Sound Practices Mailing List Files - Volume 2
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: [JN] U80K data
Date: Wed, 29 Mar 2000 20:34:31 +0200
Source: Sound Digest Archive v02.n504
Hi all
Does anyone among you hasve data of an output transformer:
U80K, made by Amroh Holland
SE, 5-10 watt with multiple primary and secundary
Thanks in advance
Guido
At 11:18 29/03/2000 -0500, dave slagle wrote:
>
>>Doc B's C4S is $35/pair. He sells Magnequest plate chokes at 100H/10mA
>>for $90/pr, $110/pr at 20mA.
>
>wow.. i thought the ccs from doc was more... thanks for the correction
>
>i will also add jack at electraprint makes a 100hy plate choke for like $32
>a pop...
>
>dave
>
>
>
>
=========================================================================
From: "Richard Jones" <RJ0101@Sprynet.Com>
Subject: [JN] UBT-1
Date: Mon, 22 Feb 1999 17:14:11 -0600
Source: Sound Digest Archive v02.n056
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To all that have expressed interest:
Actually thinking about it.. the most that would be value to me at the =
moment would be cash.. as i need to buy new output iron.
Eventually this will become the basis of either a 6B4G, 2A3 or 300B amp =
with a 5842 Driver stage.
I need about 5-6W so a 300B looks like the one.
Richard
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<DIV><FONT color=3D#000000 size=3D2>To all that have expressed=20
interest:</FONT></DIV>
<DIV> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Actually thinking about it.. the =
most that would=20
be value to me at the moment would be cash.. as i need to buy new output =
iron.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Eventually this will become the =
basis of either=20
a 6B4G, 2A3 or 300B amp with a 5842 Driver stage.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>I need about 5-6W so a 300B looks =
like the=20
one.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Richard</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV></BODY></HTML>
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From: TubeGarden@aol.com
Subject: [JN] ubt-1 for 826
Date: Tue, 10 Jul 2001 13:29:11 EDT
Source: Sound Digest Archive v02.n923
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Greets!
Now Playing is O & J China KT-88 (as triode) thru ubt-1.
Please try it on the 826 and report :)
I like it on 6Y6G, 6550, EL34 and with mayo on toast.
I also have -2 and -3 available, but, I am having a dandy crush on the -1.
With the Lambda TD15MMM on 80 Hz ehorns, it is just wonderful.
I was using -2 and -3 for years, thinking "aim high" on Z...
Happy Ears!
Al B^}
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<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>Greets!
<BR>
<BR>Now Playing is O & J China KT-88 (as triode) thru ubt-1.
<BR>
<BR>Please try it on the 826 and report :)
<BR>
<BR>I like it on 6Y6G, 6550, EL34 and with mayo on toast.
<BR>
<BR>I also have -2 and -3 available, but, I am having a dandy crush on the -1.
<BR>
<BR>With the Lambda TD15MMM on 80 Hz ehorns, it is just wonderful.
<BR>
<BR>I was using -2 and -3 for years, thinking "aim high" on Z...
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR>
<BR> </FONT></HTML>
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=========================================================================
From: "Richard Jones" <RJ0101@Sprynet.Com>
Subject: [JN] UBT-1 Reply
Date: Sun, 21 Feb 1999 22:21:38 -0600
Source: Sound Digest Archive v02.n055
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To those who were interested,
Well... $80 each.
I am also looking for any 50,45,6B4G, 300B, 10 etc..
basically any classic output triode.
also looking for magnequest or electraprint trannies to replace these.
btw, i STILL have those Dynaudio D260 tweeters... make an offer on =
those.
Richard
TXS :)
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<DIV><FONT color=3D#000000 size=3D2>To those who were =
interested,</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Well... $80 each.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>I am also looking for any 50,45,6B4G, 300B, 10=20
etc..</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>basically any classic output triode.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>also looking for magnequest or electraprint trannies =
to=20
replace these.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>btw, i STILL have those Dynaudio D260 tweeters... =
make an=20
offer on those.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Richard</FONT></DIV>
<DIV><FONT size=3D2>TXS :)</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV></BODY></HTML>
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From: Sridhar Gantimahapatruni <Ganti@acta.com>
Subject: [JN] UBT1 tranny's SOLD
Date: Mon, 6 Dec 1999 20:44:07 -0800
Source: Sound Digest Archive v02.n355
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Both the pairs are sold. Thanks for your interest in tranny's
ganti
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<TITLE>UBT1 tranny's SOLD</TITLE>
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<BODY>
<P><FONT SIZE=2 FACE="Arial">Both the pairs are sold. Thanks for your interest in tranny's</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">ganti</FONT>
</P>
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From: John Levreault <jlevro@mediaone.net>
Subject: [JN] Uda amps
Date: Thu, 02 Mar 2000 12:04:53 -0500
Source: Sound Digest Archive v02.n471
Below are some observations and comments based on exchanges with Carter.
Hope it's not too boring. I've never built one of these things, so these
are just theoretical ramblings. If I've got anything wrong, please let
me know.
1. Grounded-grid stage
At first I was confused by the assertion that the voltage feedback tube
was running in a grounded-grid mode. However, now I understand that the
action of the opamp and voltage feedback tube will force the voltage on
the (-) input of the opamp to be equal to the voltage on the (+) input.
After all, that's the way opamps work. Referring to Uda's Figure 2,
since the (+) input is at ground (or some other DC voltage chosen for
convenience), then the voltage on the (-) input will also be ground.
Hence the correct usage of the "grounded grid" term. The cathode
resistor is there for biasing purposes and will create only a small
disruption in the "grounded-gridness" of the stage. In practice, the
output tube replaces the opamp.
2. Gain
Uda states that the gain of the compound stage comprised of the output
tube and the feedback tube is equal to (mu - 1), where mu is that of the
feedback tube. (I need to think about that a bit more, but I believe him
for now.) Furthermore, the gain of the input pentode will equal its
transconductance (gm) x Rd, which may be less than 1. This is because
the "top" of Rd is held at AC ground by virtue of the NFB of the voltage
feedback tube.
3. Output tube
In addition, Uda refers to the fact that the transconductance of the
output tube is absorbed by the feedback. This is true. The output tube
does not contribute to the overall gain of the amp.
In addition, one very important effect occurs by virtue of the feedback
path: The output impedance of the output pentode drops substantially.
This may be why the STC topology works so well with inexpensive
transformers. Generally speaking, cheap trannies don't have much in the
way of low frequency extension when used "normally". However, the LF
extension of any transformer will improve when driven from a relatively
low impedance, so the STC may indeed improve the LF response of such a
tranny. Uda reminds us that this topology is intended to achieve optimum
performance from inexpensive tubes and iron.
4. Constant current source (aka input pentode)
Proper biasing of the input pentode in critical to the operation of an
STC amp and may be where that KT88 design is failing.
The first problem is driving the grid of the output tube. Note that you
only need ~-15V of bias. If one were to ground the output tube cathode,
then we'd need to swing between -30 and ground on the grid of the output
tube. Therefore, if we want a direct-coupled driver, we need to elevate
the output tube cathode with a cathode resistor so that the
driver can operate off a positive plate voltage.
The second problem is that, with a direct-coupled driver, the quiescent
grid voltage of the output tube will be equal to the quiescent plate
voltage of the driver, in this case the input pentode. The higher the
driver plate voltage, the larger (and lossier) the cathode resistor on
the output tube. For best amplifier "efficiency", the plate voltage of
the driver will be as low as possible. However, very few tubes like to
work with low voltage, say 30V, on their plate, but the 6AK5 happens to
be one of them.
Pentodes in general are more capable of operating at low plate voltages
than triodes, although the 6DJ8/6922 is an exception. In order for a
pentode like the 6AK5 to operate properly (i.e. linearly), it needs some
screen voltage. The 6AK5 happens to operate with ~50V on the screen.
This screen voltage is derived from the cathode voltage of the output
tube. That means that, no matter what screen voltage is chosen for the
input pentode, its plate will [typically] swing from 30V BELOW its
screen to a voltage the same as that on its screen. Remember that the
input pentode is direct coupled to the output tube.
If you choose to use a different input pentode, then the cathode
resistor of the output tube must be chosen to develop enough screen
voltage for the input pentode. Can you use a 6AC7? Sure. But you'll
probably need at least 100V on its screen. That means a rather large
cathode resistor on the output tube, which will dissipate lots of heat
and require a larger power supply voltage. But it can be done. I think
the 6AK5 was very carefully chosen.
JL
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: [JN] uda schematics
Date: Mon, 26 Apr 1999 20:40:45 -0500
Source: Sound Digest Archive v02.n131
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Hi!
I've been working through this interesting web site.
- -----------------------------------------------------------------------
Please take a few minutes to look at this site.
Each amp photograph leads to a separate, larger
photo with [Japanese] description and a schematic.
Each schematic features many things. One thing=20
is the use of "stopping diodes." What is uda trying
to accomplish with these stepping diodes?
Once again, I wish I could read Japanese
--Carter
http://plaza6.mbn.or.jp/~6bm8_2/h_uda/index.htm=20
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<HEAD>
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HTML//EN">
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</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000 size=3D2>Hi!</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=3DArial size=3D2>I've been working through this =
interesting web=20
site.</FONT></DIV>
<DIV><FONT face=3DArial=20
size=3D2>----------------------------------------------------------------=
- -------</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Please take a few minutes to look at =
this=20
site.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2><BR></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Each amp photograph leads to a =
separate,=20
larger<BR></DIV></FONT>
<DIV><FONT color=3D#000000 size=3D2>photo with [Japanese] description =
and a=20
schematic.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Each schematic features many things. One thing =
</FONT></DIV>
<DIV><FONT size=3D2>is the use of "stopping diodes." =
What is uda=20
trying</FONT></DIV>
<DIV><FONT size=3D2>to accomplish with these stepping =
diodes?</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Once again, I wish I could read =
Japanese</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000=20
size=3D2> &nbs=
p;  =
; =
=20
<FONT color=3D#000000>--Carter</FONT></FONT></DIV><BR><A=20
href=3D"http://plaza6.mbn.or.jp/~6bm8_2/h_uda/index.htm">http://plaza6.mb=
n.or.jp/~6bm8_2/h_uda/index.htm</A>=20
</BODY></HTML>
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From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: [JN] uda schematics
Date: Tue, 27 Apr 1999 03:49:14 GMT
Source: Sound Digest Archive v02.n131
On Mon, 26 Apr 1999 20:40:45 -0500, "Carter Hendricks" <carter@i1.net>
wrote:
>Each amp photograph leads to a separate, larger
>
>photo with [Japanese] description and a schematic.
I particularly like the one built in what appears to be a tin of
Danish sugar cookies.
- --dnb
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] uda schematics
Date: Tue, 27 Apr 1999 22:21:01 -0400
Source: Sound Digest Archive v02.n133
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This is a very cool site. What ARE those diode stoppers for? Just slow
turn on for the B+ or something else? And, am I misreading the
schematics, or are the ground rails in the direct-coupled circuits
really tied to a negative supply? Very interesting...
Carter Hendricks wrote:
> Hi! I've been working through this interesting web
> site.----------------------------------------------------------------------- Please
> take a few minutes to look at this site. Each amp photograph leads to
> a separate, largerphoto with [Japanese] description and a
> schematic. Each schematic features many things. One thingis the use of
> "stopping diodes." What is uda tryingto accomplish with these
> stepping diodes? Once again, I wish I could read
> Japanese --Carter
>
>
> http://plaza6.mbn.or.jp/~6bm8_2/h_uda/index.htm
- --
Grover Gardner
groverg@postoffice.att.net
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<HTML>
<BODY BGCOLOR="#FFFFFF">
This is a very cool site. What ARE those diode stoppers for?
Just slow turn on for the B+ or something else? And, am I misreading
the schematics, or are the ground rails in the direct-coupled circuits
really tied to a negative supply? Very interesting...
<P>Carter Hendricks wrote:
<BLOCKQUOTE TYPE=CITE> <FONT COLOR="#000000"><FONT SIZE=-1>Hi!</FONT></FONT> <FONT FACE="A
rial"><FONT SIZE=-1>I've
been working through this interesting web site.</FONT></FONT><FONT FACE="Arial"><FONT SIZE=-1>------
-----------------------------------------------------------------</FONT></FONT> <FONT COLOR="#0
00000"><FONT SIZE=-1>Please
take a few minutes to look at this site.</FONT></FONT> <FONT FACE="Arial"><FONT SIZE=-1>Each
amp photograph leads to a separate, larger</FONT></FONT><FONT COLOR="#000000"><FONT SIZE=-1>photo
with [Japanese] description and a schematic.</FONT></FONT> <FONT SIZE=-1>Each
schematic features many things. One thing</FONT><FONT SIZE=-1>is the use
of "stopping diodes." What is uda trying</FONT><FONT SIZE=-1>to accomplish
with these stepping diodes?</FONT> <FONT SIZE=-1>Once again, I wish
I could read Japanese</FONT> <FONT COLOR="#000000"><FONT SIZE=-1>
&nbs
p;
- --Carter</FONT></FONT>
<P><BR><A HREF="http://plaza6.mbn.or.jp/~6bm8_2/h_uda/index.htm">http://plaza6.mbn.or.jp/~6bm8_2/h_u
da/index.htm</A></BLOCKQUOTE>
<P><BR>--
<BR>Grover Gardner
<BR>groverg@postoffice.att.net
<BR>
</BODY>
</HTML>
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From: longrie@mmace.nrl.navy.mil
Subject: Re: [JN] UDA sound-digest V2 #470
Date: Thu, 02 Mar 2000 10:53:56 +0000
Source: Sound Digest Archive v02.n471
So, which of you is Uda Man?
(sorry)
gary
>Date: Tue, 29 Feb 2000 20:24:51 -0600
>From: "Carter Hendricks" <carter@i1.net>
>Subject: [JN] Two fotos of Anna's Uda.
>
>Ken put a couple photographs of the
>little Uda amp at:
>
>
>http://home.i1.net/~carter
>
>1. The slides are backwards, I think.
>2. I've been constructing most things
>from a sheet of 1/8 inch aluminum, with
>the power supply and output transformers
>hung underneath. I've had good luck with
>a Sakuma/Sato ground bus system.
>
> --Carter
gary longrie
vacuum electronics branch
code 6840
building 208 room 336a
naval research laboratory
washington dc 20375
"It is no use saying, "We are doing our best." You
have got to succeed in doing what is necessary."
Winston Churchill
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: [JN] Uda / STC url
Date: Sun, 11 Jul 1999 12:57:20 -0500
Source: Sound Digest Archive v02.n202
Here is an introduction page which leads both
to the 6BM8 club and to Hiroshi Uda's English
and Japanese pages.
http://plaza28.mbn.or.jp/~6bm8/englith/index.htm
--Carter
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] ugly is as ugly does
Date: Tue, 7 Nov 2000 16:46:11 EST
Source: Sound Digest Archive v02.n724
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Greets!
Mayhaps one could listen to really ugly units using a pretty little cell
phone in a lovely room?
Happy Ears!
Al B^}
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<HTML><BODY BGCOLOR="#ffffff"><FONT SIZE=2>Greets!
<BR>
<BR>Mayhaps one could listen to really ugly units using a pretty little cell <BR>phone in a lovely r
oom?
<BR>
<BR>Happy Ears!
<BR>Al B^}</FONT></HTML>
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=========================================================================
From: Nicholas McKinney <nick@lambdacoustics.com>
Subject: [JN] Uh oh
Date: Thu, 09 Dec 1999 20:08:29 -0500
Source: Sound Digest Archive v02.n359
Well Folks, I have been working on writing an article describing alot of what I
have learned with audio. The original plan was to have it ready for New Years,
but reality is quickly setting in. So I have decided to break it up into
separate pieces and publish them as I can.
The first piece is actually the second piece ;-o Rather it deals with digital
vs analog issues, and mainly the problems with digital Cds when the engineer is
ignorant of his work. Now I am a total newbie when it comes to studio
engineering I will admit. However I did get a good education in waveform
analyzation during my time as an electronics warfare specialist for the US
military on the EA6B aircraft. In other words, I had to stare at dancing
frequencies on video screens for far too long in my life.
What I wrote about in the first part of this article is something I have
brought up before, but I think most did not understand what the hell I was
mumbling about. Now I have figured out a video capture program, this makes it
much easier for you to see what I see. I see alot of crap to be honest, I
cannot believe just how bad the situation is, and how good it really can be
with just a little education.
Anyway enjoy, critiques are welcome, the flame suit is donned, Nomex is now my
underwear.
http://www.lambdacoustics.com/library/whitepapers/inside_my_mind.htm
Nick
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
www.onelist.com/community/LambdaDrivers
=========================================================================
From: Nicholas McKinney <nick@lambdacoustics.com>
Subject: [JN] RE: Uh oh
Date: Fri, 10 Dec 1999 12:39:26 -0500
Source: Sound Digest Archive v02.n360
At 08:53 AM 12/10/99 -0600, Williams, Mark D. wrote:
>> Well Folks, I have been working on writing an article
>--snip--
>> separate pieces and publish them as I can.
>
>I have just read the first of the pieces and am blown away! I finally
>understand why so many CDs sound so bad! The issues presented are done
>clearly and in a way we amateurs can really understand!
Hi, that was the plan really, to show as simply as possible the true issues.
Now I like Cds for certain music when they are done right, but for classical,
jazz, and the like I was never as satisfied as when I had the turntable
spinning. After a while I put 2+2 together and gained some knowledge of the
true facts. Now I spread it like an infection ;-)
>-snip-
>> ignorant of his work. Now I am a total newbie when it comes to studio
>> engineering I will admit. However I did get a good education
>
>That education must have been something! I feel like I really understand how
>digital clipping destroys a great analog recording.
Yes, IMHO this is the biggest problem with digital. You can take any Cd that
Doug Sax recorded and not find a clip (they sound really good too.) However
you take a Telarc Cd and find 100 clips in 10 seconds of a track. So there are
people in the business who really know what is going on, we just need to get
the rest educated I think. Especially with small label Cd getting so much
bigger in the future.
>> cannot believe just how bad the situation is, and how good it
>> really can be
>> with just a little education.
>
>So now that you have presented the problem, I can't wait to hear how you
>would handle it. Nick this is really good stuff for those of us who want to
>know how to evaluate those subjective feelings of "this recording stinks".
With digital recording in Cool Edit it keeps these red meters that light and
stay lit if you clip. You can also have it scan a song for clips and it can
count them all. The biggest problem is getting the track into the computer
without changing anything. I use a Plextor CDR and the specific capture
program to do this, I was told that it was one of the better choices for this.
There are others though that work from what I understand.
The way to handle it is to teach everyone that makes their own digital
recordings what not to do. This problem has to be stopped at the source with
the piece is first recorded, unless you want to re-master every Cd you buy and
convert them to CDR (NOT!)
Nick
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
www.onelist.com/community/LambdaDrivers
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] RE: Uh oh
Date: Fri, 10 Dec 1999 15:40:42 -0500
Source: Sound Digest Archive v02.n360
Nicholas McKinney wrote:
>
> At 08:53 AM 12/10/99 -0600, Williams, Mark D. wrote:
> >> Well Folks, I have been working on writing an article
> >--snip--
> >> separate pieces and publish them as I can.
> >
> >I have just read the first of the pieces and am blown away! I finally
> >understand why so many CDs sound so bad! The issues presented are done
> >clearly and in a way we amateurs can really understand!
>
> Hi, that was the plan really, to show as simply as possible the true issues.
> Now I like Cds for certain music when they are done right, but for classical,
> jazz, and the like I was never as satisfied as when I had the turntable
> spinning. After a while I put 2+2 together and gained some knowledge of the
> true facts. Now I spread it like an infection ;-)
>
Which would be a good idea of the information was correct. To quote
from the article:
"Digital has a known problem with low resolution at low amplitudes with
the current 16bit format. Half of the 16bits cover the highest 6dB of
output, and the other 8 bits cover the rest down to the lowest
theoretical levels. This would be the lower 90dB if we assume a 96dB
range. Remember this is a logarithmic curve, not linear. If linear we
would use the same amount of bits to cover each dB of range, IE 2 bits
every 10dB. At the moment we use the first 8bits to cover ~90dB, and
the last 8 bits to cover just the loudest 6dB."
This is entirely incorrect. The digital encoding used on CDs, DATs,
digital milti-tracks etc. is LINEAR PCM, not logarithmic. While there
is a 32kHz 12-bit log encoding, it's NOT what is used on CD.
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: Nicholas McKinney <nick@lambdacoustics.com>
Subject: Re: [JN] RE: Uh oh
Date: Fri, 10 Dec 1999 18:22:31 -0500
Source: Sound Digest Archive v02.n360
At 03:40 PM 12/10/99 -0500, Roscoe Primrose wrote:
>Nicholas McKinney wrote:
>>
>> At 08:53 AM 12/10/99 -0600, Williams, Mark D. wrote:
>> >> Well Folks, I have been working on writing an article
>> >--snip--
>> >> separate pieces and publish them as I can.
>> >
>> >I have just read the first of the pieces and am blown away! I finally
>> >understand why so many CDs sound so bad! The issues presented are done
>> >clearly and in a way we amateurs can really understand!
>>
>> Hi, that was the plan really, to show as simply as possible the true issues.
>> Now I like Cds for certain music when they are done right, but for
classical,
>> jazz, and the like I was never as satisfied as when I had the turntable
>> spinning. After a while I put 2+2 together and gained some knowledge of the
>> true facts. Now I spread it like an infection ;-)
>>
>
>Which would be a good idea of the information was correct. To quote
>from the article:
>
>"Digital has a known problem with low resolution at low amplitudes with
>the current 16bit format. Half of the 16bits cover the highest 6dB of
>output, and the other 8 bits cover the rest down to the lowest
>theoretical levels. This would be the lower 90dB if we assume a 96dB
>range. Remember this is a logarithmic curve, not linear. If linear we
>would use the same amount of bits to cover each dB of range, IE 2 bits
>every 10dB. At the moment we use the first 8bits to cover ~90dB, and
>the last 8 bits to cover just the loudest 6dB."
>
>This is entirely incorrect. The digital encoding used on CDs, DATs,
>digital milti-tracks etc. is LINEAR PCM, not logarithmic. While there
>is a 32kHz 12-bit log encoding, it's NOT what is used on CD.
Hi Roscoe, you are saying that the bit rate is linear to the dB level and not
the voltage level?
If it is linear to the voltage level, then what I say is true.
If it is linear to the dB level, then what you say is true.
However, voltage and dB (power) are not linear to each other. A doubling of
voltage is quadrupling of power (6 dB). Hence the higher the voltage the
greater the difference between steps.
So, which one is linear and which one is logarithmic?
Nick
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
www.onelist.com/community/LambdaDrivers
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] RE: Uh oh
Date: Fri, 10 Dec 1999 19:27:31 EST
Source: Sound Digest Archive v02.n360
In a message dated 12/10/99 4:22:59 PM US Mountain Standard Time,
nick@lambdacoustics.com writes:
> If it is linear to the voltage level, then what I say is true.
>
> If it is linear to the dB level, then what you say is true.
>
> However, voltage and dB (power) are not linear to each other. A doubling
of
> voltage is quadrupling of power (6 dB). Hence the higher the voltage the
> greater the difference between steps.
Greets Jeets Neets,
Happy Holidays!
Let us give each other a clear picture of the hellish PCM swamp we dredge in
search of aural delights. (Yoda lives there)
16 bits gives us a linear voltage scale of 65,535 steps. 2 E 16
Each step is the same change in voltage.
We get 44,100 samples a second. More or less equally spaced in time
(jitterbugged)
A picture of the signal for one second is a lot of bits (16 x 44,100) = lots
A full resolution "scope image" would require a display image 65,535 pixels
high by 44,100 pixels wide to show the signal for one second.
How am I doing so far?
Happy Ears!
Al B^}
PS I just built a 5BK7A driving a pair of 5V6GT PULSE amp. (parafeed ultra
linear single ended) Now playing. Wow :)
Intel was close, it is a 4.7 volt world ;-)
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] RE: Uh oh
Date: Fri, 10 Dec 1999 21:12:47 -0500
Source: Sound Digest Archive v02.n360
Nicholas McKinney wrote:
>
> At 03:40 PM 12/10/99 -0500, Roscoe Primrose wrote:
> >Nicholas McKinney wrote:
> >>
> >> At 08:53 AM 12/10/99 -0600, Williams, Mark D. wrote:
> >> >> Well Folks, I have been working on writing an article
> >> >--snip--
> >> >> separate pieces and publish them as I can.
> >> >
> >> >I have just read the first of the pieces and am blown away! I finally
> >> >understand why so many CDs sound so bad! The issues presented are done
> >> >clearly and in a way we amateurs can really understand!
> >>
> >> Hi, that was the plan really, to show as simply as possible the true issues.
> >> Now I like Cds for certain music when they are done right, but for
> classical,
> >> jazz, and the like I was never as satisfied as when I had the turntable
> >> spinning. After a while I put 2+2 together and gained some knowledge of the
> >> true facts. Now I spread it like an infection ;-)
> >>
> >
> >Which would be a good idea of the information was correct. To quote
> >from the article:
> >
> >"Digital has a known problem with low resolution at low amplitudes with
> >the current 16bit format. Half of the 16bits cover the highest 6dB of
> >output, and the other 8 bits cover the rest down to the lowest
> >theoretical levels. This would be the lower 90dB if we assume a 96dB
> >range. Remember this is a logarithmic curve, not linear. If linear we
> >would use the same amount of bits to cover each dB of range, IE 2 bits
> >every 10dB. At the moment we use the first 8bits to cover ~90dB, and
> >the last 8 bits to cover just the loudest 6dB."
> >
> >This is entirely incorrect. The digital encoding used on CDs, DATs,
> >digital milti-tracks etc. is LINEAR PCM, not logarithmic. While there
> >is a 32kHz 12-bit log encoding, it's NOT what is used on CD.
>
> Hi Roscoe, you are saying that the bit rate is linear to the dB level and not
> the voltage level?
>
> If it is linear to the voltage level, then what I say is true.
>
> If it is linear to the dB level, then what you say is true.
>
> However, voltage and dB (power) are not linear to each other. A doubling of
> voltage is quadrupling of power (6 dB). Hence the higher the voltage the
> greater the difference between steps.
It is linear to the voltage level, but what you say is still not true,
you've got the logarithm backwards. In the 16bit system, it's 2s
compliment, so the value can range between +- about 32000. If we assume
that corresponds to +- 1V, then a signal varying between +- 16000
corresponds to +- 1/2V, and 1/4 the power (6dB down) of the full-scale
signal. So, the top 8 bits control 99.999% of the power (linear values
of power), or the loudest 48dB.
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: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] RE: Uh oh
Date: Fri, 10 Dec 1999 22:25:16 -0500
Source: Sound Digest Archive v02.n360
TubeGarden@aol.com wrote:
> In a message dated 12/10/99 4:22:59 PM US Mountain Standard Time,
> nick@lambdacoustics.com writes:
>
> > If it is linear to the voltage level, then what I say is true.
> >
> > If it is linear to the dB level, then what you say is true.
> >
> > However, voltage and dB (power) are not linear to each other. A doubling
> of
> > voltage is quadrupling of power (6 dB). Hence the higher the voltage the
> > greater the difference between steps.
>
> Greets Jeets Neets,
>
> Happy Holidays!
>
> Let us give each other a clear picture of the hellish PCM swamp we dredge in
> search of aural delights. (Yoda lives there)
ahh, the land of liquid audio
>
>
>
> 16 bits gives us a linear voltage scale of 65,535 steps. 2 E 16
>
> Each step is the same change in voltage.
>
Each step IS the same change in Voltage and this is a problem. The way this
works out, in a 16 bit system, the 8 most significant bits define the top half of
the range of voltage swing. This is fantastic resolution considering these bits
define the range from 0 dB to -6 dB. Each step here represents a tiny fraction of
a dB in change of loudness.
The remaining 8 bits define the lowest half of the possible voltage swing (the
remaining 90 dB) and one finds that as the level goes down, the larger loudness
step each bit represents until at the least significant bit equals a 6 dB change.
The fact that the medium is SOOOO top heavy with resolution and sparse at low
levels is probably what drives the recorder's of Nick's music to push past
digital 0 dB. On the other hand, maybe there ex pro sound guys who think there
not getting there moneys with unless the "red lights" are flashing regularly to
the beat.
Tom
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] RE: Uh oh
Date: Fri, 10 Dec 1999 23:01:42 -0500
Source: Sound Digest Archive v02.n360
Thomas Danley wrote:
>
> TubeGarden@aol.com wrote:
>
> > In a message dated 12/10/99 4:22:59 PM US Mountain Standard Time,
> > nick@lambdacoustics.com writes:
> >
> > > If it is linear to the voltage level, then what I say is true.
> > >
> > > If it is linear to the dB level, then what you say is true.
> > >
> > > However, voltage and dB (power) are not linear to each other. A doubling
> > of
> > > voltage is quadrupling of power (6 dB). Hence the higher the voltage the
> > > greater the difference between steps.
> >
> > Greets Jeets Neets,
> >
> > Happy Holidays!
> >
> > Let us give each other a clear picture of the hellish PCM swamp we dredge in
> > search of aural delights. (Yoda lives there)
>
> ahh, the land of liquid audio
>
> >
>
> >
> >
> > 16 bits gives us a linear voltage scale of 65,535 steps. 2 E 16
> >
> > Each step is the same change in voltage.
> >
>
> Each step IS the same change in Voltage and this is a problem. The way this
> works out, in a 16 bit system, the 8 most significant bits define the top half of
> the range of voltage swing. This is fantastic resolution considering these bits
> define the range from 0 dB to -6 dB. Each step here represents a tiny fraction of
> a dB in change of loudness.
>
> The remaining 8 bits define the lowest half of the possible voltage swing (the
> remaining 90 dB) and one finds that as the level goes down, the larger loudness
> step each bit represents until at the least significant bit equals a 6 dB change.
>
This too is incorrect. Yes, each of the 65,536 steps is the same change
in voltage. However, the top 8 bits DO NOT, repeat, DO NOT define the
range from 0dB to -6dB, they define the range from 0dB to -48dB! Do the
math, and you'll see you can't be right. Let's assume for a minute that
0dB is 2VRMS. IF the top 8 bits define the range from 0 to -6dB, (2VRMS
to 1VRMS) then the lower 8 bits which can only have 256 different
values, define a range of 1VRMS or 0.00390625v/step. That leave
65,535-256=65280 steps for the range from 1VRMS to 2VRMS, or
1.531862745098e-5V/step. Last time I checked, 1.531862745098e-5
doesn't equal 0.00390625....
In reality, back to our 0dB=2VRMS model, if we simply force the MSB to
0, we get 32768 steps, of the very same size, giving us a maximum
output of 1VRMS, or -6dB. This is exactly how the -6dB non-HDCD
attenuation is done in the digital domain (and why it's done in the
analog domain in most better HDCD DACS), they just shift everything down
a bit and make the MSB 0...
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: Nicholas McKinney <nick@lambdacoustics.com>
Subject: [JN] Re: Uh oh
Date: Sat, 11 Dec 1999 12:30:04 -0500
Source: Sound Digest Archive v02.n361
At 11:12 PM 12/10/99 +0000, Richard Howe wrote:
>Hi Nick,
>
>>Anyway enjoy, critiques are welcome, the flame suit is donned, Nomex is now
my
>>underwear.
>>
>>http://www.lambdacoustics.com/library/whitepapers/inside_my_mind.htm
>
>
>Interesting paper. But I must take issue with the presentation of the math in
>the opening paragraph of "The Software" and in particular:
>
>"Digital has a known problem with low resolution at low amplitudes with the
>current 16bit format. Half of the 16bits cover the highest 6dB of output, and
>the other 8 bits cover the rest down to the lowest theoretical levels. This
>would be the lower 90dB if we assume a 96dB range. Remember this is a
>logarithmic curve, not linear. If linear we would use the same amount of bits
>to cover each dB of range, IE 2 bits every 10dB. At the moment we use the
>first
>8bits to cover ~90dB, and the last 8 bits to cover just the loudest 6dB."
>
>It is true that half the numeric values are given to the top 6dB but this is
>not
>the same as 8 of the 16 bits. The 8 LSBs cover the first 48dB. The 8 MSBs
>cover the top 48dB. It is the sampling resolution which is linear and it is
>the
>dB scale which is logarithmic.
>
>The point I think you are trying to make is that we hear in a manner closer to
>the logarithmic than the linear scale. The effective sampling resolution
>therefore may appear to be less at lower dB levels. The resolution of the
>voltage signal is however the same.
>
>I guess one of us is missing something??
Hi Richard, Rene, and Roscoe, a peculiar thing happened last night. I was
asleep and woke up with a taste of "crow" in my mouth. Not knowing where this
crow came from, I looked around to find the culprit.
Yes the top 8 bits cover the top 48dB. The lower 15 bits cover the first half
of voltage swing.
Worse yet, I was completely sober when I made those other numbers.
So for those who have read the article, please disregard the nonsense about
bits.
The clips stay of course, that is something not related.
I think I will head down to the beach today where the only bits and bytes are
those from toothed animals beneath the waves.
Then "revision 1.1" will get uploaded soon after, with the proper bits.
Nick
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
www.onelist.com/community/LambdaDrivers
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] RE: Uh oh
Date: Sat, 11 Dec 1999 13:05:21 -0500
Source: Sound Digest Archive v02.n361
Roscoe Primrose wrote:
> Thomas Danley wrote:
> >
> > TubeGarden@aol.com wrote:
> >
> snip>
> > > 16 bits gives us a linear voltage scale of 65,535 steps. 2 E 16
> > >
> > > Each step is the same change in voltage.
> > >
> >
> > Each step IS the same change in Voltage and this is a problem. The way this
> > works out, in a 16 bit system, the 8 most significant bits define the top half of
> > the range of voltage swing. This is fantastic resolution considering these bits
> > define the range from 0 dB to -6 dB. Each step here represents a tiny fraction of
> > a dB in change of loudness.
> >
> > The remaining 8 bits define the lowest half of the possible voltage swing (the
> > remaining 90 dB) and one finds that as the level goes down, the larger loudness
> > step each bit represents until at the least significant bit equals a 6 dB change.
> >
>
> This too is incorrect. Yes, each of the 65,536 steps is the same change
> in voltage. However, the top 8 bits DO NOT, repeat, DO NOT define the
> range from 0dB to -6dB, they define the range from 0dB to -48dB! Do the
> math, and you'll see you can't be right. Let's assume for a minute that
> 0dB is 2VRMS. IF the top 8 bits define the range from 0 to -6dB, (2VRMS
> to 1VRMS) then the lower 8 bits which can only have 256 different
> values, define a range of 1VRMS or 0.00390625v/step. That leave
> 65,535-256=65280 steps for the range from 1VRMS to 2VRMS, or
> 1.531862745098e-5V/step. Last time I checked, 1.531862745098e-5
> doesn't equal 0.00390625....
>
> In reality, back to our 0dB=2VRMS model, if we simply force the MSB to
> 0, we get 32768 steps, of the very same size, giving us a maximum
> output of 1VRMS, or -6dB. This is exactly how the -6dB non-HDCD
> attenuation is done in the digital domain (and why it's done in the
> analog domain in most better HDCD DACS), they just shift everything down
> a bit and make the MSB 0...
>
> Peace
> --
> Roscoe Primrose
> -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe --
Hi Roscoe
You are correct, I had said the wrong thing. What I was getting at was that the current
scheme is a voltage incremental system where each voltage step has the same voltage
increment. This means that what ever "full scale" input voltage is, it is incremented
into 2^16 (65536) equal voltage steps.
As a result, half of the possible increments (at half the maximum voltage) represent
the highest 6 dB of signal range.
That may be hard to picture so to start lets simplify it.
Lets say we are dealing only with one polarity and a signal which goes from 0 to 10
volts.
With 16 bit resolution, the span of 0 to 10 is divided into 65536 equal voltage steps
(each step is 10v / 2^16) or ~.00015258 Volts). At 5 volts (half voltage = - 6dB from
0 dB), only 32768 voltage increments remain to describe the 90 dB that lies from 0 to 5
volts.
The issue is that as the level goes down, each increment represents a larger and larger
change in loudness until going from
increment 00001 to 00002 equals a 6 dB change. (going from .00015258 volts to
.00030516 volts is 6 dB)
With the audibility of the decreasing resolution (according to folks on the pro-sound
"recording engineer type" newsletter), there is an audible motivation to record as
close to zero dB as possible (also the level where the great measurements are taken),
in the cases Nick has found even attempting to go past 0 dB.
It is interesting that unlike nearly all the other parts of the reproduction process
who's performance degrades with increasing level, the CD process is the opposite.
I and others have wondered about the use of a log conversion process where the signal
would be divided into 65536 equal loudness steps. If one took the 96 dB of range and
broke it into 65536 steps, each would be .001465 dB and a step which would be below the
threshold of detection.
It has been pointed out that the log conversion process does produce artifacts when
dealing with signals of very different levels simultaneously, I suspect this is
unimportant as long as the reproduction was exactly the reciprocal log process. On
the other hand, maybe this is just a "DBX" process for digital, simply squeezing the
lower level information into the higher resolution recording levels.
Tom.
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: Re:[JN] Re: Uh oh
Date: Sat, 11 Dec 1999 16:28:18 -0700
Source: Sound Digest Archive v02.n361
Tom Danley wrote:
> I and others have wondered about the use of a log conversion process where
> the signal would be divided into 65536 equal loudness steps.
> If one took the 96 dB of range and broke it into 65536 steps, each would
> be .001465 dB and a step which would be below the threshold of detection.
> It has been pointed out that the log conversion process does produce
> artifacts when dealing with signals of very different levels simultaneously,
> I suspect this is unimportant as long as the reproduction was exactly the
> reciprocal log process. On the other hand, maybe this is just a "DBX" process
> for digital, simply squeezing the lower level information into the higher
> resolution recording levels.
>
> Tom.
================================
Hi Tom:
To me, this notion has enormous appeal - I wonder why it hasn't been
tinkered with at least, or has it? . . . . . Anyone . . . . ?
Bill - PEARL, Inc.
=========================================================================
From: SBench@aol.com
Subject: Re: [JN] Re: Uh oh
Date: Sat, 11 Dec 1999 22:05:56 EST
Source: Sound Digest Archive v02.n361
In a message dated 99-12-11 18:34:16 EST, custserv@pearl-hifi.com writes:
<< ================================
Hi Tom:
To me, this notion has enormous appeal - I wonder why it hasn't been
tinkered with at least, or has it? . . . . . Anyone . . . . ?
Bill - PEARL, Inc.
</XMP>
>>
Hi All,
Mu 255 law (8 bit) and A Law (also 8 bit, "E1") PCM companding is used
in all Telephony transmission. A law, even though 8 bits allows for
a 43 dB S/N ratio (caution on how that's defined)and better than
- -70 dB noise floor. One can not normally expect a -70 dB noise floor
with 8 bits!
Best Regards,
Steve
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] Re: Uh oh
Date: Sat, 11 Dec 1999 22:59:26 EST
Source: Sound Digest Archive v02.n361
In a message dated 12/11/99 8:15:27 PM US Mountain Standard Time,
SBench@aol.com writes:
> A Law (also 8 bit, "E1") PCM companding
Greets Jeets Neets,
Yup. My last officious duty was customer acceptance testing of my E-1 / A-Law
network.
As an audio concept, trying to get more info into less bits is the road to
madness.
Bits and processing are so cheap, the only realistic approach is more bits
more often.
The present PCM implementation suffers many weaknesses, one of which is
inability to deal with the arrival rate acceleration of musical information,
both faster and slower.
More and bigger samples are the brute force, read cheap, approach.
MP3 and other travesties offer nothing but aural insults.
Happy Ears!
Al B^}
=========================================================================
From: SBench@aol.com
Subject: Re: [JN] Re: Uh oh
Date: Sun, 12 Dec 1999 00:35:31 EST
Source: Sound Digest Archive v02.n361
In a message dated 99-12-11 23:03:55 EST, TubeGarden@aol.com writes:
<<
Yup. My last officious duty was customer acceptance testing of my E-1 /
A-Law
network.
As an audio concept, trying to get more info into less bits is the road to
madness.
<snip>
MP3 and other travesties offer nothing but aural insults. >>
Hi Al and all,
Also note that A law is 8 bits at 8kHz (64kbps). Which isn't even
medium fi. Does the term "telephone quality" ring a bell? (groan)
Mu law in T1 also suffers further from "robbed bit signalling" where
the least significant bit is stolen every 6 "frames". And the dxxn
frame isn't a direct multiple of 64k.(sigh) [193 bits= 24 channels + 1
extra bit per frame].
Probably drifted this thread off enough.
Best Regards,
Steve
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] Re: Uh oh
Date: Sun, 12 Dec 1999 07:09:38 EST
Source: Sound Digest Archive v02.n361
In a message dated 12/11/99 10:40:15 PM US Mountain Standard Time,
SBench@aol.com writes:
> Probably drifted this thread off enough.
Season's Greets Jeet Neets,
Ahhh, drifting is good for the soul :)
The 64 Kbs A-law signal is muxed with 23 other channels to become an E-1 link.
The goal was to time share the link and allow more concurrent traffic.
My goal is to simply keep the link as wide and quiet as possible.
These are divergent goals.
Compared to live, talking to someone on the phone is pretty dull.
So, is this the Thirteenth Day of Christmas? Or the Zeroeth day?
I noticed Santa looks pretty mellow this year, so, don't be afraid to tell
him what you REALLY want ;-)
Happy Ears!
Al B^}
=========================================================================
From: blackie <tubesville@yahoo.com>
Subject: Re: [JN] Re: Uh oh
Date: Sun, 12 Dec 1999 09:00:56 -0800 (PST)
Source: Sound Digest Archive v02.n361
- --- TubeGarden@aol.com wrote:
> MP3 and other travesties offer nothing but aural
> insults.
consider the positive side - increased access to
MUSIC!
as 'net bandwidth increases, we can expect better
formats...soon soon soon better better better
but we have the access NOW
check out www.spinner.com
make a juicy, low bandwidth system...and listen
non-stop to free music, huge variety, cutting edge programming...
=====
blackie
blackie@tubesville.com
www.tubesville.com
__________________________________________________
Do You Yahoo!?
Thousands of Stores. Millions of Products. All in one place.
Yahoo! Shopping: http://shopping.yahoo.com
=========================================================================
From: Kurt <kurt-steffensen@teliamail.dk>
Subject: Re: [JN] Re: Uh oh
Date: Sun, 12 Dec 1999 14:58:41 +0300
Source: Sound Digest Archive v02.n361
PEARL Cust Serv wrote:
> To me, this notion has enormous appeal - I wonder why it hasn't been
> tinkered with at least, or has it? . . . . . Anyone . . . . ?
I have also been thinking in these paths , and I am fully convinced that it IS
possible.
Sure some pitfalls are bound to be there , though , I am not experienced enough in
these matters to spot them clearly.
I have also been thinking about plexing between to systems , to increase both bit
range and handling frequency.
In my picture the optimal frequency should be beyond a 200KHz sampling rate.
I suppose the bit range , would not be that critical , if an active dynamic ,
system was developed.
Perhaps 20-24 would be more than good , in this case ?
I have noticed that there always seems to be MUCH confusion about the nature of
digital recording , processing and reproduction. - It is not limited to this list ,
it goes every where.
Especially the reasons , and causes for distortion and jitter is commonly
misunderstood.
It seems as if we humans can hardly avoid seeing the digital processing from an
analoge (Natural ) point of view.
It IS the case , such as Nick claims , that low signals , in the currently
available digital processing's , is a LOT poorer resolved ,
that the high signals.
And the system goes into "digital clipping" , at one sharp point , "with out
warning".
I am sure I can hear both phenomenon's on my system.
Very low signals sounds as if they are "boiling" or modulated with a weird noise.
And some transients just splash into the wall , no matter the volume set.
Maybe Steve , has played a little with the "dynamic controlled bitting" ?
After all he has been working with digital tele communications for many years , as
far as I know.......
(Are you with us , Steve ? )
I have just converted (back ) to netscape.
Boy , is this SO much better than the microsoft browser......
I am looking foreward to recieve an asci - scematic :-)
- - Kurt
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] Re: Uh oh
Date: Sun, 12 Dec 1999 16:21:17 EST
Source: Sound Digest Archive v02.n361
In a message dated 12/12/99 10:01:06 AM US Mountain Standard Time,
tubesville@yahoo.com writes:
> make a juicy, low bandwidth system...and listen
> non-stop to free music, huge variety, cutting edge programming...
Greets JN,
I have plump delishious fat bandwidth awesome dynamix system, with SD/DIF
from AWE 64 to trusty Audio Allergy Digital Decoping Engine v1.2 and I listen
to MP3 samples of new CDs from time to time, but I prefer sampler CDs and
those which come with magazines.
My favorite programming is SHUFFLE ALL DISCS on my 200 CD changer.
I find the lack of perky, hip banter wildly exciting :)
Holly Goludditely!
Al B^}
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: Re : [JN] Uh oh
Date: Tue, 14 Dec 1999 09:13:15 -0500
Source: Sound Digest Archive v02.n362
blackie <tubesville@yahoo.com> wrote :
> Subject: Re: [JN] Re: Uh oh
>
> - --- TubeGarden@aol.com wrote:
>
> > MP3 and other travesties offer nothing but aural
> > insults.
>
> consider the positive side - increased access to
> MUSIC!
>
> as 'net bandwidth increases, we can expect better
> formats...soon soon soon better better better
>
> but we have the access NOW
>
> check out www.spinner.com
>
> make a juicy, low bandwidth system...and listen
> non-stop to free music, huge variety, cutting edge programming...
This is merely the latest version of an old argument : do you listen to
your system or do you listen to music?
Myself, I don't get out the stereo steam-engine sound effects that
often, even thought they really sound cool and lay bare every single
flaw my system has (and there are many.)
I like being able to spin "Rocket 88" by Jackie Brenston, though, and
although it's pretty lo-fi it makes me shake my ass every time. Even the
CD reissue.
I hear people bitch about the CD format but honestly, how else are you
going to get good audio in your pocket? I tried the tip-top-of-the-line
cassette Walkman D-6C, it's pretty damn heavy, and doesn't sound nearly
as good as a much cheaper little Discman. And I don't know about you
guys, but I listen to stuff recorded in the last decade every now and
then.
Room for inmprovement? Sure, but that's what we're here for. Just never
forget how well off you are already!
- -j
- --
=====================================
Jeremy Epstein .... jepstein@shwd.com
=====================================
=========================================================================
From: blackie <tubesville@yahoo.com>
Subject: Re: Re : [JN] Uh oh
Date: Tue, 14 Dec 1999 12:08:41 -0800 (PST)
Source: Sound Digest Archive v02.n362
- --- Jeremy Epstein <jepstein@shwd.com> wrote:
> This is merely the latest version of an old argument
> : do you listen to
> your system or do you listen to music?
well, actually, BOTH
ya see, i don't have to choose between the two...just
take each one for what it has to offer
this way, win/win...
if MP-3 has a great distribution network, i'll listen
to the latest alt. country and rock, and buy what
appeals
hopefully the seedees will sound better on my high
bandwidth system, which i love with a great source
but, chuck berry still sounds better on my car
radio...
and kitty paige doesn't mind lee perry on the computer
speakers, whilst I surf...
=====
blackie
blackie@tubesville.com
www.tubesville.com
__________________________________________________
Do You Yahoo!?
Thousands of Stores. Millions of Products. All in one place.
Yahoo! Shopping: http://shopping.yahoo.com
=========================================================================
From: Richard C Nevill <rnevill@is.dal.ca>
Subject: Re: Re : [JN] Uh oh
Date: Tue, 14 Dec 1999 12:30:55 -0400 (AST)
Source: Sound Digest Archive v02.n362
On Tue, 14 Dec 1999, Jeremy Epstein wrote:
> as good as a much cheaper little Discman. And I don't know about you
> guys, but I listen to stuff recorded in the last decade every now and
> then.
>
> Room for inmprovement? Sure, but that's what we're here for. Just never
> forget how well off you are already!
>
Jeremy,
You make some excellent points. And I think we sometime lose track of
how lucky we are to be able to throw a couple swithches and have music
come at us. This list is an awful lot of fun and very educational for a
newish type person like myself, but often I'd rather just listen than
worry about caps or tubes.
Cheers
Richard Nevill
>
> --
> =====================================
> Jeremy Epstein .... jepstein@shwd.com
> =====================================
>
=========================================================================
From: "Mackris, Thom G." <tgmackris@vicorpinc.com>
Subject: Re : [JN] Uh oh
Date: Tue, 14 Dec 1999 14:19:48 -0700
Source: Sound Digest Archive v02.n362
Jeremy, all ..
There's a fantastic public radio station in Jeremy's & Blackie's back yard
if you're into sampling all kinds of weird jazz, world music, etc.
Check out WNYC FM at: http://www.wnyc.com/indexPicks.html
There's a program called "New Sounds" hosted by John Schaeffer & there are a
lot of segments available for listening. Click the "Music & Culture" link
to get there.
For all of you New Yawwwkers out there (my home town) the show is on late
evenings (11:00 PM, I believe).
I discovered groups like Oregon & many of the artists in the ECM stable
through this show back in the early-mid '80's. You're never sure where this
show is going to go, which I find to be refreshing.
Cheers,
Thom
- -----Original Message-----
From: Jeremy Epstein [mailto:jepstein@shwd.com]
Sent: Tuesday, December 14, 1999 7:13 AM
To: Joenet; Blackie Pagano
Subject: Re : [JN] Uh oh
{ snip ]
> consider the positive side - increased access to
> MUSIC!
> as 'net bandwidth increases, we can expect better
> formats...soon soon soon better better better
> but we have the access NOW
> check out www.spinner.com
=========================================================================
From: "jhlane" <jhlane@email.msn.com>
Subject: Re: Re : [JN] Uh oh
Date: Tue, 14 Dec 1999 17:50:17 -0800
Source: Sound Digest Archive v02.n363
> Me ?
> I am SO sophisticated , and better knowing.
ROTFL! Kurt, you are a gem. (But we already knew this about
you, so no surprise ;o)
And to think I thought I was...oh well, there's always room for
improvement.
Jon Lane
=========================================================================
From: Kurt Steffensen <kurt-steffensen@teliamail.dk>
Subject: Re: Re : [JN] Uh oh
Date: Tue, 14 Dec 1999 21:17:06 +0300
Source: Sound Digest Archive v02.n363
> This is merely the latest version of an old argument : do you listen to
> your system or do you listen to music?
Me ?
I listen to both.
I have quite a lot of lo-Fi records that I LOVE , and a few Hi-Fye that I
hate.......
Best of all , is when my favorite music is also very well recorded :-)
I remember a music teacher I had , many years ago. He had just about the
lousiest system I have EVER heard.
Really , really terrible.... - But , boy , he enjoyed it so much , listening
to his favorite operas , and with tears in his eyes ,
NEVER heard anything bad on the system. (Even on the opera voices !? )
I also know a few persons with , very good , expensive systems. Listening to
test records , and specially selected audiophile
albums day long.......?
I also know of persons , that tend to set their system up as a supermonitor
magnifying glass.
And persons that goes for the bam slam , speaker in the face...
And persons that sweetens their system to warm , romantic silky soft
valvie/toobie mild.........etc.
And the super bass , super treble 100 miles per hour , motorsaw approach.
Me ?
I am SO sophisticated , and better knowing. I am trying to bring the concert
hall , or monitor room , into my living room.
(What a silly , and naive approach )
But we all , enjoy it. - Using our hearing sense , getting pictures ,
feelings and so on.
There is no right way or wrong way , in my oponion. - Only different ways ,
and different goals and needs.
- - ´course , we all belive OUR way , is the best way....
(I think , I have been through , more or less , all the ways I have
descriped..... - And I have loved every minute of it :-)
- - Still do.........
( )
øø
U
(Enjoyed viking )
=========================================================================
From: TubeGarden@aol.com
Subject: Re : [JN] Uh oh 'computer speakers'
Date: Tue, 14 Dec 1999 15:31:02 EST
Source: Sound Digest Archive v02.n362
In a message dated 12/14/99 1:19:43 PM US Mountain Standard Time,
tubesville@yahoo.com writes:
> on the computer speakers, whilst I surf...
Hey Joes,
What 'computer speakers' do you use?
I am disabled and surf in my audio lab/bedroom using SP/DIF to my sys du
jour, but I know others have a computer room.
My wife, also disabled, but not bedridden, uses Radio Shack LX5ii on an old
Sony rcvr.
Just curious :)
Happy Ears!
Al B^}
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: Re : [JN] Uh oh 'computer speakers'
Date: Tue, 14 Dec 1999 14:59:08 -0800
Source: Sound Digest Archive v02.n363
>What 'computer speakers' do you use?
Monsoon MM-1000 at work -- awesome
Benwin NXT units at home (soon to be the subject of a project).
__________________
Transmission Line Speaker Page
http://139.142.118.15/sites/diy
=========================================================================
From: David Barnett <davidbarnett@aristotle.net>
Subject: Re: Re : [JN] Uh oh 'computer speakers'
Date: Tue, 14 Dec 1999 19:14:12 -0600
Source: Sound Digest Archive v02.n363
On Tue, 14 Dec 1999 15:31:02 EST, TubeGarden@aol.com wrote:
>What 'computer speakers' do you use?
Mine are Altecs and they're crap. Anyone heard anything halfway
decent in a computer speaker? The Monsoons look interesting, but I
haven't heard 'em.
- --dnb
=========================================================================
From: Scott Grammer <tubedude@sunnetusa.net>
Subject: Re: Re : [JN] Uh oh 'computer speakers'
Date: Wed, 15 Dec 1999 18:51:18 -0500
Source: Sound Digest Archive v02.n364
The Advents aren't bad.
Scott.
David Barnett wrote:
>
> On Tue, 14 Dec 1999 15:31:02 EST, TubeGarden@aol.com wrote:
>
> >What 'computer speakers' do you use?
>
> Mine are Altecs and they're crap. Anyone heard anything halfway
> decent in a computer speaker? The Monsoons look interesting, but I
> haven't heard 'em.
>
> --dnb
- --
"To save every cog and wheel is the first
precaution of intelligent tinkering." -Aldo Leopold.
What if there were no hypothetical questions?
=========================================================================
From: Thomas Dunker <dunker@invalid.ed.ntnu.no>
Subject: Re: Re : [JN] Uh oh 'computer speakers'
Date: Thu, 16 Dec 1999 03:43:48 +0100 (CET)
Source: Sound Digest Archive v02.n364
On Wed, 15 Dec 1999, Scott Grammer wrote:
> > On Tue, 14 Dec 1999 15:31:02 EST, TubeGarden@aol.com wrote:
> >
> > >What 'computer speakers' do you use?
> >
> > Mine are Altecs and they're crap. Anyone heard anything halfway
> > decent in a computer speaker? The Monsoons look interesting, but I
> > haven't heard 'em.
Hello guys,
Mine are a tri-amped triode and dipole/horn system. Sounds pretty decent.
SoundBlaster Live!, input to selector switch and attenuator, then to
5670/396A grids...have YOU heard your PC like THIS?
Next step will be 2 tube amplified (The vintage Philips AG9015) rear
channels, once I've found a pair of suitable speakers.
Right now playing "Das Boot - Director's Cut" on DVD...with that
one Marlene Dietrich song ("Aus meiner Privatsammlung" - anybody recognize
them?) on '78. :-)
Tom D.
- ------------------------------------------------------------------------
_/\_ Thomas Dunker \ The Horn Speaker Home Page:
/ \ P.O.Box 2811 \ http://invalid.ed.ntnu.no/~dunker/horns.html
| | 7002 Trondheim \
| | NORWAY \--\ "Those with head above water
\____/ dunker@omegav.ntnu.no \ see only the tip of the iceberg"
|||| phone: (+47)73911068 \ (Gene Dalby)
- ------------------------------------------------------------------------
=========================================================================
From: Nicholas McKinney <nick@lambdacoustics.com>
Subject: [JN] Uh oh (not again)
Date: Tue, 14 Dec 1999 16:40:05 -0500
Source: Sound Digest Archive v02.n363
Hi Folks,
I hate to bring this digital talk up again, however I corrected the math with
the digital, and added some more "juicy" parts.
Now some will really find problems with it I think ;-)
However, to discuss the problems is to find what the real issues are, and how
to best live with them. After all I listen to digital alot myself, without it
I also would not be able to go down to the local record shop and buy used (but
still fresh) records for $1~5 each.
So in reality, I really LOVE digital!
http://www.lambdacoustics.com/library/whitepapers/inside_my_mind.htm
Nick
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
www.onelist.com/community/LambdaDrivers
=========================================================================
From: AnnaLogg@aol.com
Subject: [JN] UK LP?
Date: Wed, 22 Dec 1999 09:16:17 EST
Source: Sound Digest Archive v02.n370
Can anyone tell me something about the Fontana label? Are these good quality?
I'm interested in something that seems to be either an RCA or London reissue
(opera set) but I have never heard of this label.
Any light you might be able to shed would be appreciated.
Thanks.
Anna
=========================================================================
From: Kurt Steffensen <kurt-steffensen@teliamail.dk>
Subject: Re: [JN] UK LP?
Date: Mon, 27 Dec 1999 17:04:48 +0300
Source: Sound Digest Archive v02.n372
Well , it seems like no one else is familiar with this label.
I have a few Fontana´s. Not enough to conclude anything about the general quality
,
but the ones of mine are fine.
I do suspect , that they are associated with Decca somehow ?
If the price is allright , and it is a good opera , I advice you to go for it :-)
- - Kurt
AnnaLogg@aol.com wrote:
> Can anyone tell me something about the Fontana label? Are these good quality?
> I'm interested in something that seems to be either an RCA or London reissue
> (opera set) but I have never heard of this label.
>
> Any light you might be able to shed would be appreciated.
>
> Thanks.
> Anna
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] UK LP?
Date: Mon, 27 Dec 1999 18:07:43 -0500
Source: Sound Digest Archive v02.n372
At 5:04 PM +0300 12/27/99, Kurt Steffensen wrote:
>Well , it seems like no one else is familiar with this label.
>
>I have a few Fontana´s. Not enough to conclude anything about the
>general quality
>,
>but the ones of mine are fine.
>
>I do suspect , that they are associated with Decca somehow ?
>
>If the price is allright , and it is a good opera , I advice you to
>go for it :-)
>
>- Kurt
>
>AnnaLogg@aol.com wrote:
>
> > Can anyone tell me something about the Fontana label? Are these
>good quality?
> > I'm interested in something that seems to be either an RCA or
>London reissue
> > (opera set) but I have never heard of this label.
> >
> > Any light you might be able to shed would be appreciated.
I agree with Kurt--in my experience the Fontana lable is a quality
budget line, reissuing Decca masters on reasonbale clean pressings.
I think they are worth picking up. Compared to the American budget
lines like Seraphim, Quintessence, etc., they are generally far
better.
- -------
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Ross J Lahlum <rlahlum@juno.com>
Subject: Re: [JN] UK LP?
Date: Mon, 27 Dec 1999 20:27:36 -0600
Source: Sound Digest Archive v02.n373
I'd agree with Kurt and Grover. I've accumulated a few Fontanas & they
sound pretty good. Not Shaded Dogs or Living Presence, but still well
above average. But the main thing for me is the music. If it's a
performance I like, I can tolerate slightly less than perfection...
Regards,
Ross
On Mon, 27 Dec 1999 18:07:43 -0500 Grover Gardner
<groverg@postoffice.att.net> writes:
> At 5:04 PM +0300 12/27/99, Kurt Steffensen wrote:
> >Well , it seems like no one else is familiar with this label.
> >
> >I have a few Fontana´s. Not enough to conclude anything about the
> >general quality
> >,
> >but the ones of mine are fine.
> >
> >I do suspect , that they are associated with Decca somehow ?
> >
> >If the price is allright , and it is a good opera , I advice you to
> >go for it :-)
> >
> >- Kurt
> >
> >AnnaLogg@aol.com wrote:
> >
> > > Can anyone tell me something about the Fontana label? Are these
> >good quality?
> > > I'm interested in something that seems to be either an RCA or
> >London reissue
> > > (opera set) but I have never heard of this label.
> > >
> > > Any light you might be able to shed would be appreciated.
>
> I agree with Kurt--in my experience the Fontana lable is a quality
> budget line, reissuing Decca masters on reasonbale clean pressings.
> I think they are worth picking up. Compared to the American budget
> lines like Seraphim, Quintessence, etc., they are generally far
> better.
>
>
> -------
> Grover Gardner
> groverg@postoffice.att.net
________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
=========================================================================
From: houndman@onix.com
Subject: [JN] UK LP?
Date: Tue, 28 Dec 1999 00:18:18 -0500
Source: Sound Digest Archive v02.n373
Always interesting to see my family name in lights on Wine, Cigars,
and now LP's. Have to find out more. Maybe a family member in Europe is
moonlighting.
- -----------
\/ince Fontana
phila, pa. usa
houndman@onix.com
Don't do Winders. Can't on ENIAC
=========================================================================
From: Steven <stevensl@mindspring.net>
Subject: [JN] Ultra-Fi Part 2
Date: Wed, 5 Apr 2000 21:38:53 -0400 (EDT)
Source: Sound Digest Archive v02.n511
well i didn't kill myself wiring up the 2nd ParaSEX amp.
two words: its freaking amazing!
okay 3 words..
the poor beast is chuging away on my Paul Oakenfold collection of Mp3's as
we speak. Sounds damn fine even for mp3! I ran some Holly Cole, Ben Harper
and Creed thru it. Who says tubes cant rock and roll. The Oakenfold is at
eviction levels. That 2.5 watt SE sounds better than my old adcom solid
state on a level of magnitude, on some old infinity mini's no less.
Wait till i get the horns! <drool>
now i need to do JC's micro 2A3, or maybe a killer 845se amp.
oh so many projects...
steven
=========================================================================
From: Dave Stagner <dstagner@icarus.net>
Subject: [JN] Ultra-fi webring started
Date: Fri, 12 Feb 1999 23:29:36 -0600 (CST)
Source: Sound Digest Archive v02.n043
I've started the Ultra-fi webring, for web sites related to our style of
audio reproduction. My goal is to unite all the various web pages of
Joenetters and others with interesting works. The webring is open to
commercial as well as personal sites, so long as they aren't throwbacks to
mainstream audio.
If you'd like to add your own site to the webring, please go to the home
page at http://tinpan.fortunecity.com/saints/668/index.html and follow the
instructions there. You'll need to fill out a form, and copy some text
into your own page. If you have any questions or comments about the
webring, please email me at ultrafi@fcmail.com. That's an address i'm
using just for webring management.
If you have a web site on your system, or audio in general, please add it
to the ring! The usefulness of the ring is a function of how many people
join it. I have a little site of my own on the ring now... it needs a LOT
of work, but it does have an online copy of The Fi Primer!
- -dave
Practice beautiful randomness and act kind of senseless.
<dstagner@icarus.net>
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: [JN] Ultralinear Cathod Follower (paper in Rev. Sci. Instr. 1960)
Date: Wed, 2 Jun 1999 12:27:22 +0200
Source: Sound Digest Archive v02.n163
I have very good quality scans of the 4 pages of Read's paper in Review of
Scientific Instruments 1960.
If someone can put them on his website, I'll send them to him.
Best regards,
Jean-Michel Le Cleac'h
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: [JN] Ultralinear Cathod Follower (paper in Rev. Sci. Instr. 1960)
Date: Wed, 02 Jun 1999 10:35:34
Source: Sound Digest Archive v02.n164
A 12:27 PM 6/2/99 +0200, Le Cleac'h J.-M. a écrit :
>I have very good quality scans of the 4 pages of Read's paper in Review of
>Scientific Instruments 1960.
>
>If someone can put them on his website, I'll send them to him.
>
>Best regards,
>
>Jean-Michel Le Cleac'h
>
>
We have space for posting files on the SON-QC website at onelist.com. Go
ahead, Jean-Michel, if you can figure out how to do it. If you need me to
authorize it as listowner, just let me know.
Regards,
David
=========================================================================
From: StepHydro@aol.com
Subject: [JN] Ultrapath circuit URL
Date: Wed, 1 Mar 2000 20:52:03 EST
Source: Sound Digest Archive v02.n470
Is that circuit published on the web?
My Electra Print URL is a transformer listing on Chris Beck's pages.
Cheers/Carron
=========================================================================
From: Chris and Susan Beck <n9zes@execpc.com>
Subject: Re: [JN] Ultrapath circuit URL
Date: Wed, 01 Mar 2000 22:06:47 -0600
Source: Sound Digest Archive v02.n470
It's on the "xdrive" www.xdrive.com under "schematics" called the
Ultrapre.jpg.
Login: joelist
Password: noise
I also have my version on my web pages, which is really quite similar.
I just added a second stage of RC filtering to the power supply, soon to
be LC when I rebuild it into a larger chassis.
Chris
http://www.execpc.com/~n9zes
StepHydro@aol.com wrote:
> Is that circuit published on the web?
>
> My Electra Print URL is a transformer listing on Chris Beck's pages.
>
> Cheers/Carron
=========================================================================
From: Rich Conte <rconte@attglobal.net>
Subject: [JN] Ultrapath Theory and Current VTV Article on same for SE DHT
Date: Thu, 12 Jul 2001 13:40:09 -0400
Source: Sound Digest Archive v02.n924
Dear Experts,
Does anyone have any experience with this model of moving the grounded
end of the cathode bias bypass electrlytic cap from ground reference to
the B+ reference, the AC Path theory.
Does this really make a difference v. leaving it to ground via an
electrolytic V. an Oil cap to B+?
Thanks for any experiences with it in SE DHT and/or PP Triodes.
Thanks for reading this.
What do you think of the Parafeed issue of the BUMP in the midrange?
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] Ultrapath Theory and Current VTV Article on same for SE DHT
Date: Thu, 12 Jul 2001 15:37:15 EDT
Source: Sound Digest Archive v02.n924
- --part1_f3.ccac9f3.287f566b_boundary
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Greets!
The VTV article by Lynn Olson revealed more about audio cat fights than the
circuits.
Tres bitch, but, not very helpful.
I have built a lot of parafeed circuits, and have not encountered any of the
goblins described. And, I tried smaller caps, but, for me, better sound
happened with 16 - 22 uF under the 'off the shelf PP transformer". Gauche moi!
I also did a parafeed/UL hybrid. SEE: www.tubecad.com letters.
Useful hint: in parafeed, return the cap below the OPT to the power tube
cathode. No sense getting the bias network into the loop.
No playtime logged on the AC Path theory, sorry.
Happy Ears!
Al B^}
PS I am planning to do a parafeed with my tube diode biased amp. Stay tuned.
- --part1_f3.ccac9f3.287f566b_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>The VTV article by Lynn Olson revealed more about audio cat fights than the
<BR>circuits.
<BR>
<BR>Tres bitch, but, not very helpful.
<BR>
<BR>I have built a lot of parafeed circuits, and have not encountered any of the
<BR>goblins described. And, I tried smaller caps, but, for me, better sound
<BR>happened with 16 - 22 uF under the 'off the shelf PP transformer". Gauche moi!
<BR>
<BR>I also did a parafeed/UL hybrid. SEE: www.tubecad.com letters.
<BR>
<BR>Useful hint: in parafeed, return the cap below the OPT to the power tube
<BR>cathode. No sense getting the bias network into the loop.
<BR>
<BR>No playtime logged on the AC Path theory, sorry.
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR>
<BR>PS I am planning to do a parafeed with my tube diode biased amp. Stay tuned.</FONT></HTML>
- --part1_f3.ccac9f3.287f566b_boundary--
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: [JN] Unbridle Some Pentodes ! ! Was: Brides of Cascode Grief
Date: Wed, 17 May 2000 14:36:24 -0600
Source: Sound Digest Archive v02.n549
P. de R. L. wrote:com>, <sound@lists.io.com>
> Hello again.
>
> First thanks Bill for the good sense - but I want a diff pair and someone
> said you can't make these with pentodes - can you?
Rubbish . . of course you can ! !
> Anyway here's the latest for those who can stand it!
SNIP
> It looks therefore as though I shall have to abandon Mr Hedge and use these
> fancy valves triode-strapped as diff pairs followed up with a trusty old
> 6BX7 or pair of strapped A2134s and then the cathode followers (on their
> pentode sinks) and then the output valves, which will need only -40V bias.
> All a bit silly really! But the amp has to be all balanced - one idea I am
> not abandoning.
There is a much better way of doing this, and once my webmaster gets
back on his feet we'll post an article on this very thing. What output tubes
do you want to drive?
> Sense of humour failure? Not at all - just a touch of cascode-itis!
>
> regards,
>
> Paul
Bill -PEARL, Inc.
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] Unbridle Some Pentodes ! ! Was: Brides of Cascode Grief
Date: Wed, 17 May 2000 22:45:29 +0100
Source: Sound Digest Archive v02.n549
Thanks once again Bill.
I'm a a peculiar fellow really - I just have to try those obscure valves - I
suppose that's why I am in this (I've found some excellent weird ones which
are on their way to me - 7150s - magnoval based stubby high=gm pentodes).
Anyway I love music too - organ music especially and this evening we have a
real treat here in England - BBC Radio 3 has devoted the entire evening to
organ music - my absolute favourite!
And remember all this is without "A word from our sponsor"! We are very
lucky.
Back to the project. at present I have built two good-sounding amplifiers -
one a push-pull triode-strapped 813 amp and the other using a p-p 6528. the
latter is all direct coupled and this is the way I want to go; anyone who
hears a DC amp will probably agree.
The valve I have found is the splendid 13E1. I have taken the trouble to
prepare (triode-strapped) curves which I will send but the file is 490k.
The example used for the curves is S/H and an average - it is better than
the two new ones I have! The 13E1 is a beam tetrode of 95W dissipation and
triode strapped Ra can be as low as 130 ohms. This means bandwidth and I
have ordered a transformer from Lundahl for the project. it also means low
voltage (high current) which means less money on capacitors!
The amplifier must be fully differential (the output stage will sit on a
sink too like my 6528 prototype) as ultimately I will build a balanced
pre-amp. Hence my interest in Hedge and his blasted cascodes! I believe
only in Class A push-pull (apologies to all the SE types, but that's the way
it is)- I have found that the more current I run through the 813s the better
it gets. In fact having all the parts to build another 813 amp I feel a
bit guilty, but as I said I just have to try these valves!
Sorry to have waffled for so long - if anyone wants the 13E1 curves, they
are most welcome to e-mail me.
Regards
paul
- ----- Original Message -----
From: PEARL Cust Serv <custserv@pearl-hifi.com>
To: <sound@lists.io.com>
Sent: Wednesday, May 17, 2000 9:36 PM
Subject: [JN] Unbridle Some Pentodes ! ! Was: Brides of Cascode Grief
> P. de R. L. wrote:com>, <sound@lists.io.com>
> > Hello again.
> >
> > First thanks Bill for the good sense - but I want a diff pair and
someone
> > said you can't make these with pentodes - can you?
> Rubbish . . of course you can ! !
>
> > Anyway here's the latest for those who can stand it!
> SNIP
> > It looks therefore as though I shall have to abandon Mr Hedge and use
these
> > fancy valves triode-strapped as diff pairs followed up with a trusty old
> > 6BX7 or pair of strapped A2134s and then the cathode followers (on their
> > pentode sinks) and then the output valves, which will need only -40V
bias.
> > All a bit silly really! But the amp has to be all balanced - one idea I
am
> > not abandoning.
> There is a much better way of doing this, and once my webmaster gets
> back on his feet we'll post an article on this very thing. What output
tubes
> do you want to drive?
>
> > Sense of humour failure? Not at all - just a touch of cascode-itis!
> >
> > regards,
> >
> > Paul
>
> Bill -PEARL, Inc.
>
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: Re: [JN] Unbridle Some Pentodes ! ! Was: Brides of Cascode Grief
Date: Wed, 17 May 2000 15:37:28 -0700
Source: Sound Digest Archive v02.n550
> There is a much better way of doing this, and once my webmaster gets
>back on his feet we'll post an article on this very thing. What output tubes
>do you want to drive?
The Webmaster is still not on his feet, but he has uploaded another set of
Bill's pdfs. The listing is still crude, but it is time to go have another
nap. Bill can give us a quick lowdown on what these are all about (wink,
wink, nudge, nudge).
http://homepage.mac.com/planet10/PEARL-hifi/papers.html
dave
______________________
Trust your ears, listen, practice hard
=========================================================================
From: "John Levreault" <jlevro@mediaone.net>
Subject: [JN] Understand capacitor soakage to optimize analog systems
Date: Thu, 30 Aug 2001 08:45:05 -0400
Source: Sound Digest Archive v02.n957
This is a multi-part message in MIME format.
- ------=_NextPart_000_0005_01C13130.110424C0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
For all you capacitor junkies out there:
http://www.national.com/rap/Application/0,1570,28,00.html
- ------=_NextPart_000_0005_01C13130.110424C0
Content-Type: application/octet-stream;
name="Understand capacitor soakage to optimize analog systems.url"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
filename="Understand capacitor soakage to optimize analog systems.url"
[DEFAULT]
BASEURL=http://www.national.com/rap/Application/0,1570,28,00.html
[InternetShortcut]
URL=http://www.national.com/rap/Application/0,1570,28,00.html
Modified=C086807A5131C10184
- ------=_NextPart_000_0005_01C13130.110424C0--
=========================================================================
From: "John Levreault" <jlevro@mediaone.net>
Subject: Re: [JN] Understand capacitor soakage to optimize analog systems
Date: Thu, 30 Aug 2001 09:07:31 -0400
Source: Sound Digest Archive v02.n957
Oops. Sorry about the attachment. But it is a good article.
JL
- ----- Original Message -----
From: "John Levreault" <jlevro@mediaone.net>
To: "JoeNet" <sound@lists.io.com>
Sent: Thursday, August 30, 2001 8:45 AM
Subject: [JN] Understand capacitor soakage to optimize analog systems
> For all you capacitor junkies out there:
>
> http://www.national.com/rap/Application/0,1570,28,00.html
>
=========================================================================
From: SBench@aol.com
Subject: Re: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 00:19:15 EDT
Source: Sound Digest Archive v02.n262
In a message dated 99-08-24 22:53:42 EDT, rbales@gte.net writes:
<<
We know the 7027A is much like the rest of the 6L6 family and these
points are within the ratings of the 7581. Hell, the tube companies
even used the same damn curves for both tube types. So the big
question is how close do you suppose this operating point will get me
to true joy and happiness? Were the tube makers trying to sell more
of the *NEW and Improved* 7027 by not listing the really cool
operating points for the old 7581, or was there a real reason?
Is this a case where I just have to build it and then tell everybody.
>>
Hi Ron,
Experiment with different operating points before casting it in -er- nickel.
The one tube I *know* is VERY sensitive to screen grid voltage is the
6146 family. Different voltages can cause you to go from very sweet sound
to a really dirty one.
I've found some sensitivity like this with 6L6GC and 5881 based amps, but
not to the same degree as the 6146.
Best Regards,
Steve
=========================================================================
From: rbales@gte.net (Ron Bales)
Subject: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 02:43:39 GMT
Source: Sound Digest Archive v02.n262
Hey Joes,
Been lurking for awhile, mostly flaming RATs and building stuff. I
think the amp on my site is new since I was last active around here.
http://home1.gte.net/rbales/index.htm
Have a new project that I could use some guidance on. I have another
chassis pan like the one on the site - a set of Peerless trannies: one
power and two 6.6K outputs - know where to find a nickel plater - got
a matched quad of 7581 - Got a great looking panel meter and some
rotary switches - a junk box overflowing with sockets and caps and
tubes - and I am going to build the Williamson I never had as a child.
I'm looking into changing the tube lin-up. Nothing wrong with the
original SN7s, in fact I'm amazed at how many Williamson variants
didn't change a thing. I'll probably use 5687 for the diff/driver
stage. I've got plenty and they look perfect for the job on paper.
The front stage tube pair is trickier. The problem is to balance the
Vp on the first tube with the bias point on the direct connected
split-load splitter tube with both working happily. These don't need
to be the same tube, except for convenience and economy. If I was
interested in either of those things I'd have sold my tubes long ago.
I'm sure I'll find an interesting and effective set - only a matter of
grinding through the options and selecting the set of compromises I
can live with.
Now the question part is the output stage. To suit the tranny Z of
6.6K I'll be running the outputs as pentodes, I'm thinking of using a
VR tube for the added glow and to drop the screen V right onto the
money, or at least 105V down from the Plate. I see operating points
for the 7027A that look exactly like what I want to run my output at:
400V B+,
300V Screen
200R Cathode resistance
52VAC drive voltage.
Results
32W Output
2% THD
We know the 7027A is much like the rest of the 6L6 family and these
points are within the ratings of the 7581. Hell, the tube companies
even used the same damn curves for both tube types. So the big
question is how close do you suppose this operating point will get me
to true joy and happiness? Were the tube makers trying to sell more
of the *NEW and Improved* 7027 by not listing the really cool
operating points for the old 7581, or was there a real reason?
Is this a case where I just have to build it and then tell everybody.
Thanks for any input or encouragement with this monster.
ROn
=========================================================================
From: Scott Grammer <tubedude@sunnetusa.net>
Subject: Re: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 06:30:18 -0400
Source: Sound Digest Archive v02.n262
SBench@aol.com wrote:
>
> In a message dated 99-08-24 22:53:42 EDT, rbales@gte.net writes:
>
> <<
> We know the 7027A is much like the rest of the 6L6 family and these
> points are within the ratings of the 7581. Hell, the tube companies
> even used the same damn curves for both tube types. (snip)
The 7027 is a bodacious tube!
A couple of years ago I built a new amp in an ST70 chassis for a friend,
and built it around 7027's. It was a monster, but I ended up using
EL34's because of availability problems with the 7027.
Too bad.
S.G.
- --
"To save every cog and wheel is the first
precaution of intelligent tinkering." -Aldo Leopold.
What if there were no hypothetical questions?
=========================================================================
From: Ken Gilbert <ride5000@ride.ri.net>
Subject: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 07:52:50 -0400
Source: Sound Digest Archive v02.n262
>We know the 7027A is much like the rest of the 6L6 family and these
>points are within the ratings of the 7581. Hell, the tube companies
>even used the same damn curves for both tube types. So the big
>question is how close do you suppose this operating point will get me
>to true joy and happiness? Were the tube makers trying to sell more
>of the *NEW and Improved* 7027 by not listing the really cool
>operating points for the old 7581, or was there a real reason?
Ron, are you dead-set on the 7027? In every amp I have heard them in, the
Chineese (!) KT-66's are absolutely killer in tone.
Next to the KT90 it's my favorite BT.
- -Ken
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 08:31:09
Source: Sound Digest Archive v02.n263
A 07:52 AM 8/25/99 -0400, Ken Gilbert a écrit :
>
>>We know the 7027A is much like the rest of the 6L6 family and these
>>points are within the ratings of the 7581. Hell, the tube companies
>>even used the same damn curves for both tube types. So the big
>>question is how close do you suppose this operating point will get me
>>to true joy and happiness? Were the tube makers trying to sell more
>>of the *NEW and Improved* 7027 by not listing the really cool
>>operating points for the old 7581, or was there a real reason?
>
>Ron, are you dead-set on the 7027? In every amp I have heard them in, the
>Chineese (!) KT-66's are absolutely killer in tone.
>
>Next to the KT90 it's my favorite BT.
>
>-Ken
>
Is a beam power tube correctly called a pentode?
dbk
=========================================================================
From: "Mackris, Thom G." <tgmackris@vicorpinc.com>
Subject: RE: Sv: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 11:49:22 -0600
Source: Sound Digest Archive v02.n263
Hi Dave,
Not to stir up any glowing embers... but ... I find that the times I've
screwed up most in this hobby is when I ignored the missus :-) That damn
left brain of mine works overtime :-(
Regards,
Thom
Dave Klein wrote ...
- ---------------------------
Having just sold my favorite Eico chassis (an HF 89 and a pair of HF 22s)
to two list members, the answer is probably not again in this life. I still
have two Eicos left, though, so you never know. The missus likes the tube
sound ...
dbk
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: Sv: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 11:51:39
Source: Sound Digest Archive v02.n263
A 05:25 PM 8/25/99 +0300, Kurt Th. Steffensen a écrit :
>
>>Is a beam power tube correctly called a pentode?
>
>
>No. It is not a genuine pentode , in the normal content.
>The pentode does not "beam" the electron flow.
>
>Pentodes has better transfering characteristics that the beam tube.
>(Or beam pentode , as some calls it)
>
>Most European power tubes are genuine pentodes , exept the KT series.
>
>And I belive that about all , US made power pentodes , are the beam
technology.
>These are more effective , but the price is less linearity.
>
>Do you plan to build a Beam power amp , David ? ;-)
Having just sold my favorite Eico chassis (an HF 89 and a pair of HF 22s)
to two list members, the answer is probably not again in this life. I still
have two Eicos left, though, so you never know. The missus likes the tube
sound ...
dbk
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: RE: Sv: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 12:33:14 -0600 (MDT)
Source: Sound Digest Archive v02.n263
On Wed, 25 Aug 1999, David B. Klein wrote:
> You have no idea how hard it was for me to part with the HF89 iron. When I
> last had those trannies running as a high-powered 6550 Class AB P-P, it was
> glorious. I was getting just about 80 W/Ch with a B+ that was, to the best
> of my recollection, close to 550 V, with all solid-state regulation.
> Without a tube rectifier drop, that's about what you end up with.
What a coarse oaf you continue to be. That voltage drop is sacred when it
is produced by gaseous emission.
Doug Purl
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: RE: Sv: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 14:00:31
Source: Sound Digest Archive v02.n263
A 11:49 AM 8/25/99 -0600, Mackris, Thom G. a écrit :
>Hi Dave,
>
>Not to stir up any glowing embers... but ... I find that the times I've
>screwed up most in this hobby is when I ignored the missus :-) That damn
>left brain of mine works overtime :-(
>
>Regards,
>Thom
>
>Dave Klein wrote ...
>---------------------------
>Having just sold my favorite Eico chassis (an HF 89 and a pair of HF 22s)
>to two list members, the answer is probably not again in this life. I still
>have two Eicos left, though, so you never know. The missus likes the tube
>sound ...
>
>dbk
>
You have no idea how hard it was for me to part with the HF89 iron. When I
last had those trannies running as a high-powered 6550 Class AB P-P, it was
glorious. I was getting just about 80 W/Ch with a B+ that was, to the best
of my recollection, close to 550 V, with all solid-state regulation.
Without a tube rectifier drop, that's about what you end up with. The
topology was close to the stock Mullard circuit, with minor adjustments to
coupling caps and feedback trim at the phase margins, based on overload
recovery and square wave tests. Selling those trannies was a recognition
that I wouldn't have the time in the foreseeable future to build anything
like that again.
dbk
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: Sv: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 14:55:46 -0700
Source: Sound Digest Archive v02.n263
Douglas Purl wrote:
> On Wed, 25 Aug 1999, David B. Klein wrote:
>
> > You have no idea how hard it was for me to part with the HF89 iron. When I
> > last had those trannies running as a high-powered 6550 Class AB P-P, it was
> > glorious. I was getting just about 80 W/Ch with a B+ that was, to the best
> > of my recollection, close to 550 V, with all solid-state regulation.
> > Without a tube rectifier drop, that's about what you end up with.
>
> What a coarse oaf you continue to be. That voltage drop is sacred when it
> is produced by gaseous emission.
>
> Doug Purl
How ironic; it is usually by means of gaseous emissions that I advertise my
oafishness.
David
=========================================================================
From: rbales@gte.net (Ron Bales)
Subject: Re: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 14:57:27 GMT
Source: Sound Digest Archive v02.n263
On Wed, 25 Aug 1999 08:31:09, you wrote:
>A 07:52 AM 8/25/99 -0400, Ken Gilbert a écrit :
>>
>>>We know the 7027A is much like the rest of the 6L6 family and these
>>>points are within the ratings of the 7581.
Thanks for the responses, I guess I wasn't that clear when I explained
what I was thinking. Of course "what ROn is thinking" has never been
all that clear.
>>Ron, are you dead-set on the 7027? In every amp I have heard them in, the
>>Chineese (!) KT-66's are absolutely killer in tone.
Actually I'm looking to use 7581/6L6GC. Trying to find an operating
point that would suit the available trannies and voltages, I checked
under the 7027 tube data. You can hold the curves for these two up to
the light and not see any difference between them. But still, RCA
lists two different sets of operating points. Anyway I'm looking at
using an OP listed for the 7027 to run my7581s. Looks like it should
work.
>Is a beam power tube correctly called a pentode?
It's often enough called a pentode that nobody much holds it against
you. The Brits seem more precise and call them "Beam Tetrodes." Most
of the tube manuals just say "Beam Power Tube."
ROn
=========================================================================
From: rbales@gte.net (Ron Bales)
Subject: Re: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 15:06:19 GMT
Source: Sound Digest Archive v02.n263
On Wed, 25 Aug 1999 00:19:15 EDT, you wrote:
>
> Is this a case where I just have to build it and then tell everybody.
> >>
>Hi Ron,
>Experiment with different operating points before casting it in -er- nickel.
>The one tube I *know* is VERY sensitive to screen grid voltage is the
>6146 family. Different voltages can cause you to go from very sweet sound
>to a really dirty one.
>
>I've found some sensitivity like this with 6L6GC and 5881 based amps, but
>not to the same degree as the 6146.
Thanks, I'll be prepared to experiment. Heck, what's one more trim
pot. :) I may be overly worried about this going in, since this whole
beam tube thing is a little weird for me.
Oh, and while I've got you here, thanks for the great info on your
website. Been a huge help for me.
ROn
=========================================================================
From: Scott Grammer <tubedude@sunnetusa.net>
Subject: Re: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 17:12:01 -0400
Source: Sound Digest Archive v02.n263
"David B. Klein" wrote:
(snip)
> Is a beam power tube correctly called a pentode?
>
> dbk
No. It is a beam power tetrode. The EL34, BTW is a real pentode.
S.G.
- --
"To save every cog and wheel is the first
precaution of intelligent tinkering." -Aldo Leopold.
What if there were no hypothetical questions?
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: Sv: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 17:25:54 +0300
Source: Sound Digest Archive v02.n263
>Is a beam power tube correctly called a pentode?
No. It is not a genuine pentode , in the normal content.
The pentode does not "beam" the electron flow.
Pentodes has better transfering characteristics that the beam tube.
(Or beam pentode , as some calls it)
Most European power tubes are genuine pentodes , exept the KT series.
And I belive that about all , US made power pentodes , are the beam technology.
These are more effective , but the price is less linearity.
Do you plan to build a Beam power amp , David ? ;-)
- - Sincerely Kurt
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: Sv: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 17:30:28 +0300
Source: Sound Digest Archive v02.n263
>>We know the 7027A is much like the rest of the 6L6 family and these
>>points are within the ratings of the 7581
The 7027A , take some higher Anode Voltage , and dissipates a little more
that the 7581.
But all these tubes are very similar electrically:
807,6L6,KT 66, and some 30-40 other piecess.
- - Kurt
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: [JN] Unfamiliar Terrain, Pentodes.
Date: Wed, 25 Aug 1999 18:29:39 GMT
Source: Sound Digest Archive v02.n263
On Wed, 25 Aug 1999 07:52:50 -0400, Ken Gilbert <ride5000@ride.ri.net>
wrote:
>Ron, are you dead-set on the 7027? In every amp I have heard them in, the
>Chineese (!) KT-66's are absolutely killer in tone.
As long as we're taste-testing beam tetrodes, don't forget the 807.
- --dnb
=========================================================================
From: "Aaron Bohnen" <bohnen@unixg.ubc.ca>
Subject: Re: [JN] Unfamiliar Terrain, Pentodes. - favorite pentodes/tetrodes/etc...
Date: Wed, 25 Aug 1999 11:43:49 -0700
Source: Sound Digest Archive v02.n263
Hi everyone,
I might as well chime in here on the topic of beam tetrodes, pentodes,
etc. My personal all-time favorite pentode is the venerable 7591. I
really wish a good current version of that tube were available. Has
anyone else here noticed how musically "right" good samples of that tube
seem?
In the 6L6 family, my definite favorite is the Canadian General Electric
6L6WGB/5881 with the red bases, small bottles, and lots of extra spacers.
They were also marketed as Marconis and I have several of them labelled
this way. It's the same tube. These are not the most powerful 6L6 type
but they do sound great - certainly I like them the best of all those
I've tried in my upgraded HK Citation V.
best regards to all,
Aaron
___________________________________________________________
Aaron Bohnen email: bohnen@unixg.ubc.ca
- -Ph.D. Student, Civil Engineering Department, U.B.C.
- -website: http://www.civil.ubc.ca/home/bohnen
=========================================================================
From: "gtrmkr" <gtrmkr@wans.net>
Subject: Re: [JN] Unfamiliar Terrain, Pentodes. - favorite pentodes/tetrodes/etc...
Date: Wed, 25 Aug 1999 17:03:21 -0400
Source: Sound Digest Archive v02.n263
Aaron wrote (snipped):
> I might as well chime in here on the topic of beam tetrodes, pentodes,
> etc. My personal all-time favorite pentode is the venerable 7591. I
> really wish a good current version of that tube were available. Has
> anyone else here noticed how musically "right" good samples of that tube
> seem?
Agreed! I also think think the 7591 is a great tube, and it sounds even
better wired in triode. I've always wondered what a single-ened trioded 7591
would sound like...
Jim
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: [JN] Unfamiliar Terrain, Pentodes. - favorite pentodes/tetrodes/etc...
Date: Wed, 25 Aug 1999 21:17:41 GMT
Source: Sound Digest Archive v02.n263
On Wed, 25 Aug 1999 11:43:49 -0700, "Aaron Bohnen"
<bohnen@unixg.ubc.ca> wrote:
>In the 6L6 family, my definite favorite is the Canadian General Electric
>6L6WGB/5881 with the red bases, small bottles, and lots of extra spacers.
>They were also marketed as Marconis and I have several of them labelled
>this way.
I have a set of Canadian Marconi 6V6s, ex-military, in my Fender
Deluxe-Amp guitar amplifier, and they're outstanding. They have an
EL-84-like high-end shimmer that I've never heard from any other 6V6.
They also have cool-looking coke-bottle envelopes.
- --dnb
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From: "Michael (Mick)Maloney" <supra@cantech.net.au>
Subject: [JN] Unicores
Date: Thu, 11 Jan 2001 17:56:46 +0800
Source: Sound Digest Archive v02.n781
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Anyone had any experience or word of AEM Cores "unicore" transfomer
cores-similiar to c-cores.
MickM
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From: "John Hancock" <tubeman@mindless.com>
Subject: [JN] Unities and dipoles
Date: Wed, 15 Aug 2001 06:11:31 +0800
Source: Sound Digest Archive v02.n946
> My first intention when I bought the Unitys was to use them with an open
> bafle system like Thomas Dunker. I have built them, and i'm NOT satisfyed
> with them. The thing is that there is a HUGE resonance in the 3-400 Hz
> range. I have found out that this is partly because I have two rows of
> speakers, and they are spaced about 40 cm apart. Each row has 6 8" basses on
> each side, therefore each row has 12.
> The thing is that when I use only one row per side, which should prevent the
> resonance, it's stil there. At least this should be so if the resonance is
> caused by the distance between the two rows. But it's stil there. Another
> thing it might be is the sice of the bafle.
The resonance is due to the transmission line formed by the depth of the baffle, not the spacing of
the rows--though driver spacing of 40cm will cause lobing at 400Hz as well. The only way to avoid th
e resonance is to make the baffle depth smaller, but then that results in higher dipole cancellation
and higher cone excursion=more distortion. This problem plus the required equalization makes it dif
ficult to make a dipole bass module that will cover 30hz to 400 hz.
I'm working on a three way Unity for exactly this reason. A 24 inch square Unity will maintain good
directivity down to around 100Hz. Then dipole below that. I've been playing around with different fo
rm factors for the circular to square transition in the throat and with the shape of the midrange ho
les to reduce internal reflections and have had some success. It's amazing how much little things ma
tter in acoustics. I'll try to post some measurements to the LambdaDrivers list on www.groups.yahoo.
com tomorrow.
John
>
> Butt anyway. The thing we agreed on at the ATF was that it would be best if
> the Unitys were able to go down to about 100-150 Hz. And since the SPL-td1
> go down to 65 Hz this should be possible. Someone sugested building an
> extention to the home Unitys.
>
> Annyone have anny comments on this?
>
> I know Timo have plans to build new Unity copies with 2 10" drivers to. And
> he was talking about using a shape more like the SPL-td1's, and not a sqare
> opening. This doesn't seem to be to smart for me since I already have the
> originals made by Lambda. But it should be possible to make a good extention
> to the horns.
>
> The question is how to calculate the placement of the aditional drivers, and
> the shape of the extention.
>
> I have a lott more questions to, but they have to wait....
>
> Anders
>
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=========================================================================
From: Nicholas McKinney <nick@lambdacoustics.com>
Subject: [JN] Unity
Date: Tue, 22 Feb 2000 17:00:28 -0500
Source: Sound Digest Archive v02.n459
Hi Folks,
(Commercial plug about to follow)
For those that are interested, we have reached an agreement with Servodrive to
manufacture a home version of the Unity speaker.
www.servodrive.com
The final design details are still being worked on, but things are looking
really good as to the scaled down home model. I know that alot of you were
interested in this design, it holds alot of promise for home use.
Specifications, pricing, and options to be announced shortly. We are planning
a few variations of it, any input at the moment is most welcome.
Best regards,
Nicholas McKinney
Lambda Acoustics Inc.
www.lambdacoustics.com
=========================================================================
From: "John Hancock" <John_Hancock@swissre.com>
Subject: Re: [JN] Unity
Date: Wed, 23 Feb 2000 12:02:17 +0100
Source: Sound Digest Archive v02.n460
Nicholas McKiney wrote:
>For those that are interested, we have reached an agreement with
Servodrive to
>manufacture a home version of the Unity speaker.
This is great news. Here are some things I'd like to see:
1) Use high quality drivers. 4 Audax HM100Z0's (Tom mentioned these in a
previous post) mated with a TAD 2001 sounds excellent. I suppose you could
have several driver options to match different budgets. Not that I've got
a huge budget--just warped priorities.
2) Make it biamped. Padding the mid-treble unit 10dB or more to mate with
a woofer would be a crime.
3) Make it available in kit form--I have religious objections to buying
things already made.
4) How about making a deal with Tom to also sell the drivers for the
ContraBass? I've been trying to assemble the parts to make my own clone
drivers, but it is proving to be a monumental task.
Best of luck on the endeavor, John
=========================================================================
From: Timo Christ <carnivor@uni-bremen.de>
Subject: [JN] Unity Horn
Date: Wed, 20 Dec 2000 19:23:06 +0100
Source: Sound Digest Archive v02.n765
Hello,
well, Tom Danley's Unity horn design is bouncing around in my head, much
inspired by the pics on Nick's website too. I think i read all past
joe-net posts about it.
However, i still have some questions:
1) How do you calculate the point where the midrange exit holes are?
Their distance from the tweeter? Is this the distance from the tweeter
faceplate or its diaphragm? How exact does this have to be?
2) The angle of the glue joints of the four boards from which the horn
is made is 45 degrees? I have a drawing which specifies an angle of 48.7
degrees here. (John? you there?) I guess the 48.7 degrees is correct and
my 3d imagination impaired.
3) What is the area at the throat end where the compr. driver attaches?
4) The last third of the horn is "radiused", i imagined this to be a
smooth curve (part of a circle), but the nynoise2000 demo model and the
one pictured at the Lambda website appear to have a straight last third
with another angle. Correct? Are there any major benefits with a curved
mouth?
All of these questions relate to the domestic version of Unity, i.e. the
one that is sold by Lambda Acoustics.
I intend to build the same horn/lens but i want to use four 3/4"
midrange compression drivers and a Visaton DHT 9 horn tweeter. I already
have these drivers. The compression drivers will cover 500-5k and the
tweeter 5k on up. I expect great benefits from the coaxial layout
already but of course i want as much of the timealignement as possible,
too. Will probably be difficult at a 5kHz crossover frequency.
The large vertical distance between mid + tweet in my present system
really gets on my nerves and the tweeter positioned back on the midrange
horn surely has its share of diffraction problems.
BTW, are there some Unity systems from Lambda already in use?
I for one would love some user reports and pictures of Unity systems.
:-)
Best Regards and have a nice Xmas!
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: "John Hancock" <John_Hancock@swissre.com>
Subject: RE: [JN] Unity Horn
Date: Fri, 22 Dec 2000 15:48:56 +0100
Source: Sound Digest Archive v02.n768
Tinno wrote:
>1) How do you calculate the point where the midrange exit holes are?
>Their distance from the tweeter? Is this the distance from the tweeter
>faceplate or its diaphragm? How exact does this have to be?
Ideally you would "time align" them. To do that you need to know the
acoustic center of the drivers at the crossover frequency. There is no easy
way to guess this that I know of. All the reactances in the driver create
phase shift which will move the effective acoustic center away from the
driver diaphragm. If you can measure the acoustic center, then the path the
acoustic waves travel from the acoustic centers of the drivers through the
horn need to be offset by the amount of phase shift introduced by the
crossover at the crossover frequency. For example, 90 degrees of phase
shift at 5kHz is approximately 343m/s / 5000Hz * 90degrees / 360 degrees =
1.7cm. The easiest way to do this is perhaps to mount the drivers to the
horn in such a way that you can move the midrange exit holes around, feed
the horn an impulse signal and then move the midranges around until the
impulse response looks good. Tom Danley probably modeled everything using
his fancy programs and only needed one try to get it right, but for the
rest of us, there is no substitute for trial and error.
>2) The angle of the glue joints of the four boards from which the horn
>is made is 45 degrees? I have a drawing which specifies an angle of 48.7
>degrees here. (John? you there?) I guess the 48.7 degrees is correct and
>my 3d imagination impaired.
Unless my trigonometry is failing me, everything should be 45 or 30
degrees.
>3) What is the area at the throat end where the compr. driver attaches?
Depends on the time-alignment thing and the flare of the horn. The home
Unity is a 60x60 degree pyramid. You don't have to do it this way, though.
You can adjust the amount of horn loading you get by changing the angle. I
suspect that with a 5kHz crossover point and a large distance between the
acoustic center of your midranges and the exit of your midranges that the
midrange exits will have to be located pretty close to the tweeters, in
which case, you'd have to have a fairly narrow horn angle (less than 60x60)
to get horn loading down to 500Hz. Having a large tweeter radius will help,
though. How big is it?
>4) The last third of the horn is "radiused", i imagined this to be a
>smooth curve (part of a circle), but the nynoise2000 demo model and the
>one pictured at the Lambda website appear to have a straight last third
>with another angle. Correct? Are there any major benefits with a curved
>mouth?
I think this is to reduce diffraction effects. There should be a benefit to
a curved mouth, if done at the right rate. However, I'm not sure the
improvement is enough to warrant the extra manufacturing complications.
>BTW, are there some Unity systems from Lambda already in use?
>I for one would love some user reports and pictures of Unity systems.
Unfortunately, no luck there. I've been waiting for what seems an eternity
to have mine delivered. I think Nich has decided to focus on the retail
market and has gotten distracted from the DIY business at least for the
time being. I can't really blame him. Business-wise it makes a lot of sense
and I wish him the best.
John
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] Unity Horn
Date: Fri, 22 Dec 2000 18:50:33 -0600
Source: Sound Digest Archive v02.n768
John Hancock wrote:
> Tinno wrote:
>
> >1) How do you calculate the point where the midrange exit holes are?
> >Their distance from the tweeter? Is this the distance from the tweeter
> >faceplate or its diaphragm? How exact does this have to be?
>
> Ideally you would "time align" them. To do that you need to know the
> acoustic center of the drivers at the crossover frequency. There is no easy
> way to guess this that I know of. All the reactances in the driver create
> phase shift which will move the effective acoustic center away from the
> driver diaphragm. If you can measure the acoustic center, then the path the
> acoustic waves travel from the acoustic centers of the drivers through the
> horn need to be offset by the amount of phase shift introduced by the
> crossover at the crossover frequency. For example, 90 degrees of phase
> shift at 5kHz is approximately 343m/s / 5000Hz * 90degrees / 360 degrees =
> 1.7cm. The easiest way to do this is perhaps to mount the drivers to the
> horn in such a way that you can move the midrange exit holes around, feed
> the horn an impulse signal and then move the midranges around until the
> impulse response looks good. Tom Danley probably modeled everything using
> his fancy programs and only needed one try to get it right, but for the
> rest of us, there is no substitute for trial and error.
Lest you think too highly of my programing abilities, in reality, I can model
parts of the Unity but I don't have a model which describes the whole thing. My
approach was also "trial and error" sort of.
I built and measured the "first guess" and THEN tried to refine the
relationships with acoustical or electrical theory.
With further prototypes the model got refined and the understanding of its
operation improved.
You must have the drivers aligned both in time and phase (it is possible to be
in phase but N cycles off in time) to make it work properly. The ranges have to
be adding together where the dimensions are less than 1/4 wl or spatial
problems result. You will need some test gear which can see this stuff because
it is unlikely you will find the dimensions by trial and error and when its
"right" it works very well.
>
>
> >2) The angle of the glue joints of the four boards from which the horn
> >is made is 45 degrees? I have a drawing which specifies an angle of 48.7
> >degrees here. (John? you there?) I guess the 48.7 degrees is correct and
> >my 3d imagination impaired.
To make such a horn (where all 4 parts are the same) requires compound angle
cuts.
For a 60 deg horn angle, the blade angle is 37.7 deg and crosscut angle 26.5
deg.
If you are going to cut these out, do yourself a favor and make a cutting board
jig.
This is a board about 1/2 inch thick with strips attached that ride in the saw
table slots.
This sliding table then has a stop on it to hold the stock at the right angle
and a hold down to keep the wood from moving on the jig.
Remember, the exact angle of the horn wall angle is much less important than
having all the parts the same.
>
>
> Unless my trigonometry is failing me, everything should be 45 or 30
> degrees.
>
> >3) What is the area at the throat end where the compr. driver attaches?
>
The actual throat for a 1" exit driver is usually equal to between a 5/16 and
3/8 inch diameter circl