marked with a 'V', so I
guess they fall in the group that is OK for my use.
Pretty disturbing that I paid for V rating and almost half the units are not
up to the standard. Just shows that it always worthwhile to do your own
checking.
I looked carefully at my jfets and only have an exact match at -38mV. I have
a pair at -80/82 and a pair at -193/199. Is more negative better? Regards,
David
- -----Original Message-----
From: Allen Wright [mailto:AllenVSE@compuserve.com]
Sent: Tuesday, February 22, 2000 4:39 PM
To: David Home; JoeNet A
Subject: [JN] matching 2SK170s
David asked:
>>>Is is significant that some FETs gave a positive reading while others
gave a
negative one? The range I got was from -234mV to +102mV, with one quad at
100-102ma, and two other pairs at -38mV and -75mV<<<
David, what's happening is that unfortunatly you have some very wide spread
devices there - but this is normal for jfets. The 170 data sheet gives the
range for IDSS as 2 - 20mA...like wow Batman, this is 10 to 1! IDSS being
the current the fet passes when the gate is shorted to the source.
To get the fet to pass more than it's IDSS value you need to drive the gate
positive to the source - just like positive bias on a tube - and this is
the "+" values you have on some of them.
This is not a good operating point for a jfet that you want to operate in a
VERY linear manner right at the front of your signal path, so keep them
aside for something else that will use them at lower currents. I would use
the -75mV pair myself.
>>>Is it only important that they match rather then the value?<<<
No - as above.
>>>Is the positive values more/less desirable then the negative values?<<
The positive (that is gate positive) are - in my experience of doing this
mod for around 15 years now - unusable in your application. Remember that
you have to liftthe grid of the upper cascode tube some 3 to 7 volts above
gnd - Thorsten suggested a 3.6V lithium battery, and I generally use a
LM329 6.9V voltage reference chip
>>>How close do a pair need to be to be useful as a 'matched' pair? I have
quite a few that are within +/-3mV.<<<
This is really good and much better than the expensive "double packaged"
fets that Toshiba sell as matched pairs - they allow 20mV max difference.
Normally this range of fets (2SK147, 170, 369 etc) have a "GR" (green),
"BL" (blue) or "V" (violet) suffex after the part number - eg 2SK170GR or
2SK170BL. These are the IDSS current groups they (can) split the fets up
into after testing at the factory. Or they just ship them out ungrouped. Do
your fets have such a suffex?
For 10mA operating current you could only be certain of correct operation
with the 14 - 20mA IDSS "V" grouping - BL's (8-14mA) you have to check and
GR's (2-8) are not up to it without some positive bias.
Please let us know how it sounds, OK?
Allen (VSE)
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: [JN] matching 2SK170s
Date: Tue, 22 Feb 00 17:02:54 -0500
Source: Sound Digest Archive v02.n459
>I used a current of 10ma as Thorsten had advised for this use. I was
>surprised by the range of values that I got!
David,
I used the 2SK147 & 72 in a preamp in the early 80's. I have a transistor
lab and had very wide varience in all the units. I am not surprised by
your results.
They are good sounding units some of the best SS.
Gordon
=====> Wavelength Audio <=====
mailto:waudio@cinti.net
http://www.WavelengthAudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: "Hugh R. Dean" <aspen@alphalink.com.au>
Subject: Re: [JN] matching 2SK170s
Date: Wed, 23 Feb 2000 09:35:52 +1100
Source: Sound Digest Archive v02.n459
Hi David, Jeremy, and Thorsten,
David wrote this:
| Hello Friends. I have measured thirty 2SK170s to come up with a matched
pair
| to use below the 417A input tube of my SJS 66 dB phono amp. I was lent a
jig
| by Jeremy to do this which consists of a CCS feeding the source and a 9V
| battery on the drain. I measured the 'Difference' between the potential of
| the gate and the source.
| I used a current of 10ma as Thorsten had advised for this use.
I'm not sure on this. Please fill me in...
If we use a JFET under a cascoding triode, then it is the JFET which
controls the current, n'est pas?
If the JFET controls the current and we want minimum noise, then we use, as
Jean-Michel has identified, no source resistor. Thus the source and the
gate are tied to the same potential.
Let's say we want, 10mA, then the logical test would be to grab a 6V
battery, hook a mA meter to the positive terminal, the cold terminal of the
meter to the drain of the JFET, and both gate and source to the battery
negative.
This then reveals the Idss of the device, which we select for a small range,
say 9.5mA to 10.5mA.
Why is the Jeremy/Thorsten approach used? It doesn't seem to identify the
devices with an Idss of 10mA. Is it used to guarantee the directly coupled
cartridge is not subjected to DC? If so, I can see good reasons for this,
but you'd have to measure a lot of devices (at a couple bucks each
harumph...) to get the ones less than 2mV...
Cheers,
Hugh R. Dean
Melbourne, Australia
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: [JN] matching 2SK170s
Date: Wed, 23 Feb 2000 09:56:25 +0100
Source: Sound Digest Archive v02.n459
- ----------
> De : Allen Wright <AllenVSE@compuserve.com>
> A : David Home <DHome@creo.com>; JoeNet A <sound@lists.io.com>
> Objet : [JN] matching 2SK170s
> Date : mercredi 23 février 2000 01:38
> To get the fet to pass more than it's IDSS value you need to drive the
gate
> positive to the source - just like positive bias on a tube - and this is
> the "+" values you have on some of them.
>
> This is not a good operating point for a jfet that you want to operate in
a
> VERY linear manner right at the front of your signal path, so keep them
> aside for something else that will use them at lower currents. I would
use
> the -75mV pair myself.
Hello,
I disagree wholeheartedly! The most linear operating region for the 2SK170
as for all(most) Jfets is obtained for Vgs = 0V. That linear range is
extended from Vgs = +0.5V to -0.5V.
I don't think that in a preamp, specially for a MC cartridge you'll have to
manage with so large signals, so the bias point Vgs = 0 is IMHO the best.
For sure if you want a perfect matching with the Idss it is a bit difficult
that's why some may prefer to insert a small source resistance to perfect
the current bias.
> The positive (that is gate positive) are - in my experience of doing this
> mod for around 15 years now - unusable in your application. Remember that
> you have to liftthe grid of the upper cascode tube some 3 to 7 volts
above
> gnd - Thorsten suggested a 3.6V lithium battery, and I generally use a
> LM329 6.9V voltage reference chip
IMHO there is no relation between the Vgs of the Jfet and the Vgk of the
upper tube of the cascode.
In most of the case IMHO you can also use that one with a grounded grid
this give you a very simple large gain stage, 2 resistors being only used
(it is better also to select the tube between several). Lowest is the
number of passive elements more transparently sounding is a gain stage!
(ASCII art , please set your screen in COURRIER font)
B+
|
R2
|
o------OUTPUT
|
plate
grid-----o
cathod |
| |
drain |
INPUT--o---gate |
| source |
R1 | |
| | |
o-----o------o--GROUND
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] matching 2SK170s
Date: Wed, 23 Feb 2000 11:37:53 GMT
Source: Sound Digest Archive v02.n460
Hi there,
>If the JFET controls the current and we want minimum noise, then we use, as
>Jean-Michel has identified, no source resistor. Thus the source and the
>gate are tied to the same potential.
>
>Let's say we want, 10mA, then the logical test would be to grab a 6V
>battery, hook a mA meter to the positive terminal, the cold terminal of the
>meter to the drain of the JFET, and both gate and source to the battery
>negative.
That is actually just how I do it....
>This then reveals the Idss of the device, which we select for a small
>range, say 9.5mA to 10.5mA.
Yup, my recommended approach exactly.
>Why is the Jeremy/Thorsten approach used?
Sorry, not my approach at all....
Later Thorsten
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: Mick Maloney <supra@cantech.net.au>
Subject: [JN] Re: matching fets
Date: Wed, 23 Feb 2000 21:58:29 +0800
Source: Sound Digest Archive v02.n460
Allen Wright's piece on fet's was very helpful but I'm still wondering
exactly how these blackheads work and there seems to be some disagreement
about that.
I tried putting a 3V lithium battery on to the grid of my 417/2SK369 fet
Arthur Loesch phono with the fet shorted to earth- no "cathode" resistor.
It did amazing things to the sound and made it my best phono. But I didn't
do any selecting of fets and I got 8ma through both (L&R) cascodes- pretty
close to ideal-surely I couldn't have just lucked out and picked two good
fets out of blue sky. I'm a lucky bastard (I live in Australia)but I find
this hard to believe-any answers.
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: [JN] Matching JFETs, the Toccatta
Date: Wed, 23 Feb 2000 10:25:24 -0500
Source: Sound Digest Archive v02.n460
> Why is the Jeremy/Thorsten approach used? It doesn't seem to identify the
> devices with an Idss of 10mA.
Well, in Jeremy's case, I saw this matching fixture in Allen Wright's
preamp cookbook and i thought it would fit the bill. I picked a likely
current to match at (5mA) and sorted my JFETs according to Allen's
instructions. Did I screw this up? I don't know a whole lot about JFETs
or transistors (to name two of a long list) but I thought this was the
way to go. I haven't tried them in the Toccatta circuit yet to see if
they work correctly.
As I recall Mick was trying the Toccatta with a 3V battery between the
417A grid and ground and liked it. Mick, were you putting +3V on that
grid or -3V?
- -j
- --
=========================================
Jeremy Epstein .........jepstein@shwd.com
=========================================
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: Re: [JN] Matching JFETs, the Toccatta
Date: Wed, 23 Feb 2000 12:17:03 -0500
Source: Sound Digest Archive v02.n460
"T. Loesch" wrote:
>
> Hi there,
>
> >Well, in Jeremy's case, I saw this matching fixture in Allen Wright's
> >preamp cookbook and i thought it would fit the bill.
>
> Allens Fixture is not reall usable to determine the Idss of the FET. It
> allows a closer matching under the conditions the FET will operate,
> neccesary for Allens differentials.
OK, I kept a couple of pairs with various values, I hope I will end up
with a usable set (after all that effort) but I guess I matched them the
wrong way. I figured matched was matched and tis was the important
thing, but now I see that the current figure is of importance. You did
mention this, BTW, I wasn't looking for it so I didn't pick up on it
until now. (I thought matching at an arbitrary current would give me a
matched-well-enough set at other currents, and I did not understand that
the JFET itself would set the operating current through the tube and
that this was what I should select for.)
BTW, the ones I got from
> In my case I tried a number of FET Pairs that I had around in the Loesch
> Circuit. After some juggling Values and the like I arrived at the following:
>
> +B 250V
> +B Dropper Resistor 8.2k
> 417A Anode Resistor 10k
> J-Fet - 2SK147 with Idss 10mA (matched)
> J-Fet Source Resistor 50 Ohm
>
> This works, does not distort and sounds great. Use a different Idss FET, a
> different type of J-Fet or a Different +B Voltage or a different Anode/+B
> Dropepr resistor and you are out of luck. Getting this combo to work without
> a positive Voltage on the grid is quite "hairtrigger". Get it wrong and it
> sounds nasty.
Should I try +3V maybe, a la Mick Moloney?
The good news is I am used to doing this sort of juggling with the DC
amps I have built!
>
> I never really made that clear, though the text that goes with the Schematic
> for the Toccata MKII does explicitly mentions the FET and the Idss Value.
Dunno if I have that MKII or a previous drawing.
Well, I need to build it and see anyway, that seems to be part of the
answer in any case.
Thanks!
- -j
>
> Later Thorsten
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
- --
=========================================
Jeremy Epstein .........jepstein@shwd.com
=========================================
Sherwood Securities ... .. (800) 435 1240
=========================================
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Matching JFETs, the Toccatta
Date: Wed, 23 Feb 2000 16:40:49 GMT
Source: Sound Digest Archive v02.n460
Hi there,
>Well, in Jeremy's case, I saw this matching fixture in Allen Wright's
>preamp cookbook and i thought it would fit the bill.
Allens Fixture is not reall usable to determine the Idss of the FET. It
allows a closer matching under the conditions the FET will operate,
neccesary for Allens differentials.
In my case I tried a number of FET Pairs that I had around in the Loesch
Circuit. After some juggling Values and the like I arrived at the following:
+B 250V
+B Dropper Resistor 8.2k
417A Anode Resistor 10k
J-Fet - 2SK147 with Idss 10mA (matched)
J-Fet Source Resistor 50 Ohm
This works, does not distort and sounds great. Use a different Idss FET, a
different type of J-Fet or a Different +B Voltage or a different Anode/+B
Dropepr resistor and you are out of luck. Getting this combo to work without
a positive Voltage on the grid is quite "hairtrigger". Get it wrong and it
sounds nasty.
I never really made that clear, though the text that goes with the Schematic
for the Toccata MKII does explicitly mentions the FET and the Idss Value.
Later Thorsten
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: Re: [JN] Matching JFETs, the Toccatta
Date: Wed, 23 Feb 2000 20:05:57 -0500
Source: Sound Digest Archive v02.n461
Gents,
David said he had matched some fets - and had some questions. I spent
some time explaining my take on the oddities he found - that's point one.
He didn't ask how to find the IDSS of a fet so I didn't tell him, and my
jig shown in the TPCB is for matching fets to be used in differential
circuits - (which is vital for them to work as they should) and Thorsten
was correct in saying my matcher is for "matching" and not checking IDSS.
In my not so humble opinion - using a hi gm jfet as the bottom half of a
cascode with a tube works great in both SE and diff circuits, and the TPCB
and my www site shows both applications.
Jean-Michael and others say you should not use a source resistor in such a
circuit - in this I disagree for two practical reasons:
1/ My experience is that if the circuit already has enough gain for a MC
(as does the Arthur Loesch preamp) but is just too noisy - then adding the
fet _with the source grounded_ will normally give you too much gain, maybe
way too much!
But using a source resistor from betwen (say) 22 ohms and 150 ohms will
allow you to control the gain and yet make almost no effective difference
to the noise. Technically worse - yes, but it will still be SO much quieter
than the tube by itself that you won't notice.
Now if you needed all the gain you could get, like you were trying to get
ye ol' faithful RCA Tube Manual phono stage to boost up a low low output MC
then maybe you could try without the resistor...
Here now I have an unmodified RTP2 preamp from 1987 - fully diff and all
tube - and at the same volume setting I was using for comfortable music
earlier in the evening I can hear the damn hiss from 4 meters distance, and
through the noise of the fan in the Mac!
Yet the latest RTP3C with the fets in the front end (at the same gain) has
a "is it on?" noise level at the speaker, and w-a-y below even the best
record surface.
The SE FVP5 design that was in SP 15 is equally quiet with 47 ohms in the
source, and yet with only two stages in the phono has more than enough gain
for any cartridge I have had through here.
2/ This fet mod works which ever way you do it - but with a source resistor
_and_ fets that don't need to be biased positive to run the expected
current - you don't have to screw around matching the IDSS to the anode
load or some such magik routine - you just solder them in and go!
Jean-M also seems to say in his post that you can/should ground the grid of
the upper tube - again I disagree, at least if the upper tube is a ECC88,
417 or similar, hi gm and highish mu. I think Mike Malony had the best
description of adding a little voltage here. (And it's + to the upper tube
grid, David - or you make things worse, not better)
Matching fets to very close tolerances is vital in differential amps to
make the most of the possible CMRR - and the inherent distortion
cancellation - but in SE phonos I still suggest closely matched fets just
to ensure channel to channel conformity.
Enough for tonight.
Allen (VSE)
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: Re: [JN] Matching JFETs, the Toccatta
Date: Wed, 23 Feb 2000 20:07:12 -0700
Source: Sound Digest Archive v02.n461
The Inestimable Allen Wright :>) blessed us with:
> Gents,
> David said he had matched some fets - and had some questions. I spent
> some time explaining my take on the oddities he found - that's point one.
> He didn't ask how to find the IDSS of a fet so I didn't tell him, and my
> jig shown in the TPCB is for matching fets to be used in differential
> circuits - (which is vital for them to work as they should) and Thorsten
> was correct in saying my matcher is for "matching" and not checking IDSS.
Sorting for Idss is a simple matter in any case, just tie the source and
gate of the FET together, connect the +ve end of a low voltage battery, or
bench supply, to the FET's drain and the other end of the voltage source to
the ve terminal of a DVM set to measure DC current. Finally, connect the
+ve terminal of the DVM the joined source and gate leads of the FET.
Read Idss from the DVM . . .
> In my not so humble opinion - using a hi gm jfet as the bottom half of a
> cascode with a tube works great in both SE and diff circuits, and the TPCB
> and my www site shows both applications.
I agree wholeheartedly but add the following: paint the plastic body of
the FET with some conductive paint or other - Ultra-black India ink mixed
50/50 with WATER-based clear polyurethane works just fine. This done, wrap
one lead of a 10 meg resistor TIGHTLY around the painted body of the FET and
tie the other end to a smallish cap tied to ground. Tie the junction of the
cap and resistor to a 9V battery . . . . let this sit for a day or so to
allow the body of the FET to take up a charge . . . . then play a record and
give YOURSELF a charge ! ! !
>
> Jean-Michael and others say you should not use a source resistor in such a
> circuit - in this I disagree for two practical reasons:
>
> 1/ My experience is that if the circuit already has enough gain for a MC
> (as does the Arthur Loesch preamp) but is just too noisy - then adding the
> fet _with the source grounded_ will normally give you too much gain, maybe
> way too much!
Agreed . . .
> But using a source resistor from betwen (say) 22 ohms and 150 ohms will
> allow you to control the gain and yet make almost no effective difference
> to the noise. Technically worse - yes, but it will still be SO much quieter
> than the tube by itself that you won't notice.
The effective source R of a 2SK147 being on the order of 20-30 ohms, a
source resistor of up to 50 ohms will only degrade the 70+dB re: 500uV
signal to noise ratio by about 4-5 dB. If you can hear this against the
50/60dB s/n ratio of vinyl, your imagination is MUCH better than mine
>
> Now if you needed all the gain you could get, like you were trying to get
> ye ol' faithful RCA Tube Manual phono stage to boost up a low low output MC
> then maybe you could try without the resistor...
>
> Here now I have an unmodified RTP2 preamp from 1987 - fully diff and all
> tube - and at the same volume setting I was using for comfortable music
> earlier in the evening I can hear the damn hiss from 4 meters distance, and
> through the noise of the fan in the Mac!
. . . . ah but Allen, have you tried my Ultra Low Noise, Sooooper
SEEElected, whiz bang, cryo-treated toooobz?
> Yet the latest RTP3C with the fets in the front end (at the same gain) has
> an "is it on?" noise level at the speaker, and w-a-y below even the best
> record surface.
Yup, same here . . .
> The SE FVP5 design that was in SP 15 is equally quiet with 47 ohms in the
> source, and yet with only two stages in the phono has more than enough gain
> for any cartridge I have had through here.
Ditto . . . and who in their right mind wants to run some 50uV @ 1kHz
poooker of an MC anyway? That thing's output at 40Hz is on the order of
6-7uV fer chrissakes . . .
> 2/ This fet mod works which ever way you do it - but with a source resistor
> _and_ fets that don't need to be biased positive to run the expected
> current - you don't have to screw around matching the IDSS to the anode
> load or some such magik routine - you just solder them in and go!
Right again . . . . . This FET-phobia is just dogma. In the right place
in the circuit and used PROPERLY, three-legged pentodes work JUST FINE . . .
forever.
> Jean-M also seems to say in his post that you can/should ground the grid of
> the upper tube - again I disagree, at least if the upper tube is a ECC88,
> 417 or similar, hi gm and highish mu. I think Mike Malony had the best
> description of adding a little voltage here. (And it's + to the upper tube
> grid, David - or you make things worse, not better)
I have another stunt: put another triode atop the cascoding triode and,
using another 2SK147 as a current source tied between that tube's cathode
and control grid, tie that same control grid to the plate of the lower tube
to make a first rate active plate load for the lower tube/FET.
From the top tube's cathode, drop a voltage divider that might total
150K to ground. Select the resistor values to give a "mid-point" of about
6-8V and tie the lower triode's grid to this point. DO NOT run the drain of
the 2SK147 above about 10V - if you do a situation like "secondary emission"
occurs within the FET and this sounds uuuuUUUUggleee ! ! ! !
With a 2SK147 with 50ohms on its source at the bottom, this arrangement
gives about 55dB of gain that rolls away *gently* from about 30kHz.
A small "fudge factor" cap across the source resistor will extend the
bandwidth so that all of the +50Khz stylus/groove "rattle" can modulate the
audio signal to produce an effect commonly mistaken for "detail" by those
whose systems/ears are, shall we say, diminished in high frequency resolving
power. You can have all the bandwidth you want, just be prepared to pay for
it ! !
The output Z is, as I recall - this was many moons ago - about 10K and
this will drive a passive RIAA stage with alacrity and elan.
>
> Matching fets to very close tolerances is vital in differential amps to
> make the most of the possible CMRR - and the inherent distortion
> cancellation - but in SE phonos I still suggest closely matched fets just
> to ensure channel to channel conformity.
Here, here . . . . I got all anal about that and went out found an old
Tek 575 tube-type transistor curve tracer. Needless to say, FETs can be
MATCHED with this device.
Those who might suffer "equipment envy" over this can ease themselves
by watching eBay for a Tek 5100 series scope, a 5B10N Time Base and a
5CT1N Curve Tracer. The lot should be EASY to find for about $US400.00 and
then U 2 can match s/s devices to your heart's content . . .
> Enough for tonight.
Right again . . . back to the salt mine :<(
> Allen (VSE)
Bill - PEARL, Inc.
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: [JN] mathews@txc.com
Date: Thu, 29 Apr 1999 06:03:15 -0400
Source: Sound Digest Archive v02.n135
I got a private email from mathews@txc.com but my reply bounced. If you are
reading this can we try again?
Allen (VSE)
=========================================================================
From: "Dale Simon-contr" <Dale.Simon-contr@trw.com>
Subject: [JN] Re: math quiz
Date: Tue, 02 Oct 2001 13:38:22 -0400
Source: Sound Digest Archive v02.n987
Thanks for all the replies to my little math quiz (almost a dozen). You all get A's, except Al. Al
you better see me after class.
I'll have to come up with a harder one next time. ;-)
Dale
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: [JN] Mattes Transistor Amp
Date: Sun, 04 Jun 2000 10:32:45 -0700
Source: Sound Digest Archive v02.n564
Hi All,
This is a SS design of yesteryear (mid sixties) which most have probably
not seen, or heard of. It was designed with the objective of sounding
like a tube amplifier. I have one and have recently been playing about
with it.
It is a very attractive, well-built little amp, rated at 100
watts/channel, but will do a lot more, around 150 watts/chnl, as I
recall. It is built on a chassis much like a conventional tube power
amp, with a cage, so pretty well looks like a tube amp, with the cage
on. It uses a circuit referred to as the Sharma circuit, named after
its inventor.
The design approach bears a lot of similarity to the Harmpon Kardon amp
I recently described here, which sounds essentially identical to an
excellent PP tube amp which I also described in detail. While the HK
uses germanium transistors in a totem-pole arrangement, biased at a low
current and driven by an interstage transformer, the Sharma circuit uses
a single-ended driver stage, a 2N2148 germanium transistor, which is
coupled directly to the output for low-level signals, through
back-to-back diodes and a pull-up, and a pull down resistor. This same
stage also drives the interstage transformer which drives a pair of
silicon devices biased at zero volts. The theory is to drive the load
with the SE driver for small signals, then allow it to decouple and the
silicon power devices to turn on for large signal operation. Driving a
transistor base with a low impedance transformer is a good thing as it
provides adequate "off" drive (as well as "on" drive) to sweep out the
stored base charge and to supply the collector-to-base capacitive
current during the turn-off transition. In this manner you can pretty
well swamp the capacitive effects.
How do it sound? Quite good, in fact and it does indeed sound pretty
much like a tube amplifier, as does the similar Harmon Kardon receiver
previously referred to. For most music there is no discernable
artifacts, the exception being on an occasional bass note apparently in
the region where the speaker is highly reactive. Occasionally you can
hear a very annoying distortion where I presume the inductive current is
overwhelming the curent drive capability of the SE driver. Perhaps for
some speakers, there may be no artifacts, but I notice it occasionally
on my speakers.
I intend to mess about with it, either adding some auxilairy output
circuitry which is always biased on a bit, or perhaps try replacing the
output devices with FETS which have some quiescent bias at zero volts.
I haven't given it much serious thought though.
Anyway, an interesting approach that almost works and probably does with
some speakers. Perhaps I will try paralleling the speakers with an 8
ohm resistor to make them mainly resistive and see if this solves the
problem. Here are a couple pics, if you want to see how cute a SS amp
can be made.
http://home.att.net/~danmarshall/mattesfront.jpg
http://home.att.net/~danmarshall/mattesback.jpg
Since no one commented on the previous post, I assumed no one was
interested. Hiwever, I will reiterate that, when the HK was discussed a
couple years ago, when Lynn Olson was on the list, he noted that there
was a new design amplifier in the $4,000 price range which used this
type of circuit, so perhaps it is a design approach that should not be
casually swept aside. I am referring more specifically to the HK
circuit which is good for about 20 watts, not the Sharma circuit.
Dan Marshall
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] Mattes Transistor Amp
Date: Sat, 03 Jun 2000 15:11:10 -0500
Source: Sound Digest Archive v02.n565
"Daniel J. Marshall" wrote:
> Hi All,
>
> This is a SS design of yesteryear (mid sixties) which most have probably
> not seen, or heard of. It was designed with the objective of sounding
> like a tube amplifier. I have one and have recently been playing about
> with it.
>
> It is a very attractive, well-built little amp, rated at 100
> watts/channel, but will do a lot more, around 150 watts/chnl, as I
> recall. It is built on a chassis much like a conventional tube power
> amp, with a cage, so pretty well looks like a tube amp, with the cage
> on. It uses a circuit referred to as the Sharma circuit, named after
> its inventor.
Hi Dan
Boy it was nice to see one of those again, it turns out the place where I
was an apprentice as a kid, the guy who ran it, Bob Jordan was a friend of
the designer. Around the shop there were several prototypes, one of which I
glommed onto and tried to get going. The circuit is similar to the Delco
audio amp design using the DTG series germanium transistors.
In 1969, in highschool I sunk two months savings in 4 DTG 110b's for the amp
just to have it go ummmmm fittttt.
Even remember the coupling transformer, a Triad TY 160X.
I wouldn't bet the object was to make it sound like a tube amp, back then
the power was THE issue, remember even more than now, the majority of
speakers were crap. They didn't know about "tube amp sound" because that's
all there was. Stability was the primary problem designers faced "back
then".
The old days.
Tom Danley
Sound Physics Labs / Servodrive inc.
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] Mattes Transistor Amp
Date: Sun, 04 Jun 2000 08:20:49 -0500
Source: Sound Digest Archive v02.n565
"Daniel J. Marshall" wrote:
> > Hi Dan
> >
> <snip>
> >
> > I wouldn't bet the object was to make it sound like a tube amp, back then
> > the power was THE issue, remember even more than now, the majority of
> > speakers were crap. They didn't know about "tube amp sound" because that's
> > all there was. Stability was the primary problem designers faced "back
> > then".
> > The old days.
> >
> > Tom Danley
>
> Hi Tom,
>
> I have the original brochure which came with the amp. It describes the
> amp in detail, its performance specifications and how the Sharma circuit
> works. And it does specifically state that the design goal was to make
> a powerful, reliable transistor amp which did indeed sound like a tube
> amp. And it does. It also shows the recovery characteristics (a scope
> trace of the output waveform) following the removal of a dead short
> from the output terminals at full power.
>
>
Hi Dan
Well if you have a manual that says that (designed to sound like a tube amp) and
it is from the same era (late 60's) then its got to be. I can say that back
then power amplifiers were my main interest, I never heard anyone talking about
tube amp sound, that was all there was and the few SS amps around were thought
to be "better" because of the better spec's.
This was well before the time (early/mid 70's) when some listeners said "hey,
you know I think the tube amp sounds better" and I was able to get the Mcintosh
and other tube amp trade in's at the TV store for a song from fools who needed
the latest from Panosonic (before Technics).
Also back then (late 60's) when there were only Germanium transistors and later
in the early 70's when I worked at Precision Grommes when Silicon transistors
were available, the issue was stability and load fault tolerance.
Transistor amps back then died in the blink of an eye and when a part failed,
there was usually a cascade of other parts that failed too (out of sympathy).
At Grommes, the shift to solid state was a hard one, although it looked to me
like there 125 W amp circuit was essentially straight out of the RCA solid state
handbook. Al changed a few values and an over current circuit were added, come
to think of it, the protection circuit was one of the problems, it often went
into oscillation when activated.
Over all the tube amps were my favorite to work on although the high power and
lighter weight of SS was intriguing.
I may still have one of the Mattis blue driver boards and schematic around if
your in need.
Does it say anything about the name Mattis/Martin? for some reason the two
names are stuck together in my head.
You know the transformer coupled SS amp design stayed around for a surprising
time, into the late 80's a company called Hill still made pro-sound power amps
with a driver transformer, an output stage very much like the Mattis and Delco
circuits of the late 60's, maybe they still do.
Clearly transformer coupling got a bad reputation from the marketing folks, it
is a logical idea and has several nice features if one has a good transformer.
I am tempted to throw together a transformer coupled double, singled ended
bridge (ala circlotron) using emitter follower output connection (for a low
output Z without feedback) and transformer coupling, just for fun.
Cheers
Tom Danley
Sound Physics Labs / Servodrive inc.
Is the prefernce of Germanium over silicon based on the lower "drop" voltage or
something else?
=========================================================================
From: Neil Brown <neilb@telalink.net>
Subject: Re: [JN] Mattes Transistor Amp
Date: Sun, 04 Jun 2000 15:37:51 -0600
Source: Sound Digest Archive v02.n565
INtersting sounding. I have a pair of Transister driving transformers
Stancor made it sounds like this might work with. Anyone have a circuit diag
for this?
Neil
> From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
> Organization: Marshall Communications
> Reply-To: danmarshall@worldnet.att.net
> Date: Sun, 04 Jun 2000 10:32:45 -0700
> To: Joenet <sound@lists.io.com>
> Subject: [JN] Mattes Transistor Amp
>
> Hi All,
>
> This is a SS design of yesteryear (mid sixties) which most have probably
> not seen, or heard of. It was designed with the objective of sounding
> like a tube amplifier. I have one and have recently been playing about
> with it.
>
> It is a very attractive, well-built little amp, rated at 100
> watts/channel, but will do a lot more, around 150 watts/chnl, as I
> recall. It is built on a chassis much like a conventional tube power
> amp, with a cage, so pretty well looks like a tube amp, with the cage
> on. It uses a circuit referred to as the Sharma circuit, named after
> its inventor.
>
> The design approach bears a lot of similarity to the Harmpon Kardon amp
> I recently described here, which sounds essentially identical to an
> excellent PP tube amp which I also described in detail. While the HK
> uses germanium transistors in a totem-pole arrangement, biased at a low
> current and driven by an interstage transformer, the Sharma circuit uses
> a single-ended driver stage, a 2N2148 germanium transistor, which is
> coupled directly to the output for low-level signals, through
> back-to-back diodes and a pull-up, and a pull down resistor. This same
> stage also drives the interstage transformer which drives a pair of
> silicon devices biased at zero volts. The theory is to drive the load
> with the SE driver for small signals, then allow it to decouple and the
> silicon power devices to turn on for large signal operation. Driving a
> transistor base with a low impedance transformer is a good thing as it
> provides adequate "off" drive (as well as "on" drive) to sweep out the
> stored base charge and to supply the collector-to-base capacitive
> current during the turn-off transition. In this manner you can pretty
> well swamp the capacitive effects.
>
> How do it sound? Quite good, in fact and it does indeed sound pretty
> much like a tube amplifier, as does the similar Harmon Kardon receiver
> previously referred to. For most music there is no discernable
> artifacts, the exception being on an occasional bass note apparently in
> the region where the speaker is highly reactive. Occasionally you can
> hear a very annoying distortion where I presume the inductive current is
> overwhelming the curent drive capability of the SE driver. Perhaps for
> some speakers, there may be no artifacts, but I notice it occasionally
> on my speakers.
>
> I intend to mess about with it, either adding some auxilairy output
> circuitry which is always biased on a bit, or perhaps try replacing the
> output devices with FETS which have some quiescent bias at zero volts.
> I haven't given it much serious thought though.
>
> Anyway, an interesting approach that almost works and probably does with
> some speakers. Perhaps I will try paralleling the speakers with an 8
> ohm resistor to make them mainly resistive and see if this solves the
> problem. Here are a couple pics, if you want to see how cute a SS amp
> can be made.
>
> http://home.att.net/~danmarshall/mattesfront.jpg
>
> http://home.att.net/~danmarshall/mattesback.jpg
>
> Since no one commented on the previous post, I assumed no one was
> interested. Hiwever, I will reiterate that, when the HK was discussed a
> couple years ago, when Lynn Olson was on the list, he noted that there
> was a new design amplifier in the $4,000 price range which used this
> type of circuit, so perhaps it is a design approach that should not be
> casually swept aside. I am referring more specifically to the HK
> circuit which is good for about 20 watts, not the Sharma circuit.
>
>
>
> Dan Marshall
>
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: [JN] Mattes Transistor Amp
Date: Sun, 04 Jun 2000 17:39:07 -0700
Source: Sound Digest Archive v02.n565
> Hi Dan
>
<snip>
>
> I wouldn't bet the object was to make it sound like a tube amp, back then
> the power was THE issue, remember even more than now, the majority of
> speakers were crap. They didn't know about "tube amp sound" because that's
> all there was. Stability was the primary problem designers faced "back
> then".
> The old days.
>
> Tom Danley
Hi Tom,
I have the original brochure which came with the amp. It describes the
amp in detail, its performance specifications and how the Sharma circuit
works. And it does specifically state that the design goal was to make
a powerful, reliable transistor amp which did indeed sound like a tube
amp. And it does. It also shows the recovery characteristics (a scope
trace of the output waveform) following the removal of a dead short
from the output terminals at full power.
Come to think of it, I did try paralleling the speaker with an 8 ohm
resistor, as I suggested previously, and found that it did not like
driving low impedance loads, as was mentioned by Don C.
I don't have a complete circuit diagram, except for the output stage.
In further answer to Neil B. I would perhaps consider the Sharma
circuit (or perhaps a variation of it) for a high power amplifier,
probably using silicon devices, but would stick with the Harmon Kardon
design and germanium devices for a moderate-power amp, say, around 20
watts. The HK is not pickey about what kind of load it drives. A
shortcoming is the relative fragility of the 2N2147 devices. They
don't like to have the output shorted. Unfortunately, the 2N2147
output devices are not easy to come by, unless you come across an old HK
receiver, as I did recently. 2N2832s should also work well and at a bit
higher voltage than the 2N2147s. In fact, would be better to just snag
an old HK receiver and scrounge its bits and pieces. I would stay away
from the DTG series transistors, as they are MUCH slower than the 2N2147
and even moreso than the 2N2832. They also tend to have much lower
beta, as I recall from way back when, so require a more substantial
driver circuit and beefier ITs. I still have a few DTG1000s in the
parts cabinet, Darlington devices, as I recall.
The HK receiver at 20 Watts will play VERY loud with my current
speakers, much louder than can be tolerated. Also, I tend to prefer the
sound of very efficient speakers, so I lean toward the HK circuit
primarily for its greater load variation tolerance.
Dan Marshall
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: [JN] Mattes Transistor Amp
Date: Mon, 05 Jun 2000 10:18:14 -0400
Source: Sound Digest Archive v02.n566
Thomas Danley wrote:
>
> Is the prefernce of Germanium over silicon based on the lower "drop" voltage or
> something else?
I recall some discussion 10-15 years ago about the increased "electron
mobility" of germanium.
JL
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: [JN] Matti Otalla
Date: Wed, 07 Jun 2000 00:57:34 -0600
Source: Sound Digest Archive v02.n569
Hi All
I had a good long talk with my great friend Jennifer WhiteWolf tonite
about feedback-generated "phase noise" and of course Matti Otala's
name came up. It turns out that she's good pals with John Curl who is a
good friend of Matti's.
Matti it seems, is coming to the end of his days and is in the full-time
care of his nurses.
We're loosing another of the illuminated minds and more's the pity . . .
Treat the children well . . . .
Bill - PEARL, Inc.
=========================================================================
From: tube@jump.net
Subject: Re: [JN] Matti Otalla
Date: Wed, 07 Jun 2000 10:03:40 -0500
Source: Sound Digest Archive v02.n569
PEARL Cust Serv wrote:
> Hi All
> I had a good long talk with my great friend Jennifer WhiteWolf tonite
> about feedback-generated "phase noise" and of course Matti Otala's
> name came up. It turns out that she's good pals with John Curl who is a
> good friend of Matti's.
> Matti it seems, is coming to the end of his days and is in the full-time
> care of his nurses.
>
> We're loosing another of the illuminated minds and more's the pity . . .
>
> Treat the children well . . . .
>
> Bill - PEARL, Inc.
That really sucks. You know it has to happen eventually, but that doesn't
make it any better when you hear the news about someone like Matti.
Phil
=========================================================================
From: "Sylvain Giguere" <pagebleu@globetrotter.qc.ca>
Subject: [JN] Maus vs Lamhorns..
Date: Fri, 28 May 1999 23:30:28 -0400
Source: Sound Digest Archive v02.n155
Message en plusieurs parties et au format MIME.
- ------=_NextPart_000_002F_01BEA962.11FAF0A0
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charset="iso-8859-1"
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Johari wrote:=20
<<. I have experience with both but found
the MAU Vs very disappointing. I'm fortunate enough to have the chance =
to
audition the famous Lamhorn 2.0 recently in HK. I cannot say whether =
it's
the cabinet by Robert or the FR1 driver by Frank Rep plays a larger role =
in
the final sound but I can safely say that it's the most wonderful =
Lowther
sounding experience I have. >>
I have had a couple of Mau Horns in my living room at some point as well =
as the Acoustas with PM7As and heard different variations of the Maus as =
well at a friend's place and equally have heard the Lamhorns at Robert =
Lamarre's place (with our friend Reid Welch) and for sure, I have been =
disapointed by any of the Mau horns with their weird sound balance and =
sometimes disjointed low register. On the other hand, I have loved the =
Lamhonrs with Reps and just hummed along while foot tapping ... At some =
point Robert replaced the Reps by the Lowther drivers, and if there was =
a touch less "finesse" the coarse sound of the Lowthers in the treble =
was totally absent and the experience was very enjoyable, though not on =
a par with the Reps, but the price is not either...=20
Other than the Lamhorns, I have found the Acoustas to be the most =
honnest compromise with a Lowther, but still, I couldn't live with any =
of them except the Lamhorns.. sorry for that since I could not afford =
these babies...
Sylvain Gigu=E8re
- ------=_NextPart_000_002F_01BEA962.11FAF0A0
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charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
<HTML>
<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D'"MSHTML 4.72.2106.6"' name=3DGENERATOR>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000>Johari wrote: </FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000><<. I have experience with both but =
found<BR>the=20
MAU Vs very disappointing. I'm fortunate enough to have the chance=20
to<BR>audition the famous Lamhorn 2.0 recently in HK. I cannot say =
whether=20
it's<BR>the cabinet by Robert or the FR1 driver by Frank Rep plays a =
larger role=20
in<BR>the final sound but I can safely say that it's the most wonderful=20
Lowther<BR>sounding experience I have. >></FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>I have had a couple of Mau Horns in my living =
room at=20
some point as well as the Acoustas with PM7As and heard different =
variations of=20
the Maus as well at a friend's place and equally have heard the Lamhorns =
at=20
Robert Lamarre's place (with our friend Reid Welch) and for sure, I have =
been=20
disapointed by any of the Mau horns with their weird sound balance and =
sometimes=20
disjointed low register. On the other hand, I have loved the Lamhonrs =
with Reps=20
and just hummed along while foot tapping ... At some point Robert =
replaced the=20
Reps by the Lowther drivers, and if there was a touch less =
"finesse"=20
the coarse sound of the Lowthers in the treble was totally absent and =
the=20
experience was very enjoyable, though not on a par with the Reps, but =
the price=20
is not either... </FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>Other than the Lamhorns, I have found the =
Acoustas to=20
be the most honnest compromise with a Lowther, but still, I couldn't =
live with=20
any of them except the Lamhorns.. sorry for that since I could not =
afford these=20
babies...</FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>Sylvain =
Giguère</FONT></DIV></BODY></HTML>
- ------=_NextPart_000_002F_01BEA962.11FAF0A0--
=========================================================================
From: "johari yip" <hfyip@pacific.net.sg>
Subject: Re: [JN] Maus vs Lamhorns..
Date: Sat, 29 May 1999 15:51:58 +0800
Source: Sound Digest Archive v02.n156
This is a multi-part message in MIME format.
- ------=_NextPart_000_0037_01BEA9EB.2F10EE40
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charset="iso-8859-1"
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----- Original Message -----=20
From: Sylvain Giguere=20
To: sound@io.com=20
Sent: Saturday, May 29, 1999 11:30 AM
Subject: [JN] Maus vs Lamhorns..
Sylvain, you wrote
=20
>>I have had a couple of Mau Horns in my living room at some point as =
well as the Acoustas with PM7As and heard different variations of the =
Maus as well at a friend's place and equally have heard the Lamhorns at =
Robert Lamarre's place (with our friend Reid Welch) and for sure, I have =
been disapointed by any of the Mau horns with their weird sound balance =
and sometimes disjointed low register.<<=20
=20
No system is perfect. The "wierd sound balance and sometimes =
disjointed low register" as you have put it is not so serious as you =
might have discribed it to be. Like I have said, other than the slightly =
recessed lower register (male vocals sounds thinner), I have found that =
the MAU IVs are not bad for the money. With the kind of cash that you =
need to fork out, of course I would expect the sound to be nothing short =
of perfect.
=20
>>On the other hand, I have loved the Lamhonrs with Reps and just =
hummed along while foot tapping ... At some point Robert replaced the =
Reps by the Lowther drivers, and if there was a touch less "finesse" the =
coarse sound of the Lowthers in the treble was totally absent and the =
experience was very enjoyable, though not on a par with the Reps, but =
the price is not either... <<
I enjoyed the Lamhorns very much too but are you saying that the =
Lamhorns can remove all the bad characteristics in a stock Lowther =
driver when mounted on they? Which Lowther model are you talking about?
=20
>>Other than the Lamhorns, I have found the Acoustas to be the most =
honnest compromise with a Lowther, but still, I couldn't live with any =
of them except the Lamhorns.. sorry for that since I could not afford =
these babies...<<
IMHO, I feel the Acoustas are "coloured" in the low register. That's =
why it sounded so good with male vocals (Jim Reeves never sounded so =
good on Acoustas 8-)). Since you could not afford the Lamhorns(neither =
can I), what speakers are you listening to?
Johari
- ------=_NextPart_000_0037_01BEA9EB.2F10EE40
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D"MSHTML 5.00.2014.210" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A href=3D"mailto:pagebleu@globetrotter.qc.ca"=20
title=3Dpagebleu@globetrotter.qc.ca>Sylvain Giguere</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
href=3D"mailto:sound@io.com"=20
title=3Dsound@io.com>sound@io.com</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, May 29, 1999 =
11:30=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [JN] Maus vs =
Lamhorns..</DIV>
<DIV style=3D"FONT: 10pt arial"> </DIV>
<DIV style=3D"FONT: 10pt arial">Sylvain, you wrote</DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>>>I have had a couple of Mau Horns in =
my living=20
room at some point as well as the Acoustas with PM7As and heard =
different=20
variations of the Maus as well at a friend's place and equally have =
heard the=20
Lamhorns at Robert Lamarre's place (with our friend Reid Welch) and =
for sure,=20
I have been disapointed by any of the Mau horns with their weird sound =
balance=20
and sometimes disjointed low register.<< </FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>No system is perfect. The "wierd sound =
balance and=20
sometimes disjointed low register" as you have put it is not so =
serious as you=20
might have discribed it to be. Like I have said, other than the =
slightly=20
recessed lower register (male vocals sounds thinner), I have found =
that the=20
MAU IVs are not bad for the money. With the kind of cash that you =
need to=20
fork out, of course I would expect the sound to be nothing short of=20
perfect.</FONT></DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>>>On the other hand, I have loved the =
Lamhonrs=20
with Reps and just hummed along while foot tapping ... At some point =
Robert=20
replaced the Reps by the Lowther drivers, and if there was a touch =
less=20
"finesse" the coarse sound of the Lowthers in the treble was totally =
absent=20
and the experience was very enjoyable, though not on a par with the =
Reps, but=20
the price is not either... <<</FONT></DIV>
<DIV> </DIV>
<DIV>I enjoyed the Lamhorns very much too but are you saying=20
that the Lamhorns can remove all the bad characteristics in a =
stock=20
Lowther driver when mounted on they? Which Lowther model are you =
talking=20
about?</DIV>
<DIV><FONT color=3D#000000></FONT> </DIV>
<DIV><FONT color=3D#000000>>>Other than the Lamhorns, I have =
found the=20
Acoustas to be the most honnest compromise with a Lowther, but still, =
I=20
couldn't live with any of them except the Lamhorns.. sorry for that =
since I=20
could not afford these babies...<<</FONT></DIV>
<DIV> </DIV>
<DIV>IMHO, I feel the Acoustas are "coloured" in the low register. =
That's why=20
it sounded so good with male vocals (Jim Reeves never sounded so good =
on=20
Acoustas 8-)). Since you could not afford the Lamhorns(neither can I), =
what=20
speakers are you listening to?</DIV>
<DIV> </DIV>
<DIV>Johari</DIV></BLOCKQUOTE></BODY></HTML>
- ------=_NextPart_000_0037_01BEA9EB.2F10EE40--
=========================================================================
From: Torsten.Loesch@enhar-ha.nthames.nhs.uk
Subject: [JN] Mau vs. Lamm (Horn that is)....
Date: 27 May 1999 08:59:52 +0100
Source: Sound Digest Archive v02.n153
Hi all,
Has anyone got any views there? I think I'm somewhat at the trail of what is
done in the Lammhorns (or at least at something that might be used in a
similar format and would work).
What I dislike with the Mau Horns is their extreme Lenth/Depth....
I do have a small Room and yes, it's concrete. And while I'm persuing various
other schemes for a more efficient Speaker than I use now, I might still go
the Lowther Route....
So, any comment anyone?
Later Thorsten
=========================================================================
From: "johari yip" <hfyip@pacific.net.sg>
Subject: Re: [JN] Mau vs. Lamm (Horn that is)....
Date: Thu, 27 May 1999 22:47:14 +0800
Source: Sound Digest Archive v02.n153
Hi Thorsten and everyone,
Before we go any further, I would like to clarify that MAU IVs sounds very
different as compared to the MAU Vs. I have experience with both but found
the MAU Vs very disappointing. I'm fortunate enough to have the chance to
audition the famous Lamhorn 2.0 recently in HK. I cannot say whether it's
the cabinet by Robert or the FR1 driver by Frank Rep plays a larger role in
the final sound but I can safely say that it's the most wonderful Lowther
sounding experience I have. Wonderful midrange and highs but w/o the
floor-reaching bass. Very strong midbass though. It has the Lowther
characteristic but at the same time don't sound like a Lowther if you know
what I mean.
Johari
- ----- Original Message -----
From: <Torsten.Loesch@enhar-ha.nthames.nhs.uk>
Cc: <sound@lists.io.com>
Sent: Thursday, May 27, 1999 3:59 PM
Subject: [JN] Mau vs. Lamm (Horn that is)....
> Hi all,
>
> Has anyone got any views there? I think I'm somewhat at the trail of what
is
> done in the Lammhorns (or at least at something that might be used in a
> similar format and would work).
>
> What I dislike with the Mau Horns is their extreme Lenth/Depth....
>
> I do have a small Room and yes, it's concrete. And while I'm persuing
various
> other schemes for a more efficient Speaker than I use now, I might still
go
> the Lowther Route....
>
> So, any comment anyone?
>
> Later Thorsten
=========================================================================
From: "Robert Lamarre" <rlamarre@rlacoustique.com>
Subject: RE: [JN] Mau vs. Lamm (Horn that is)....
Date: Thu, 27 May 1999 19:28:24 -0000
Source: Sound Digest Archive v02.n154
Hi Thorsten, Johari and all,
I just wanted to mention that Johari probably heard the Lamhorn 1.8 and not
the 2.0
The internal horn design is quite different actually.
The sound is cleaner mids and more bass with the 1.8
Cheers,
- -------- Robert Lamarre --------
- ----- RL Acoustique, Canada ----
- ------ Ph/Fx: 450-653-3461 -----
- --- rlamarre@rlacoustique.com --
- ----- www.rlacoustique.com -----
- -----Original Message-----
From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
Behalf Of johari yip
Sent: Thursday, May 27, 1999 2:47 PM
To: Torsten.Loesch@enhar-ha.nthames.nhs.uk
Cc: sound@lists.io.com
Subject: Re: [JN] Mau vs. Lamm (Horn that is)....
Hi Thorsten and everyone,
Before we go any further, I would like to clarify that MAU IVs sounds very
different as compared to the MAU Vs. I have experience with both but found
the MAU Vs very disappointing. I'm fortunate enough