Sound Practices Mailing List Files - Volume 1
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Safe battery biasing (was: 417A operating points, et al )
Date: Tue, 16 Jun 1998 09:44:45 +0200
Source: Sound Digest Archive v01.n311
- ----------
> De : Dave Stagner <dstagner@icarus.net>
> Date : lundi 15 juin 1998 23:27
> Like i said, i don't want to do battery bias on my friend's amp for
> reliability reasons. I won't always be there to fix it, and he doesn't
> understand electronics.
Hello,
Doing a lot of different experiment with my monotube (WE437) amplifier I
felt the need to experiment a cathod biasing by battery.
I use lithium battery (something like 750mAH if I remember correctly)
I tried different solutions, with a capacitor in parallel or without.
Finally I used a capacitor in parallel.
As the current (between 20 and 30 mA)through the tube was also the surge
current I noticed also that it was too much for the small batteries I used,
they were heating a lot. You could say to me that the solution should be to
use larger batteries but I cannot use larger batteries here. I have no
remaining place under the chassis because of my my lead counterplates
supporting the tubes :-)
First solution:
I put a resistor to derive a part of the current through the tube so the
surge current is kept within reasonable limits. Bad idea,the bias point
varied a lot and during a very long time when heating the amp and the
sounds changed a lot too.
Second solution:
I had the idea that I could use silicon rectifiers in parallel with the
lithium battery.
I wanted the surge current too stay around 10 mA so I have to derived
around 20 mA.
I draw the current voltage of the silicon rectifiers. This indicated to me
that for the voltage (in operation) of the lithium battery I have too put
several silicon rectifiers in series to obtain the same voltage (don't
remember how many I think it is 2).
The silicon rectifiers are used in the curved part (low current) of their
characteristic curve. When the voltage of the battery rises, more current
is derived through the silicon rectifiers. When the voltage of the battery
decreases, less current is derived through the silicon rectifiers. This
insure a pretty good stabilization of the battery voltage and of the bias
point of the tube.
Also when the amp is off, the current decreases rapidly through the silicon
rectifiers and the lithium batteries keep their surge.
Advantages:
There is no more change in the bias point of the tube when heating the amp.
The lithium + the capacitor damp every noise from the silicon rectifiers.
This is very safe, the battery state of surge is very constant with time.
You don't have to bother about the battery anymore.
For the moment I keep using that solution with greatest satisfaction.
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: Hartmut <Hartmut.Quaschik@mch.sni.de>
Subject: Sakuma Interstage question
Date: Mon, 14 Sep 1998 16:43:43 +0200
Source: Sound Digest Archive v01.n423
Joe-Netters,
a friend who visited Sakuma a few weeks ago,
got a Tamura A4714 interstage driver xfr, 10k:10k+10k
or 10k:40k center tapped, 20mA DC
as he has got only a single he asks, how he can get
a second one (the Tamura page does not list that part
number), or if anybody on the list wants to sell or buy
a single piece.
regards,
Hartmut from Munich
=========================================================================
From: Andrej Deticek <andrej.deticek@siol.net>
Subject: Re: Sakuma Interstage question
Date: Tue, 15 Sep 1998 08:59:52 +0200
Source: Sound Digest Archive v01.n423
Hartmut wrote:
>
> Joe-Netters,
>
> a friend who visited Sakuma a few weeks ago,
> got a Tamura A4714 interstage driver xfr, 10k:10k+10k
> or 10k:40k center tapped, 20mA DC
> as he has got only a single he asks, how he can get
> a second one (the Tamura page does not list that part
> number), or if anybody on the list wants to sell or buy
> a single piece.
>
> regards,
> Hartmut from Munich
Hello Hartmut,
Tamura pages at Sunaudio do list such transformers. However, either the
quoted part number is wrong, or the described winding impedances do not
match the type number A-4714.
Such transformers are listed under the "Input Transformers" heading:
http://www2.big.or.jp/~sunaudio/tamura/input.html
Actually, this page lists input, interstage and line output
transformers.
There is a typo on this page regarding the turns ratio of A-4714, which
is *not* 1:1.
Type A-4714 is a SE line output transformer with primary winding
suitable as 5K load and secondary windings of 600, or 150, or 6 ohm. At
60 mA permissible primary current Sakuma uses it to load tubes like
EL-34, 300B, 50, KT-66, etc., as line stage or low power output
transformer.
Sunaudio price for Tamura A-4714 was a year ago 9660 yen (1$ at about
Yen 135 - not a bad price!). As their prices don't change frequently, it
is likely to have stayed the same. Koji at Eifl charges $ 96 - the price
is listed on his web pages. Sunaudio are nice to deal with and they take
Visa since June.
Your friend could be surprised how quickly one can get such a
transformer from Japan...
Regards,
Andrej from Ljubljana (Laibach)
=========================================================================
From: Carter Hendricks <carterh@crl.com>
Subject: Sakuma-like
Date: Mon, 1 Dec 1997 12:33:51 -0800 (PST)
Source: Sound Digest Archive v01.n122
From the basement of the St Louis public library:
This interesting schematic--
Interesting early-50's Sakuma-like [oh, except Sakuma-san
was like about 10] transformer input PP 6V6 IT PP807
"booster" amp:
Thordarson transformers----------------------------------
T20A05
T20D78 [Allied '57 says 40 mA 4:1 pri to 1/2 sec]
T22s78 [ " " " 3300 CT]
Secondaries of the T20A05 loaded with 2 100K pots [stereo!]
Anyone have a transformer catalog with more info on the
input & IT transformers? These are probably seriously
bandwidth shy but it is an interesting amp, in a pentode
sort of way, and worth some study...
--Carter
=========================================================================
From: AirGapped@aol.com
Subject: Re: Sakuma-like
Date: Mon, 1 Dec 1997 16:13:07 -0500 (EST)
Source: Sound Digest Archive v01.n122
In a message dated 97-12-01 16:03:14 EST, you write:
<<
This interesting schematic--
Interesting early-50's Sakuma-like [oh, except Sakuma-san
was like about 10] transformer input PP 6V6 IT PP807
"booster" amp:
>>
Not to detract from the interest you have in this amp...but another
interesting application was the early RCA give away schematic complete with
specs for all the tranneys used in the circuit. This was published in
SP...forget the issue. Does anyone find this an interesting circuit???
Mike
=========================================================================
From: Thomas Danley <tom@ppci.com>
Subject: Re: Salvager or parts in Chicago area
Date: Wed, 21 Jan 1998 16:05:41 -0600
Source: Sound Digest Archive v01.n167
dhome@creo.com wrote:
>
> I am delayed in Chicago for several days. Any residents on this list that can
> recommend an interesting place(s) for a Joenetter to go? A good electronic parts
> /salvager place, stereo store friendly to DIYers(a rare thing indeed), or
> anything else of audio/music interest. I should have brought a nice 10Y to gaze
> at! Help!!
>
> Regards, David
Hi
You might want to go to Triode electronics (on Roscoe I think but it
should be in the phone book) for tube stuff. Also Saturday Audio
exchange @ 2919 N clark for used eqpt (open Thursday night and
saturday).
Have fun.
Tom
=========================================================================
From: dhome@creo.com
Subject: Salvager or parts in Chicago area
Date: Wed, 21 Jan 98 10:33:39 PST
Source: Sound Digest Archive v01.n167
I am delayed in Chicago for several days. Any residents on this list that can
recommend an interesting place(s) for a Joenetter to go? A good electronic parts
/salvager place, stereo store friendly to DIYers(a rare thing indeed), or
anything else of audio/music interest. I should have brought a nice 10Y to gaze
at! Help!!
Regards, David
=========================================================================
From: Cheng Yunhong <chengyh@ramm.neu.edu.cn>
Subject: sample
Date: Thu, 27 Nov 1997 09:44:42 +0800 (CST)
Source: Sound Digest Archive v01.n120
Dear Publisher & Editor,
I am an audiophile and journalist for some audio magazines in China. It is
said SOUND P. is a very good magazine, or say special than others.
If you could mail me one sample issue, it is heartly appritiated. And may
we become cyber friends?
Thanks a lot!
Gu Tao,MSc
Editor
P.O.Box 267
Northeast Univ.
Shenyang 110006
PRC
=========================================================================
From: tubesguy@mail.execpc.com (Patrick Currie)
Subject: Sandy Ong?
Date: Mon, 5 Oct 1998 17:31:33 -0500
Source: Sound Digest Archive v01.n442
>Also on the topic of the Hiraga crossover, would anyone know how I could
>contact Sandy Ong? Robert Root was telling me on Sunday that Sandy has a
>few refinements to the design that allow for a little fine-tuning. TIA -
>Pat
>
>Pat Currie (tubesguy@execpc.com)
Pat Currie (tubesguy@execpc.com)
=========================================================================
From: STEVE CORNETT <SCORNETT@usagroup.com>
Subject: Sansui 1000
Date: Wed, 20 May 1998 07:27:04 -0600
Source: Sound Digest Archive v01.n285
Thought I'd pass along that there is a Sansui model 1000 receiver at
auction on EBAY. Ends today. Current bid is $51. Might be worth it just
for the trannies, but looks to be in very nice shape.
=========================================================================
From: Tim Reese <reese@nmr.MGH.harvard.EDU>
Subject: Re: Sansui 1000
Date: Wed, 20 May 1998 09:23:58 -0400 (EDT)
Source: Sound Digest Archive v01.n285
Steve wrote:
>Thought I'd pass along that there is a Sansui model 1000 receiver at
>auction on EBAY. Ends today. Current bid is $51. Might be worth it just
>for the trannies, but looks to be in very nice shape.
I bought a junker (complete except for 7591s) for transformers for $10 at the
MIT flea - NB that the power transformer is a voltage doubler at about 240VAC
- - use for that 6Y6 project? You could likely get your money back by selling
the 7591s if you wanted to part it out.
Seems a shame to junk a working unit tho - I hear they sound pretty good
for mass-market tube rcvrs (on a par w/ the 500 or 340B?).
I also have a dial glass, front plate and knobs if anyone needs them.
cheers tr
- ----------------------------------------------------------------------
Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu
=========================================================================
From: "Lee, Doo J" <dlee@pica.army.mil>
Subject: RE: Sansui 1000
Date: Wed, 20 May 1998 09:46:11 -0400
Source: Sound Digest Archive v01.n285
The Sansui 1000 in question does NOT use the 7591s. I was told that it
uses the PL36 or 25E5 output tubes. The later 1000A uses the 7591s.
Don't know if the output xformers are the same. Personally, I like the
Sansui 1000A better than the Fisher 500B/C.
djl
> ----------
> From: Tim Reese[SMTP:reese@nmr.MGH.harvard.EDU]
> Sent: Wednesday, May 20, 1998 9:23 AM
> To: sound@deliverator.io.com
> Subject: Re: Sansui 1000
>
> Steve wrote:
> >Thought I'd pass along that there is a Sansui model 1000 receiver at
> >auction on EBAY. Ends today. Current bid is $51. Might be worth it
> just
> >for the trannies, but looks to be in very nice shape.
>
> I bought a junker (complete except for 7591s) for transformers for $10
> at the
> MIT flea - NB that the power transformer is a voltage doubler at about
> 240VAC
> - use for that 6Y6 project? You could likely get your money back by
> selling
> the 7591s if you wanted to part it out.
>
> Seems a shame to junk a working unit tho - I hear they sound pretty
> good
> for mass-market tube rcvrs (on a par w/ the 500 or 340B?).
>
> I also have a dial glass, front plate and knobs if anyone needs them.
>
> cheers tr
> ----------------------------------------------------------------------
> Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu
>
=========================================================================
From: RALPH POWER <POWER.RALPH@epamail.epa.gov>
Subject: Sansui 1000A transformer leads
Date: Mon, 17 Nov 1997 13:27:30 -0500
Source: Sound Digest Archive v01.n112
Hi All,
Does anyone know the lead outs for the Sansui 1000A output transformers ?
The primary has blue, orange and yellow leads, and the secondary has blue, black,
and yellow leads.
I understand that these were the ones used in Eric Barbour's "Single-ended Glory"
article for Glass Audio.
If someone knows the lead outs or can reference them in the GA article, this
information would be much appreciated.
Thanks for any info,
- Ralph
=========================================================================
From: "Bottlehead" <Bottlehead@prodigy.net>
Subject: Re: Sansui 1000A transformer leads
Date: Tue, 18 Nov 1997 08:42:56 -0800
Source: Sound Digest Archive v01.n114
Hey Ralph,
Can't remember the lead out, but just take a meter and measure resistance.
Anybody want to buy a pair of these? I'll sell mine for $75 the pair plus
shipping.
Doc B.
>
> Hi All,
>
> Does anyone know the lead outs for the Sansui 1000A output transformers ?
>
> The primary has blue, orange and yellow leads, and the secondary has
blue, black,
> and yellow leads.
>
> I understand that these were the ones used in Eric Barbour's
"Single-ended Glory"
> article for Glass Audio.
>
> If someone knows the lead outs or can reference them in the GA article,
this
> information would be much appreciated.
>
> Thanks for any info,
>
> - Ralph
=========================================================================
From: RALPH POWER <POWER.RALPH@epamail.epa.gov>
Subject: Re: Sansui 1000A transformer leads -Reply
Date: Wed, 19 Nov 1997 16:32:44 -0500
Source: Sound Digest Archive v01.n115
Hi Edward,
I said:
>Does anyone know the lead outs for the Sansui 1000A output transformers ?
You said:
>Ralph, I remembered having wrote these down as :
>primary B plus orange
>plates yellow&blue.
>secondary yellow 16
> blue 8
> black common
If this is true then I have been running my 8 ohm Lowthers 2Cs off the 16 ohm taps !
Anyone care to comment on the effects of this on the sound quality I'm receiving.
I'll change them over to the 8 ohm taps right away.
Thanks much for the info Edward,
- Ralph
=========================================================================
From: Rick Francis <rfranci@uoft03.UTOLEDO.EDU>
Subject: Re: Sansui 1000A transformer leads-- using ohmmeter on OPT=magnetizing?
Date: Tue, 18 Nov 1997 13:43:57 -0500 (EST)
Source: Sound Digest Archive v01.n114
On Mon, 17 Nov 1997, RALPH POWER wrote:
>
> Does anyone know the lead outs for the Sansui 1000A output transformers ?
>
Some time ago I was told not to use an ohmmeter on an OPT for fear of
"magnetizing" it. Is this actually a problem?
I hope not. It seems the easy obvious way to find if the primary is open
on an OPT, as well as the easy way to find which is the center tap, just
by comparing measurements -- which would be one answer for Ralph. I do
this all the time, haven't been aware of screwing anything up yet.
Rick
=========================================================================
From: "Frank Deutschmann" <fdeutsch@bfm.com>
Subject: Re: Sansui 1000A transformer leads-- using ohmmeter on OPT=magnetizing?
Date: Wed, 19 Nov 1997 13:29:55 -0500
Source: Sound Digest Archive v01.n115
On Nov 18, 1:43pm, Rick Francis wrote:
> Some time ago I was told not to use an ohmmeter on an OPT for fear of
> "magnetizing" it. Is this actually a problem?
I doubt that this would be a problem at all for any OPT; certainly not for SE
OPT's (there's something seriously wrong if your meter is pushing more than a
few mA on a resistance measurement), and the very small current should not be
a problem for PP OPTs, either.
However, ungapped input and interstage transformers, particularly those of
the Nickel flavor, might be an entirely different story: it probably would
not be difficult at all to magnetize one of those pups with even a few mA of
DC. (The results of a magnetized input or interdtage xformer would not be
pretty, and de-magnetizing it would be a PITA.) Best use a signal generator
set to a very low amplitude for testing these critters!
- -frank
=========================================================================
From: Grego Sanguinetti <grego@latticesemi.com>
Subject: Re: Sansui 1000A transformer leads-- using ohmmeter on OPT=magnetizing?
Date: Wed, 19 Nov 1997 17:09:42 -0800 (PST)
Source: Sound Digest Archive v01.n115
> DC. (The results of a magnetized input or interdtage xformer would not be
> pretty, and de-magnetizing it would be a PITA.) Best use a signal generator
> set to a very low amplitude for testing these critters!
>
> -frank
I use a little handheld LCR meter. A wonderfull tool to have when dumpster
diving in transformer waters. It uses a 1kHz AC(obviously) signal.
On the other hand I have never tried to measure an interdtage xformer[sic]
but I can guess why it's an X rated former....
- -grego (guess I'm just in a silly mood today)
=========================================================================
From: Thomas Danley <tom@ppci.com>
Subject: Re: Sansui 1000A transformer leads-- using ohmmeter on OPT=magnetizing?
Date: Wed, 19 Nov 1997 17:45:45 -0600
Source: Sound Digest Archive v01.n115
> On Nov 18, 1:43pm, Rick Francis wrote:
> > Some time ago I was told not to use an ohmmeter on an OPT for fear of
> > "magnetizing" it. Is this actually a problem?
Hi all
No, most transformers one is apt to run into in audio (and ac power too)
are made of "soft" magnetic materials which conduct magnetism well but
do not stay magnetised (except for a tiny residual flux) once the
current is removed. AC Power and Tube output transformers are generally
made of one of several types of grain oriented silicon steel which does
not have the highest permeability (typically 1000-4000 depending on its
configuration and level) but for its cost, has the highest maximum flux
capacity.
There are better materials (depending what you are trying to acomplish)
but they are all more expensive.
For example a toroid made from sil-steel can operate happily at peak
flux's of 16-18 KG (where an EI core of the same material is 12-16 KG)
but a toroid of Supermendur can go up to 20-22 KG (although its about
10-20X more expensive).
For output transformers, there are two different low frequency cutoffs,
one for small signals set by the inductance and load/source impedances
(generally for good sized output Xfm's is way way below 20 HZ) and the
other is set by the maximum flux (before saturation)and frequency.
The latter acts as a 6 dB/oct slope limiting the maximum voltage that
can be produced per turn.
I am relitivly new to the list and was wondering does any one here wind
there own transformers?
Also, is the "joelist" available in the digest format?
Best Regards,
Thomas Danley
Intersonics Technology Corp
=========================================================================
From: Rick Francis <rfranci@uoft03.UTOLEDO.EDU>
Subject: RE: Sansui 1000 -- good OPTs?
Date: Wed, 20 May 1998 10:18:28 -0400 (EDT)
Source: Sound Digest Archive v01.n285
On Wed, 20 May 1998, Lee, Doo J wrote:
> The Sansui 1000 in question does NOT use the 7591s. I was told that it
> uses the PL36 or 25E5 output tubes. The later 1000A uses the 7591s.
> Don't know if the output xformers are the same. Personally, I like the
> Sansui 1000A better than the Fisher 500B/C.
>
> djl
If anyone knows about this Sansui 1000, I'd like to know. A local guy is
wanting to sell one for $60, I think, and it is this 25E5 or whatever
tube. I was told this is electrically identical to a 6146 -- can anyone
verify this?
Rick
=========================================================================
From: Rick Francis <rfranci@uoft03.UTOLEDO.EDU>
Subject: Sansui 1000 OPTs -- info?
Date: Mon, 20 Oct 1997 11:34:40 -0400 (EDT)
Source: Sound Digest Archive v01.n076
Guy I know has a Sansui receiver --maybe SA-1000? Anyway, it's an FM
receiver, model something-1000. I've heard the OPTs in this unit are
quite good -- but for what?
Are the output tubes 6146? (The owner doesn't know, lives almost an hour
away, is actually selling it for another guy, etc.) I'm trying to figure
what the primary impedance is on these pups. Any help appreciated.
Rick Francis, rfranci@uoft03.utoledo.edu
=========================================================================
From: RALPH POWER <POWER.RALPH@epamail.epa.gov>
Subject: Sansui 1000 OPTs -- info? -Reply
Date: Mon, 20 Oct 1997 15:13:31 -0400
Source: Sound Digest Archive v01.n076
Hi Rick,
You asked for Sansui 1000 OPTs info.
I got a set of what I believe are these same trannies from Ed Bellici recently.
They are Sansui and say "1000" on the back in white.
Ed says they are around 10k and are made by the forerunners of the Tamura
transformer company.
He says that they are the same ones used in the "Single Ended Glory" article in
Glass Audio magazine by Eric Barbour.
Eric used these somewhat chunky PP outputs in a single ended 2A3(?) amp with
good success because they were able to take some measure of unbalanced DC
without saturation. They have some kind of alternating laminations too(?).
All of the the above subject to my memory, which has been known to be wrong.
I am going to use them in a PP 45 amp, Lundahl interstage driven by a SE 5842, if
I can finish getting the parts together, maybe in a couple of weeks.
I'll report to all when I start to get some sound (hopefully).
Hope this info helps, maybe Ed can confirm....
- Ralph
=========================================================================
From: "Mr.Nightmare" <cros1605@together.net>
Subject: sansui au-5500
Date: Wed, 7 Jan 1998 11:15:47 -0500
Source: Sound Digest Archive v01.n155
just a quick question... i finally ogt rid of that nasty little jvc mini
system (okay it wasn't that bad, but it wasn't that good). My new/old toy
is a sansui au5500 integrated amp. i was wondering if any body had any
thought about this old beast (the channel seperation is much better, than
the jvc... used to have one speaker next to me the other next to the sys...
big difference and the tone defeat is nice)... And if turns out that this a
rotten piece of iron i only paid $50 for it...
- -bac
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: Sansui reciever
Date: Tue, 23 Sep 1997 10:46:34 -0700
Source: Sound Digest Archive v01.n037
Dale.Simon@pscmail.ps.net wrote:
>
> Hey all,
>
> I have 70s vintage Sansui reciever (forget the model but it's
> solid state). Anyway, it has an annoying hiss that I believe is
> due to the output stage, as it is not dependant upon volume, and
> only rears its head after the unit has warmed up. Does anyone
> have any good suggestions where to start looking (leaky cap?),
> or is the hiss just a characteristic of that unit?
> Thanks ahead,
>
> Dale
Dale,
Yeah, I've got one like that I bought at a garage sakle for three bucks
for one of the kids. Never bothered to try to fix it, but I would track
down the first transistor stage where the hiss occurs and try replacing
the transistor. It may have a stage of gain following the volume
control, but prior to the final amplifier. This is where I would
look first. You could use a cap to short out the hiss signal at the
input of the final amplifier section, then the collector of the
preceding stages to determine in which stage it is occurring. It may be
a bit harder to find if it is occurring in a stage that is in the
feedback loop of the final amplifier. I would somehow doubt that the
hiss would be occurring in an output transistor.
Dan Marshall
=========================================================================
From: Dale.Simon@pscmail.ps.net
Subject: Sansui reciever
Date: Tue, 23 Sep 1997 11:25:00 -0500
Source: Sound Digest Archive v01.n037
Hey all,
I have 70s vintage Sansui reciever (forget the model but it's
solid state). Anyway, it has an annoying hiss that I believe is
due to the output stage, as it is not dependant upon volume, and
only rears its head after the unit has warmed up. Does anyone
have any good suggestions where to start looking (leaky cap?),
or is the hiss just a characteristic of that unit?
Thanks ahead,
Dale
=========================================================================
From: Finn Hammer <f-hammer@post5.tele.dk>
Subject: Santa Fe Bugle?
Date: Sat, 08 Aug 1998 14:39:43 +0200
Source: Sound Digest Archive v01.n381
Reference has frequently been made to this Periodical.
What is the Santa Fe Bugle, really?
Finn
- --
HOME OF
Tractrix Horns, Tube Amps,
Fieldcoil Loudspeakers and Computer Graphics
http://home5.inet.tele.dk/f-hammer/
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: Re: Santa Fe Bugle?
Date: Sat, 8 Aug 1998 13:27:39 -0600 (MDT)
Source: Sound Digest Archive v01.n382
On Sat, 8 Aug 1998, Finn Hammer wrote:
> Reference has frequently been made to this Periodical.
>
> What is the Santa Fe Bugle, really?
A trendy desert magazine that has prospered by creating endlessly cresting
waves of enthusiasm for new products, each a higher peak than the last,
until finally, tsunamied with advertising fees, Stereophile bought the
bank. To Joenetters, an audio oasis where the drinks are often sandy.
Doug Purl
=========================================================================
From: "Lynn T. Olson" <lynno@teleport.com>
Subject: Re: Santa Fe Bugle & Y2K?
Date: Sun, 9 Aug 1998 11:48:35 -0700
Source: Sound Digest Archive v01.n382
Two clarifications:
Y2K is the notorious Year 2000 software bug. This is no joke, there are
tens of thousands of "embedded controllers" (no-keyboard no-display PC's in
a steel can) in electric switchyards, power station controllers, air
traffic control, elevator controllers, etc etc. Those damn microprocessors
and their slapdash assembly language code are everywhere, and no, software
managers only started to pay serious attention to the problem in the last
few years (I said pay attention, not devote resources to correct them!).
Some things will go a little goofy after Jan 1 2000, only we don't know
which ones; it will be random and spread all over society.
For more info, see Ed Yourdon (yes, the inventor of structured programming) at:
http://www.yourdon.com/index.htm
Note that Ed is not exactly Chicken Little or a survivalist in the hills of
Montana: he's a well-respected programmer going back for several decades.
>Reference has frequently been made to this Periodical.
>
>What is the Santa Fe Bugle, really?
A running joke of mine that I started back in my Positive Feedback days (I
still write for them, mostly the more political stuff). I once wrote a
column for Positive Feedback obliquely referring to the Stereophile as the
"Santa Fe Bugle" (similar to small-town newspaper ... and Santa Fe, New
Mexico, is indeed a small town). The Absolute Sound received the name of
the "Sea Cliff Herald", since that's where Harry Pearson lives, and that
also has the sound of a small-town newspaper.
Silly jokes, perhaps, but making the point that there are no "authoritative
journals" in our line of work. For some odd reason, many people think that
the magazine with the biggest circulation is the most authoritative.
All it actually means is they have the biggest ad budget. (In the magazine
business, advertisements pay for about 60 to 90% of the costs of the
magazine ... especially true for 4-color printing, which is very very
expensive. The higher the circulation, the more you can charge for ads, and
the more advertisers you attract. Same as TV broadcasting. The one who pays
the piper calls the tune.)
Lynn T. Olson
Editor, Valve & Tube News
E-mail: lynno@teleport.com
Ariel Speaker Page: http://www.teleport.com/~lynno/Ariel.htm
=========================================================================
From: Rhthatcher@ra.rockwell.com
Subject: Sarah McLachlan Vinyl
Date: Mon, 20 Apr 1998 17:10:58 -0400
Source: Sound Digest Archive v01.n258
Where can i get Sarah McLachlan music on vinyl?
randy
=========================================================================
From: tubesguy@mail.execpc.com (Patrick Currie)
Subject: Re: Sarah McLachlan Vinyl
Date: Mon, 20 Apr 1998 18:56:20 -0500
Source: Sound Digest Archive v01.n258
>Where can i get Sarah McLachlan music on vinyl?
>
>
>randy
Music Direct in Chicago has Sarah on, I believe, Classic Records. The
Freedom Sessions and her first big hit CD on one double album vinyl set. -
Pat
Pat Currie (tubesguy@execpc.com)
=========================================================================
From: Jeff Mai <jmai@fn.net>
Subject: Sato's Horn
Date: Mon, 27 Apr 1998 00:03:39 -0600
Source: Sound Digest Archive v01.n262
Anyone have any plans or additional information on Sato's horn? I've seen
the pictures on the horn speaker home page but would like to get more info
on actual construction.
Any help would be greatly appreciated.
Thanks!
Jeff
=========================================================================
From: "alfred trower" <sedht@hotmail.com>
Subject: Re: Save the shaded dogs sale...
Date: Wed, 17 Dec 1997 14:22:47 PST
Source: Sound Digest Archive v01.n137
Ralph Power wrote:
>Hi all,
>
>For all you vinyl heads out there, I just found out that Classic
Records at
> (800) 457-2577 is having a "Save the Shaded Dogs" sale of ten selected
RCA
>Living Stereo reissue classical LPs for $9.99 each. Normally $30.00
each.
>Shipping is $6.00 per order.
>
Tower Records Annex on East 4th St in the village (NYC) had all of the
Living Stereo reissues on sale for $15, or $10 each if you buy 10. I
picked up Scherezade/Reiner and will probably return before the end of
the year to buy 10 more. They aren't quite as good as the original
issues, but they do sound pretty good. High quality vinyl and very
quiet surfaces.
Good listening,
Al
Alfred Trower
Consultant, Client/Server Systems
Supply Chain Specialist
- ----------------------------------
"The higher we soar the smaller we appear to
those who cannot fly." Friedrich Wilhelm Nietzsche
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: RALPH POWER <POWER.RALPH@epamail.epa.gov>
Subject: Save the shaded dogs sale...
Date: Wed, 17 Dec 1997 16:23:11 -0500
Source: Sound Digest Archive v01.n137
Hi all,
For all you vinyl heads out there, I just found out that Classic Records at
(800) 457-2577 is having a "Save the Shaded Dogs" sale of ten selected RCA
Living Stereo reissue classical LPs for $9.99 each. Normally $30.00 each.
Shipping is $6.00 per order.
The albums are: LSC 2135, 2323, 2336, 2405, 2423, 2450, 2456, 2465, 2500, 2541
You can look up these titles on the Classic Records website at :
http://www.classicrecs.com/catlclas.htm
Their rights to make and sell these 10 selections expire at the end of this year and
any unsold albums must be destroyed !
There are also ten rock selections on sale also, but I didn't ask about them.
FYI,
- Ralph
=========================================================================
From: ecash@moneywizards
Subject: Saving our environment is GOOD! :0)
Date: Thu, 29 Jan 1998 01:07:21 -0600
Source: Sound Digest Archive v01.n174
############################################################
This mailing is sent conforming to a strict ethical code. If you wish to be removed from our mailing
list please press reply and type REMOVE in the subject area and press send.
############################################################
Dear friend:
Finally a duplication system that really WORKS for your own home business that does have a huge env
ironmental impact.
Please listen to to the message at 716-720-6340 it very well may change your life financially.
Have a pen handy!
Please contact me if you have any questions. Also contact me for support. I would be happy to s
end out 10000 emails in your behalf Absolutely free,to get your business off and running.
mailto:moneywizards@juno.com
You may also call 1888-573-5132 and leave your number.
Thank you!
Bert :0)
My distributor identification No. is 56126-892601
P.S. Every small contribution to save our environment will be a major contribution for our children
. Please recycle!!
To may trees,rainforest are being cleared each day.:0( That is why I choose to advertise electron
ically. :0}>
Also if you are Interested in learning more about electronic advertising visit http://www.moneywiz
ards.com
=========================================================================
From: Dave Stagner <dstagner@icarus.net>
Subject: Re: Scanning images (was Camille Power Supply)
Date: Thu, 5 Nov 1998 21:23:17 -0600 (EST)
Source: Sound Digest Archive v01.n482
On Fri, 6 Nov 1998, Robert Jorgensen wrote:
> I had a look at the images and while it is excellent to have them up there
> can I make a few suggestions for Grover and anyone else who scans images.
>
> Most scanning software will allow you to scan color or line-art. In this
> and in similar cases where we are dealing with black and white images (no
> greyscale) it is much to be preferred to scan in 2 color. Also pay
> attention not to scan in too high a resolution. 75 dpi is fine for screens
> and 300 usually more than enough even for printing. After scanning save in
> 2 color gif.
Good advice, but i've found it better to save a 16 color greyscale GIFs.
Line art actually comes out more legible with a touch of grey (something i
learned from my job, not from the Grateful Dead). You can still get a
schematic down below 30k easily.
> Use jpg when you have color pictures. Jpg's supports 16 million colors,
> which is great (much better than gif's 256 max) and when you have scanned
> the picture and want to save it make sure that you set a compression
> setting of about 15. Otherwise you end up with huge files. The loss in
> resolution is really not great and in contrast to audio I'm all for the
> great savings in space.
Some of the better graphics programs will let you play with the
compression ratios for JPGs. It's worth experimenting if you're really
concerned with size and quality.
> Just to give an indication I could reduce the size of the Camille images to
> somewhere between 18 and 22kb a piece instead of the 160 - 170 which are on
> the bottlehead site. I'm quite willing to send the to (I forget at the
> moment who is webmastering the site), but they would be nicer if they were
> rescanned in 2 colors at a lower resolution.
>
> Just a few hints. A nice package to use is Paintshop Pro.
Paint Shop Pro is excellent, the best scanning and graphics tool for
non-professionals that i've seen. But i don't have a copy right now... my
demo license ran out and i haven't bought it yet. I tried resizing the
images with Microsoft Image Composer, but it freaked out in my mere 64M
RAM and 128M swap on Windows NT. :( Damn incompetent crap. I'd rather
just get nice copies of the images and scan them myself.
- -dave
Practice beautiful randomness and act kind of senseless.
<dstagner@icarus.net>
=========================================================================
From: Robert Jorgensen <robert.jorgensen@advalvas.be>
Subject: Scanning images (was Camille Power Supply)
Date: Fri, 06 Nov 1998 00:59:11 +0100
Source: Sound Digest Archive v01.n482
At 08:09 05/11/98 -0600, you wrote:
>
>>Some copies of the schematic (Grover Gardner's scans of the fax) are
>>already up at http://www.bottlehead.com/valve/camilleps.shtml
>>
>>If the good Doctor would be so kind as to send me the originals or clean
>>photocopies, i'll work on getting cleaner scans.
>>
>>-dave
>
>
>Thanks Dave and Grover for posting what is on the site now. That is what I
>did to my amp after returning from this year's VSAC. Made the old (damper
>diode) supply sound a little slow and a little dirty by comparison.
>
>I'm really looking forward, however, to the "high-tech shunt regulated"
>portion of the new design. Please let us know when it is posted. - Pat
>
>
I had a look at the images and while it is excellent to have them up there
can I make a few suggestions for Grover and anyone else who scans images.
Most scanning software will allow you to scan color or line-art. In this
and in similar cases where we are dealing with black and white images (no
greyscale) it is much to be preferred to scan in 2 color. Also pay
attention not to scan in too high a resolution. 75 dpi is fine for screens
and 300 usually more than enough even for printing. After scanning save in
2 color gif.
Use jpg when you have color pictures. Jpg's supports 16 million colors,
which is great (much better than gif's 256 max) and when you have scanned
the picture and want to save it make sure that you set a compression
setting of about 15. Otherwise you end up with huge files. The loss in
resolution is really not great and in contrast to audio I'm all for the
great savings in space.
Notice that the jpg format is inferior to 2 color gif when we are talking
drawings etc. You usually end up have hundreds of shades of white and not
quite black which is a real pain. If youscan at the right resolution you
also avoid some of the jagged edges which often appear when resizing an
image to a resonable size.
Just to give an indication I could reduce the size of the Camille images to
somewhere between 18 and 22kb a piece instead of the 160 - 170 which are on
the bottlehead site. I'm quite willing to send the to (I forget at the
moment who is webmastering the site), but they would be nicer if they were
rescanned in 2 colors at a lower resolution.
Just a few hints. A nice package to use is Paintshop Pro.
Greetings from Brussels
Robert
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: Scanning images (was Camille Power Supply)
Date: Fri, 06 Nov 1998 02:07:46 GMT
Source: Sound Digest Archive v01.n482
On Fri, 06 Nov 1998 00:59:11 +0100, Robert Jorgensen
<robert.jorgensen@advalvas.be> wrote:
>Just to give an indication I could reduce the size of the Camille images to
>somewhere between 18 and 22kb a piece instead of the 160 - 170 which are on
>the bottlehead site.
You mean so that, like, the entire image could be viewed at once? <G>
It is frustrating to deal with an image on screen that has to be
scrolled, even on a 17" monitor at 1280x1024.
Fortunately I just saved the images, viewed them offline w/Photoshop,
and was able to print onto 8.5"x11" standard paper. As presented on
the web page, the images are too unwieldy to view.
- --dnb
=========================================================================
From: Marc Elmlund <marc@wineasy.se>
Subject: Re: Scanning images (was Camille Power Supply)
Date: Fri, 6 Nov 1998 02:35:07 +0100
Source: Sound Digest Archive v01.n482
At 00.59 +0100 98-11-06, Robert Jorgensen wrote:
>I had a look at the images and while it is excellent to have them up there
>can I make a few suggestions for Grover and anyone else who scans images.
<SNIP>
>Just a few hints. A nice package to use is Paintshop Pro.
And good hints too. The best app for images is of course PhotoShop but
since it costs a lot of money and you might not need all its features,
Paintshop Pro is a good alternative and for all you Mac users out there
ColorIt (http://www.microfrontier.com/index.html) is a good alternative.
Also if you wanna learn more about scanning, check out
http://www.scantips.com/
Marc Elmlund
millimeter media
Stockholm, Sweden
marc@millimetermedia.com
=========================================================================
From: Hartmut Quaschik <Hartmut.Quaschik@bku.db.de>
Subject: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: 03 Dec 1998 11:50:17 +0100
Source: Sound Digest Archive v01.n516
Lynn,
thanks for your detailed opinion about the aerogel sound.
now, another new cone material, the carbon paper composites, like Scanspeak'18 inch
woofer-midranges, what are your experiences with them ?
thanks, and regards,
Hartmut from Munich, now in Frankfurt
=========================================================================
From: "Lynn T. Olson" <lynno@teleport.com>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Sat, 5 Dec 1998 03:31:47 -0800
Source: Sound Digest Archive v01.n520
>Lynn,
>
>thanks for your detailed opinion about the aerogel sound.
>
>now, another new cone material, the carbon paper composites, like
>Scanspeak'18 inch
>woofer-midranges, what are your experiences with them ?
>
>thanks, and regards,
>Hartmut from Munich, now in Frankfurt
Well, you must keep in mind in that this posting comes from the World
Headquarters of the International
Jensen/Lundahl/MagneQuest/Tango/Tamura/Electra-Print Magnetic Coupling
Conspiracy. You have been warned!
That out of the way, I like carbon fiber, especially the new Scan-Speak
18cm drivers (not 18 inches!), but they are hellishly difficult to work
with. One of the things that isn't so nice about carbon-fiber composites is
a typical double-peak structure around 3.5 to 4kHz, with the peaks about
200 to 500Hz apart. This isn't obvious on the freq resp curves, but look
closely at the back of the 3D waterfall plots, where smoothing is
impossible. In the Scan drivers, the dual peaks are well damped, maybe as
low as 2dB, but still there. In other brands of carbon-fiber drivers, the
dual-peak structure can be as big as 10dB, no small thing at all.
Current fashion in both ultra-fi and mainstream circles is for minimalist
crossovers. This makes it difficult to address a complex upper-midband
resonant structure, and the high-end speakers I've heard that use these
drivers instead conceal the peaks by crossing low and exhibiting the system
with rolled-off cables and electronics. This helps. It also helps that most
reviewers have never auditioned drivers "barefoot" without any crossover at
all.
This is a disheartening experience, and has the drawback of teaching the
listener the characteristic sound of Kevlar, carbon-fiber, polypropylene,
etc. Note that paper can sound like anything due to the huge number of
variables that go into paper-making. If a Japanese mfg. says that
sprucewood pulp sounds different, I take that seriously. It is very
difficult to get away from the fundamental sonic character of cone
materials ... at best, even the trickiest crossover merely conceals the
truth of the matter.
Crossover design tends to fall into two schools: the "necessary-evil"
minimalists, who keep the parts count as low as possible, and the folks who
use them as equalizers as well as crossovers. At one time, I was thought of
as a minimalist, but that was a while ago. Nowadays my type of design is
quite out of fashion, although the Ariel is lots simpler than other systems
I've done. There are horns out there with sophisticated crossovers, and the
eXemplar is probably the best example I can think of at the moment. The
Altec drivers are *not* easy to equalize, and I am deeply impressed at the
sheer dedication it must have taken to design this speaker.
All of this ultimately comes down to the "tolerable coloration" threshold
of the individual listener. This is highly variable, even in reviewers.
Reading reviews of speakers with plainly audible (and measurable) cone
colorations leads me to believe that high-end magazine reviewers aren't too
bothered by the sound of Kevlar or carbon-fiber breakup, and tend to
attribute it to cables, amps, anything but the driver. Since I am very
sensitive to coloration in the 1 to 5kHz region, but accept a fair amount
of coloration elsewhere, this puts me out of step with current design
trends.
The Scan-Speak 18cm carbon-fiber drivers have exceptionally low IM
distortion due to the cone material and the magnetic field design, and this
results in the clarity in the midbass and midband they are known for. To
beat them at this game, you have to go to big prosound drivers, and the big
boys start to wiggle up and down about an octave or more lower than the
Scan-Speaks.
As mentioned in my book, speaker design is a series of not-so-pleasant
tradeoffs. Rigid cones have lower IM distortion (more clarity and "speed")
but also have not so nice breakup regions that can very level-dependent. By
contrast, softer cones are much smoother and have a gentler entry into the
breakup region, but also have more IM distortion, thus are more vague
sounding and have less "snap" to the sound.
One way to cheat is to use multiple drivers (it seem to work better in
speakers than amps for some reason) and have lots of little cones. This is
the principle behind the Superwhamodynes, but there are tradeoffs there as
well, mostly in polar patterns that get real tricky around the crossover.
This makes measurements tough, since with a complex polar pattern
correlation between what you hear and what you measure goes down ... fast.
I'm sure Dan could bore all of us with tales of optimizing the Whamos ...
but he's not alone here. The most tedious and agonizing part of speaker
design is the optimization, knowing all the while that you hear things
different than other people, and they will easily hear things on first
audition that you couldn't here in five months of hassle with a spectrum
analyser and a pile of test discs.
I guess I still haven't answered your question about the Scan carbon-fiber
drivers. I don't have the courage to attempt a dual-notch crossover to
fully equalize the drivers, and I know that using a single notch creates a
major zero in the response if there are two closely-spaced peaks. This
creates a speaker with extreme sensitivity to listening location and an odd
fatiguing sound that won't appear in most measurements since the tweeter
will "fill in" the full nature and scope of the response zero. So in
practice, gentle response shaping instead of full notch equalization
probably works best.
Mike McCall, designer of the "Eire" speakers, probably has done the best
job of taming the Scan-Speak carbon-fiber driver while keeping the
characteristic speed and clarity. I gather that he had to cross the driver
*very* low, maybe around 1.5kHz to 2kHz, and do a lot of response shaping
in the rolloff region to get it to blend with the tweeter. Even with
LEAP/LMS, the fine-tuning took him a full year, and I can believe it.
(Mike's a real nice guy, so please don't bug him with requests for free
copies of the Eire design ... he deserves compensation for the work he's
done creating one of the best Scan-driver speakers around.)
Working with drivers that are great but have problems too is a lot of work
... I still vividly remember the days and months of struggling with the KEF
B110, one of my least favorite drivers of all time. After that, a
linear-phase speaker built around the Audax 6.5" was lots easier.
Lynn Olson
Editor, Valve & Tube News
E-mail: lynno@teleport.com
Ariel Speaker Page: http://www.teleport.com/~lynno/Ariel.htm
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Sat, 05 Dec 1998 14:37:03 +0100
Source: Sound Digest Archive v01.n520
"Lynn T. Olson" wrote:
> Crossover design tends to fall into two schools: the "necessary-evil"
> minimalists, who keep the parts count as low as possible, and the folks who
> use them as equalizers as well as crossovers.
(snip)
> I guess I still haven't answered your question about the Scan carbon-fiber
> drivers. I don't have the courage to attempt a dual-notch crossover to
> fully equalize the drivers, and I know that using a single notch creates a
> major zero in the response if there are two closely-spaced peaks.
Go digital, I'd suggest. Active DSP-based crossover/equalizers like the BSS
Omnidrive FDS388 or FDS355 allow multiple and very flexible, steep notch
filters (smallest is 0.1 octave, if I recall correctly). And after one month
of listening, I have to admit that op-amp technology isn't as bad as it used
to be...
Christian
=========================================================================
From: bill gardner <wg44929@navix.net>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Sat, 05 Dec 1998 09:41:37 -0600
Source: Sound Digest Archive v01.n521
At 03:31 AM 12/5/98 -0800, Lynn T. Olson wrote:
Even with
>LEAP/LMS, the fine-tuning took him a full year, and I can believe it.
>(Mike's a real nice guy, so please don't bug him with requests for free
>copies of the Eire design ... he deserves compensation for the work he's
>done creating one of the best Scan-driver speakers around.)
>
Gee whiz you mean some of these patch wearing outlaw j-net whizzer riders
are CHEAP....... this can't be .... we all know world class audio
reproduction can be realized for under 99.00!Scottie switch on the atomic
ion double throw down inverted 6L6 OTL parfeed flame shield . Captain Blue
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Sat, 05 Dec 1998 11:59:11 -0800
Source: Sound Digest Archive v01.n521
Lynn T. Olson wrote:
> ...major snippage...
> ... It also helps that most
> reviewers have never auditioned drivers "barefoot" without any crossover at
> all.
>
> This is a disheartening experience, and has the drawback of teaching the
> listener the characteristic sound of Kevlar, carbon-fiber, polypropylene,
> etc. Note that paper can sound like anything due to the huge number of
> variables that go into paper-making. If a Japanese mfg. says that
> sprucewood pulp sounds different, I take that seriously. It is very
> difficult to get away from the fundamental sonic character of cone
> materials ... at best, even the trickiest crossover merely conceals the
> truth of the matter.
> ...I also snipped thje rest of this great post (thanks, Lynn!)...
Just a bit to validate this. Back in the early days of the SEX kit
speaker (two 5" drivers on a 2-ft square baffle), I made a pair with
the Pioneer fullrange to compare with Dan's aluminum cone jobs. The
contrast was amazingly vivid. His sounded like tinfoil (the heavy-duty
barbeque kind); mine sounded like cardboard (the back-of-the-notepad
kind) or perhaps thickish construction paper. The ear's ability to
classify sound is simply amazing; there was no question about these
sounds, you could immediately identify them.
- -Paul Joppa
=========================================================================
From: Mike McCall <shamrock@voyager.viser.net>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Sat, 05 Dec 1998 13:16:33 -0800
Source: Sound Digest Archive v01.n521
At 03:31 AM 12/5/98 -0800, Lynn T. Olson wrote:
>Mike McCall, designer of the "Eire" speakers, probably has done the best
>job of taming the Scan-Speak carbon-fiber driver while keeping the
>characteristic speed and clarity. I gather that he had to cross the driver
>*very* low, maybe around 1.5kHz to 2kHz, and do a lot of response shaping
>in the rolloff region to get it to blend with the tweeter. Even with
>LEAP/LMS, the fine-tuning took him a full year, and I can believe it.
>(Mike's a real nice guy, so please don't bug him with requests for free
>copies of the Eire design ... he deserves compensation for the work he's
>done creating one of the best Scan-driver speakers around.)
Well, the Eire did take me about a year to get to a point where I was
satisfied with it, but I'm a picky bastard anyway. The x-over point turned
out to be about 2.1k, but that's not the whole story. The tweeter was the
easy part. The woofer turned out to be a real learning experience.
Lynn's right about the double bump toward the top. Not only are these a
PITA, but the phase gyrations caused by them proved to be a challenge as
well. Many designers simply cop-out and flip the polarity of the tweeter to
get a blend at x-over. I must admit, in this case it makes things allot
easier. However, I'm a wee bit retentive about such practices and view it
as a complete cop-out. A few folks who use this woofer stuck it out and
kept the drivers in phase. These guys get major points with me based on
that fact alone, irregardless of the final results. The effort alone
deserves some credit in this case.
The Eire uses no notch filters whatsoever. There is a C/R network in the
high-pass section that's used to EQ the top of the tweeter response, but
it's broadband and low Q. I don't consider this a notch filter.
The low-pass section uses a third-order topology to achieve something that
resembles a second-order roll-off that transitions to a fourth-order
roll-off. The knee isn't really a knee in this case, it looks more like a
ski slope. This driver starts its gyrations around 1.8k, and the slope
starts around 1.5k. Above about 1.8k the driver begins its transition to a
steeper slope. This goofy looking amplitude response and the changes in
slopes are used to not only manipulate the amplitude, but the phase
rotation and driver interaction. This way we're able to achieve a flat
response through the entire system AND keep the drivers in phase. Further,
we were able to present a very benign load to the amplifier. When we say
it's an 8 Ohm load, we mean it. One reviewer found this out the hard way.
One client of ours is running the Eire on 8 Watts of single-ended
horsepower and is quite pleased with the results. This ain't textbook stuff
and you won't learn it from a cookbook!
Because of this aggressive and anal retentive approach, the Eire won't
start coming apart as you start shoving the coal to it. The x-over holds
together at any volume level. Some x-overs do their job at lower volumes
but start loosing their cookies as the volume goes up. Any problems that
are only masked at lower volumes often rear their ugly heads as the volume
increases. Stiff cones and minimal x-overs are notorious for this.
Regards,
Mike McCall
Shamrock Audio
(503) 873-3755
http://www.shamrockaudio.com
shamrock@viser.net
=========================================================================
From: Tom Ronan <tronan@orion.it.luc.edu>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Sat, 05 Dec 1998 14:59:26 -0600
Source: Sound Digest Archive v01.n521
Lynn wrote (and was subsequently snipped down to):
>> This is a disheartening experience, and has the drawback of teaching the
>> listener the characteristic sound of Kevlar, carbon-fiber, polypropylene,
>> etc. Note that paper can sound like anything due to the huge number of
>> variables that go into paper-making.
and then Paul Joppa wrote:
>contrast was amazingly vivid. His sounded like tinfoil (the heavy-duty
>barbeque kind); mine sounded like cardboard (the back-of-the-notepad
>kind) or perhaps thickish construction paper. The ear's ability to
>classify sound is simply amazing;
I've noticed this over time listening to Lowther speakers. My ears can get
used to different sounds on different systems. (like the fact that the
Diatones sound different than the Lowthers in terms of the tone of the
material - both with no crossovers) What I can't seem to get used to
anymore is two material sounds in the same system. When the highs sound
like they are coming from a metal 'thingy' and the mids from a paper
'thingy' things just sound wrong. Though I love horns and horn sound done
well, even with BigAss (TM) horns going down to 300Hz, there is still a
discontinuity in 'material sound' in male voices and even in low signing
women. Whatever the Lowthers flaws, all of the music comes from the same
material and sounds much more coherant to my ears.
One thing I have found is that below male vocals, the tone is much less
important. There is a character imparted to the bass that matters (like a
ported box sounds stinky, but a sealed box sounds better) when matched to
the Lowthers, but amazingly enough, below 100 Hz or 150 Hz, rather than
tone you are just adding 'presence' or weight to the music. Except for
that 'character' mentioned above, there's suprisingly little that seems
important other than for it to be there. (I still have yet to hear a big
bass horn, so I'll hold my judgments as to that style until I hear it.)
Tom
- ----------------------------------------
Tom Ronan 1045 W. Montana
773.528.0882 Chicago, IL 60614
Lowther America - Chicago Representative
=========================================================================
From: "Norman Tracy" <ntracy@galstar.com>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Wed, 9 Dec 1998 00:42:25 -0600
Source: Sound Digest Archive v01.n530
Lynn T. Olson wrote:
> Well, you must keep in mind in that this posting comes from the World
> Headquarters of the International
> Jensen/Lundahl/MagneQuest/Tango/Tamura/Electra-Print Magnetic Coupling
> Conspiracy. You have been warned!
GOOD GOD MAN YOU'VE BLOWN YOUR COVER! What ever happened to plausible
deniability?!? Our fearless leader, Mr. Henry, has ordered you to take your
pill now. If the CIA, FBI, or worse yet lawyers from Ken Star burst in
before you can get to the pill just bite one of those mercury rectifiers on
your amp placed there for just such a grim purpose. Our operatives will
come in after the fact to make it appear you expired from grabbing a hot B+
line while trying to do the right thing getting that crap iron out of your
amps repenting of your evil ways and installing all Tango/Tamura.
Oh, but before you go could you answer just one more question? You wrote:
> That out of the way, I like carbon fiber, especially the new Scan-Speak
> 18cm drivers (not 18 inches!), but they are hellishly difficult to work
> with. One of the things that isn't so nice about carbon-fiber composites
is
> a typical double-peak structure around 3.5 to 4kHz, with the peaks about
> 200 to 500Hz apart. This isn't obvious on the freq resp curves, but look
> closely at the back of the 3D waterfall plots, where smoothing is
> impossible. In the Scan drivers, the dual peaks are well damped, maybe as
> low as 2dB, but still there. In other brands of carbon-fiber drivers, the
> dual-peak structure can be as big as 10dB, no small thing at all.
And you and Mike McCall have shared quite a bit more great info on the
taming of such beastes with notches in their passive crossovers.
What about an active approach? Specifically I have in mind those of us with
more electronics experience and talent over speaker design. Also often
several channels of power amps laying about. Add the Marchand Electronics
(updated site at: http://www.marchandelec.com/) XM26 24 dB/octave tube
crossover (http://www.marchandelec.com/xm26.htm) and we are ready for
bi-amped bliss. So really the simple version of my question becomes:
With 24 dB/octave active crossovers upstream set at say 2kHz, will the
'typical double-peak structure around 3.5 to 4kHz' of drivers such as the
Scan-Speak be excited? Would notch filtering still be required? I want to
direct drive the drivers right off the tube amps.
happy holidays
Norman Tracy
=========================================================================
From: "Lynn T. Olson" <lynno@teleport.com>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Wed, 9 Dec 1998 04:31:14 -0800
Source: Sound Digest Archive v01.n530
>What about an active approach? Specifically I have in mind those of us with
>more electronics experience and talent over speaker design. Also often
>several channels of power amps laying about. Add the Marchand Electronics
>(updated site at: http://www.marchandelec.com/) XM26 24 dB/octave tube
>crossover (http://www.marchandelec.com/xm26.htm) and we are ready for
>bi-amped bliss. So really the simple version of my question becomes:
>
>With 24 dB/octave active crossovers upstream set at say 2kHz, will the
>'typical double-peak structure around 3.5 to 4kHz' of drivers such as the
>Scan-Speak be excited? Would notch filtering still be required? I want to
>direct drive the drivers right off the tube amps.
>
>happy holidays
>
>Norman Tracy
Well, cover blown, I proceed forward anyway.
You bring up an area of controversy between the Brit and the US schools of
design. Back in the Fifties, D.E.L. Shorter of the BBC discovered the
phenomenon of "buried resonance", where resonances 6 to 20dB below the main
curve were still quite audible despite being essentially invisible on the
standard swept freq graphs. He went on to invent a chopped-sinewave
technique that triggered a scope when the chopped-sinewave was cut off ...
as you swept thru the trouble region, you'd see narrowband "tails" on the
chopped-off segment. These days, you simply use MLSSA or the equivalent and
look at the waterfall spectra.
The Americans, especially the West Coast school, never put much stock in
this source of coloration and placed their trust in 1/3 octave techniques,
which not coincidentally favored West Coast-school speakers, while the BBC
technique made them look pretty bad.
This persists in modern studio monitors, which are "fixed in the mix" via
DSP techniques, and back in the Seventies, by extensive 1/3 octave
smoothing. Measures flat = sounds flat, basically. I am out of step with
this school.
I don't put full weight on the overall system curve, paying more attention
to carefully controlled rolloff regions, which play a major role in the
phase relations between the drivers in the crossover region. This
inter-driver phase angle essentially controls the polar pattern at
crossover.
As you may imagine, a little bump about 20dB down certainly won't appear as
much on the overall system curve, but it *will* affect the inter-driver
phase angle, resulting in a narrow-band jump in polar pattern. Some folks
don't mind this kind of thing, but I do, and I consider it a degradation of
image quality and a source of listening fatigue.
So I like the "belt-and-suspenders" approach of resonance correction *and*
devising an electrical network that results in the desired acoustic
response rolloff, at least for 20 to 30dB down if at all possible. My
subjective test for inter-driver phase is to turn the speaker on its side,
listen to pink-noise, and assess if a virtual source is located between the
two physical drivers with no instability ... and from a listening distance
of 1 to 2 feet. Few speakers pass this test, giving a disjointed two-driver
or three-driver impression instead.
So the secret to non-obtrusive crossovers is choosing cone materials that
have similar IM signatures, avoidance of standing waves in cone materials
or enclosure exteriors, and careful control of inter-driver phase angle
over a broad frequency range. Do that and the system will be coherent
sounding.
The indirect aswer to the question above is that active crossovers may
require just as many reactive components as the passive equivalent if
equivalent correction accuracy is desired, so the op-amp or buffer count
may get pretty high. Thus DSP raises its head, with the fun challenge of
A/D conversion added to what started as a simple crossover problem. I would
caution DSP advocates to not over-equalize, and make sure the goal is
subjective flatness with a repeatable source.
Lynn Olson
Editor, Valve & Tube News
E-mail: lynno@teleport.com
Ariel Speaker Page: http://www.teleport.com/~lynno/Ariel.htm
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Wed, 09 Dec 1998 10:16:44 +0100
Source: Sound Digest Archive v01.n530
Norman
IMHO it takes more than just active x-over -- this doesn't solve the peaks.
What you'd need is a DSP-based active x-over that lets you EQ the peaks in the
digital domain. (like the BSS Omnidrive...)
Christian
Norman Tracy wrote:
> What about an active approach? Specifically I have in mind those of us with
> more electronics experience and talent over speaker design. Also often
> several channels of power amps laying about. Add the Marchand Electronics
> (updated site at: http://www.marchandelec.com/) XM26 24 dB/octave tube
> crossover (http://www.marchandelec.com/xm26.htm) and we are ready for
> bi-amped bliss. So really the simple version of my question becomes:
>
> With 24 dB/octave active crossovers upstream set at say 2kHz, will the
> 'typical double-peak structure around 3.5 to 4kHz' of drivers such as the
> Scan-Speak be excited? Would notch filtering still be required? I want to
> direct drive the drivers right off the tube amps.
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: Scanspeak Carbon-paper cones, was: lurker & aerogel
Date: Wed, 09 Dec 1998 12:26:34 +0100
Source: Sound Digest Archive v01.n530
About damping of resonances:
Most resonances cannot be damped by the amplifier (impedance) since at
resonance no relation between applied voltage and cone excursion exsist.
Therefor damping should come from the unit itself, if neccessary.
One trick:
Simple tweeter filters only use a series-capacitor. Since below the cut
off, the impedance of the cap is high, no damping appears below the cut-off
(resonance frequency). A simple resistor parallel to the tweeter of say 22
ohm adds damping.
Guido
At 00:42 9-12-98 -0600, Norman Tracy wrote:
>
>Lynn T. Olson wrote:
>> Well, you must keep in mind in that this posting comes from the World
>> Headquarters of the International
>> Jensen/Lundahl/MagneQuest/Tango/Tamura/Electra-Print Magnetic Coupling
>> Conspiracy. You have been warned!
>
>GOOD GOD MAN YOU'VE BLOWN YOUR COVER! What ever happened to plausible
>deniability?!? Our fearless leader, Mr. Henry, has ordered you to take your
>pill now. If the CIA, FBI, or worse yet lawyers from Ken Star burst in
>before you can get to the pill just bite one of those mercury rectifiers on
>your amp placed there for just such a grim purpose. Our operatives will
>come in after the fact to make it appear you expired from grabbing a hot B+
>line while trying to do the right thing getting that crap iron out of your
>amps repenting of your evil ways and installing all Tango/Tamura.
>
>Oh, but before you go could you answer just one more question? You wrote:
>
>> That out of the way, I like carbon fiber, especially the new Scan-Speak
>> 18cm drivers (not 18 inches!), but they are hellishly difficult to work
>> with. One of the things that isn't so nice about carbon-fiber composites
>is
>> a typical double-peak structure around 3.5 to 4kHz, with the peaks about
>> 200 to 500Hz apart. This isn't obvious on the freq resp curves, but look
>> closely at the back of the 3D waterfall plots, where smoothing is
>> impossible. In the Scan drivers, the dual peaks are well damped, maybe as
>> low as 2dB, but still there. In other brands of carbon-fiber drivers, the
>> dual-peak structure can be as big as 10dB, no small thing at all.
>
>And you and Mike McCall have shared quite a bit more great info on the
>taming of such beastes with notches in their passive crossovers.
>
>What about an active approach? Specifically I have in mind those of us with
>more electronics experience and talent over speaker design. Also often
>several channels of power amps laying about. Add the Marchand Electronics
>(updated site at: http://www.marchandelec.com/) XM26 24 dB/octave tube
>crossover (http://www.marchandelec.com/xm26.htm) and we are ready for
>bi-amped bliss. So really the simple version of my question becomes:
>
>With 24 dB/octave active crossovers upstream set at say 2kHz, will the
>'typical double-peak structure around 3.5 to 4kHz' of drivers such as the
>Scan-Speak be excited? Would notch filtering still be required? I want to
>direct drive the drivers right off the tube amps.
>
>happy holidays
>
>Norman Tracy
>
>
=========================================================================
From: Esther Ang Pty Ltd <rang@opera.iinet.net.au>
Subject: Scan-Speak Order for Australians
Date: Mon, 7 Sep 1998 10:30:06 +0800 (WST)
Source: Sound Digest Archive v01.n414
Paging all Australian Joes.
I am in the middle of putting an order in with Scan-Speak, direct from
Denmark. If anyone in Australia would like to join the order, could you
please email me ASAP? Yep, Lynn, I'm getting pretty serious about these
Ariels... the cabinets are 50% finished, and I've got nearly all the parts
except the tweeters...
Rob.
=========================================================================
From: JEAN-PHILIP_GARIGON@HP-Germany-om7.om.hp.com
Subject: schematic 2 way active ?
Date: Fri, 31 Oct 97 10:43:24 +0100
Source: Sound Digest Archive v01.n096
Hello.
Has somebody a schematic for a 2way active system ?
( on net or somewhere)
Thanks
JP
=========================================================================
From: Rick Francis <rfranci@uoft03.UTOLEDO.EDU>
Subject: Schematic for Scott 222?
Date: Tue, 18 Nov 1997 08:59:23 -0500 (EST)
Source: Sound Digest Archive v01.n113
Having still not learned my lesson that building from scratch is more fun
than dinking on old equipment, I picked up a Scott 222 last weekend with
a blown power transformer. I hogged in a slightly bigger one I had (I
need an air scoop for the hood now), and it looks like it will work. I
wonder what the original B+ was on this pup... 320? I can hit that with
choke input, and current is not a problem, so may try reducing cathode
resistor...
But the heater supply for the preamp section is confusing, and makes my
brain hurt. Does anyone have a schematic? I'm happy to swap schematics.
Rick Francis, rfranci@uoft03.utoledo.edu
=========================================================================
From: "Robert Ang" <rang@opera.iinet.net.au>
Subject: Schematic for SE 845 Power Amp
Date: Sun, 19 Jul 1998 00:33:26 +0800
Source: Sound Digest Archive v01.n348
Hello, all.
I have finally made good with my promise of publishing the schematic for my
Charissa 845 power amp. I did it in a hurry, so there may be a few errors
on it. For those much more experienced than me, I would appreciate you
looking at it and seeing if there are any glaringly obvious mistakes or
other ways to improve the circuit. For those less experienced, you're most
welcome to email me and ask me questions.
Thank you especially to Lynn Olson, who has been a great help in audio
design, and who also provided me with the symbol libraries used in this
schematic.
Oh - the url is http://opera.iinet.net.au/~rang/
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: Schematic for SE 845 Power Amp
Date: Mon, 20 Jul 1998 01:49:30 PDT
Source: Sound Digest Archive v01.n349
Hi Robert,
>I have finally made good with my promise of publishing the schematic
>for my Charissa 845 power amp.
Hey, cool Dude. ThanX for sharing with us.
Take care.
Later Thorsten
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: Jeremy Epstein <70664.154@compuserve.com>
Subject: Re: Schematic or info WTD: Operadio 1180-B
Date: Wed, 10 Sep 1997 08:56:00 -0400
Source: Sound Digest Archive v01.n018
- --- Forwarded Message ---
Date: 09-Sep-97 18:19 EDT
From: INTERNET:tubeguy@elnet.com
Subj: Re: Schematic or info WTD: Operadio 1180-B
Sender: TubeGuy@elnet.com
Received: from shell0.elnet.com (shell0.elnet.com [206.148.64.13])
by dub-img-10.compuserve.com (8.8.6/8.8.6/2.5) with ESMTP id SAA22883
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Reply-To: <tubeguy@elnet.com>
From: "TubeGuy" <TubeGuy@elnet.com>
To: <70664.154@compuserve.com>
Subject: Re: Schematic or info WTD: Operadio 1180-B
Date: Tue, 9 Sep 1997 17:17:40 -0500
X-MSMail-Priority: Normal
X-Priority: 3
X-Mailer: Microsoft Internet Mail 4.70.1161
Jeremy Epstein <70664.154@compuserve.com> wrote in article
<873811688.8115@dejanews.com>...
> I have a pair of these '40's-era monoblocks. If anyone has information on
> them or on the Operadio company I would much appreciate it!
>
> They are giant, 1 x 6SN7, 4 x 6L6, 2 x 5Z3, 1 x 80 power amps. I have one
> working and one not - and I want two working instead!
>
> Thanks for any help,
>
I will check the archives at DuKane Corp (formerly Operadio) and see if I
can dig up anything on them. In the meantime, since you have one working
you could set them up side by side on your workbench, hook up loads and
input, and turn them both on and compare the DC volts and/or signal path.
I'll get back to you via email after my search.
Good Luck.
TubeGuy
=========================================================================
From: cjg2@concentric.net
Subject: Schematic plea--never mind--got it!
Date: Tue, 3 Nov 1998 00:53:42 -0500
Source: Sound Digest Archive v01.n478
WWW never ceased to amaze--anyone who need a SCA-schematic, point it to
http://pw2.netcom.com/~wa2ise/index.html
=========================================================================
From: Tommy Robinson <tommy_robinson@yahoo.com>
Subject: Schematics for Luxman CL35MKII & MB3045
Date: Thu, 22 Oct 1998 07:06:46 -0700 (PDT)
Source: Sound Digest Archive v01.n464
Does anyone know where I can get some schematics and copies of manuals
for these amps and preamp???? I'm also looking for info on mods to
replace the unavailable 6240G and 8045 tubes in the amps.
I am going post this to rec.audio.tubes, highend, and marketplace, also.
Thanks,
Tommy
_________________________________________________________
DO YOU YAHOO!?
Get your free @yahoo.com address at http://mail.yahoo.com
=========================================================================
From: Thomas Danley <tom@ppci.com>
Subject: Re: schematics for Svetlana SV572 833c
Date: Mon, 24 Nov 1997 21:27:16 -0600
Source: Sound Digest Archive v01.n119
Grego Sanguinetti wrote:
>
> On Sat, 22 Nov 1997, Hugh R. Dean wrote:
>
> > Have you looked at the curves on the Svetlana 833? A very good tube for
> > SE, I thought.
>
> Hey Mate,
>
> I, and a few other local looneys, have fired up 833's in SE hifi mode.
> The sound is very good, great, but...so far none of us have been prepared
> to deal with the environmental needs of this tube.
> 1. size
> 2. socketing
> 3. size
> 4. heat
> 5. 100w per tube of filament supply (see 3, 4)
> 6. size (have I mentioned heat?)
>
Hi All
The 833 is a nice tube and has an advantage over a 304th in that it is
current production. A pair with 800v plate supply, 650 ohms p/p can put
out about 500 watts (AB1, my next tube project). I am sort of puzzled
with the popularity of the single ended aproach though, for a given
power the linearity isn't nessescarily better, there is no common mode
rejection of power supply hum or even harmonics, the output transformers
are more difficult to design due to the (un-ballenced) DC current. The
only obvious advantage that I can think of is 1 tube vs 2. Is it
euphonic distortion? or is there an actual technical improvement in some
aspect of performance. I have designed and built a number of fairly
large (75-400 watts) amplifiers, but they have all been push pull, If
someone knows the technical answer, I'm keen to find out.
I have a 2kw CML industrial tube amplifier for sale if anyone is
interested in a very heavy tube novelty (uses 12, 4cx150's).
Thomas Danley
Intersonics Technology Corp
=========================================================================
From: AirGapped@aol.com
Subject: Re: schematics for Svetlana SV572 833c
Date: Tue, 25 Nov 1997 02:05:04 -0500 (EST)
Source: Sound Digest Archive v01.n119
In a message dated 97-11-25 01:10:37 EST, you write:
<< I am sort of puzzled
with the popularity of the single ended aproach though, for a given
power the linearity isn't nessescarily better, there is no common mode
rejection of power supply hum or even harmonics, the output transformers
are more difficult to design due to the (un-ballenced) DC current. >>
Tom: One problem is the sheer size of the output transformer that you would
need for a 500 watt amplifier. If you use the rule of thumb of 10 watts per
pound of iron...then your looking at a 50 pound core of iron to get the job
done.
Mike
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: schematics for Svetlana SV572 833c
Date: Tue, 25 Nov 1997 07:54:43 +0000 (GMT)
Source: Sound Digest Archive v01.n119
Thomas,
Don't mess around with 800 V, go straight for 2,500 V....the linearity
will improve no end. Unfortunately the transformer impedance goes up as
well, but it sounds great! How does a bridge of U19s grab you?
Last time I enquired the 833C was out of production at Svetlana because
they were having trouble with the carbon anodes. I prefer the sound of
these to the anodes used in the 833A, and Penta even do a 833D which is an
"uprated" version of the 833C.
Simon
Dr Simon Busbridge
University of Brighton
Lewes Road
Moulsecoomb
Brighton BN2 4GJ
UNITED KINGDOM
Tel: 0044 (0)1273 642542
Fax: 0044 (0)1273 642327
e-mail: s.c.busbridge@bton.ac.uk
"..biology is what you do when you don't have the maths for real
science.." (sliders)
On Mon, 24 Nov 1997, Thomas Danley wrote:
> Grego Sanguinetti wrote:
> >
> > On Sat, 22 Nov 1997, Hugh R. Dean wrote:
> >
> > > Have you looked at the curves on the Svetlana 833? A very good tube for
> > > SE, I thought.
> >
> > Hey Mate,
> >
> > I, and a few other local looneys, have fired up 833's in SE hifi mode.
> > The sound is very good, great, but...so far none of us have been prepared
> > to deal with the environmental needs of this tube.
> > 1. size
> > 2. socketing
> > 3. size
> > 4. heat
> > 5. 100w per tube of filament supply (see 3, 4)
> > 6. size (have I mentioned heat?)
> >
>
> Hi All
>
> The 833 is a nice tube and has an advantage over a 304th in that it is
> current production. A pair with 800v plate supply, 650 ohms p/p can put
> out about 500 watts (AB1, my next tube project). I am sort of puzzled
> with the popularity of the single ended aproach though, for a given
> power the linearity isn't nessescarily better, there is no common mode
> rejection of power supply hum or even harmonics, the output transformers
> are more difficult to design due to the (un-ballenced) DC current. The
> only obvious advantage that I can think of is 1 tube vs 2. Is it
> euphonic distortion? or is there an actual technical improvement in some
> aspect of performance. I have designed and built a number of fairly
> large (75-400 watts) amplifiers, but they have all been push pull, If
> someone knows the technical answer, I'm keen to find out.
> I have a 2kw CML industrial tube amplifier for sale if anyone is
> interested in a very heavy tube novelty (uses 12, 4cx150's).
>
> Thomas Danley
> Intersonics Technology Corp
>
=========================================================================
From: Bob Danielak <rdaniela@ew.lmms.lmco.com>
Subject: Re: schematics for Svetlana SV572
Date: Fri, 21 Nov 1997 09:38:19 -0500
Source: Sound Digest Archive v01.n116
Paolo Del Giusto wrote:
>
> Hi people,
> I'm looking for a good schematic for the SV572 series of valve. Any suggestion?
>
> And about the power triode 3CX300A1, always from Svetlana?
>
> Thanks in advance
>
> ----------------------------------------------------------
> ----------------Paolo Del Giusto--------------------------
> ----------------------------------------------------------
> ----------paolo.delgiusto@studioidea.it-------------------
> ----------------------------------------------------------
funny you should mention it...
i just put up a new page on my web site covering an amp that uses
sv572-30 -or- sv572-3.
i call it the "convertable" in memory of my last fiat spider... ;)
have a look:
http://www.geocities.com/TimesSquare/1965/se_sv572.html
i've also built a 120W push-pull amp using the 3cx300a1:
http://www.geocities.com/TimesSquare/1965/pp3cx300.html
another amp using svetlana tubes is at :
http://www.geocities.com/TimesSquare/1965/se_sv811.html
this one uses the sv811-10, but you can also plug in the sv572-10...
i personally think that the 811-10 sounds better in this application.
the 572-10 really wants to be run at a bit higher plate dissipation.
interestingly enough, i've found that the 572-30 doesn't seem to
mind lower plate dissipation. it sounded pretty good plugged
into the sv811 amp . this was certainly not an optimal
arrangement. i biased it to about +15 to +20 at 400V and it did
ok.
but in the new "convertable" amp it really rocks!
should be able to play with it a little more over the weekend.
if there is any interest i'll give some more details on the joenet...
take care,
bob.d.
=========================================================================
From: Grover Gardner <groverg@bellatlantic.net>
Subject: Re: schematics for Svetlana SV572
Date: Fri, 21 Nov 1997 10:33:34 -0600
Source: Sound Digest Archive v01.n116
At 3:16 PM +0100 11/21/97, Paolo Del Giusto wrote:
> Hi people,
>I'm looking for a good schematic for the SV572 series of valve. Any
>suggestion?
>
>And about the power triode 3CX300A1, always from Svetlana?
>
>Thanks in advance
Why not look on the Svetlana web site? There are several very good,
well-documented projects for their SE tubes.
Grover Gardner
groverg@bellatlantic.net
=========================================================================
From: paolo.delgiusto@studioidea.it (Paolo Del Giusto)
Subject: schematics for Svetlana SV572
Date: Fri, 21 Nov 1997 15:16:01 +0100
Source: Sound Digest Archive v01.n116
Hi people,
I'm looking for a good schematic for the SV572 series of valve. Any suggestion?
And about the power triode 3CX300A1, always from Svetlana?
Thanks in advance
- ----------------------------------------------------------
- ----------------Paolo Del Giusto--------------------------
- ----------------------------------------------------------
- ----------paolo.delgiusto@studioidea.it-------------------
- ----------------------------------------------------------
=========================================================================
From: Grover Gardner <groverg@bellatlantic.net>
Subject: Re: schematics for Svetlana SV572
Date: Sat, 22 Nov 1997 12:43:06 -0600
Source: Sound Digest Archive v01.n117
At 9:54 PM +1100 11/22/97, Hugh R. Dean wrote:
>Interesting choice, the 6BM8. Obviously purpose designed for voltage
>gain/driver duties. Are there any triodes in the 20-30mA range which make
>good drivers? How about the 6CK4?
The 6AH4-G is a nice little octal triode which is a dead ringer for a 6L6
in triode config. They are dirt cheap in these parts. It sounds similar
to the low-mu half of a 6EM7. It doesn't have the ease and sweetness of a
DHT, which is why I don't use it, but one could probably work with it and
get an awfully good sound. I certainly has punch...
Grover Gardner
groverg@bellatlantic.net
=========================================================================
From: "Hugh R. Dean" <aspen@alphalink.com.au>
Subject: Re: schematics for Svetlana SV572
Date: Sat, 22 Nov 1997 21:54:29 +1100
Source: Sound Digest Archive v01.n117
Hi Bob, you wrote:
>i just put up a new page on my web site covering an amp that uses
>sv572-30 -or- sv572-3.
>
>i call it the "convertable" in memory of my last fiat spider... ;)
>
>have a look:
>
>http://www.geocities.com/TimesSquare/1965/se_sv572.html
>
>i've also built a 120W push-pull amp using the 3cx300a1:
>
>http://www.geocities.com/TimesSquare/1965/pp3cx300.html
>
>another amp using svetlana tubes is at :
>
>http://www.geocities.com/TimesSquare/1965/se_sv811.html
>
>this one uses the sv811-10, but you can also plug in the sv572-10...
>i personally think that the 811-10 sounds better in this application.
>the 572-10 really wants to be run at a bit higher plate dissipation.
>
>interestingly enough, i've found that the 572-30 doesn't seem to
>mind lower plate dissipation. it sounded pretty good plugged
>into the sv811 amp . this was certainly not an optimal
>arrangement. i biased it to about +15 to +20 at 400V and it did
>ok.
>
>but in the new "convertable" amp it really rocks!
>
>should be able to play with it a little more over the weekend.
>
>if there is any interest i'll give some more details on the joenet...
I had a gander at these designs and thought 'whew!"
The basic engineering in them is fantastic! Let me offer my thanks...
Have you looked at the curves on the Svetlana 833? A very good tube for
SE, I thought.
I contrast your presentation with the bullshit you hear from technical
neanderthals in the high end hifi stores, and realise I never want to visit
them again. Much rather build my own - to your design.
Interesting choice, the 6BM8. Obviously purpose designed for voltage
gain/driver duties. Are there any triodes in the 20-30mA range which make
good drivers? How about the 6CK4?
What do you think of sonic tuning by fiddling with different component
types, Bob?
Cheers,
Hugh R. Dean
Melbourne, Australia
=========================================================================
From: Bob Danielak <rdaniela@ew.lmms.lmco.com>
Subject: Re: schematics for Svetlana SV572
Date: Mon, 24 Nov 1997 10:53:34 -0500
Source: Sound Digest Archive v01.n118
Hugh R. Dean wrote:
>
> Hi Bob, you wrote:
>
> >i just put up a new page on my web site covering an amp that uses
> >sv572-30 -or- sv572-3.
> >
> >i call it the "convertable" in memory of my last fiat spider... ;)
> >
> >have a look:
> >
> >http://www.geocities.com/TimesSquare/1965/se_sv572.html
> >
> >i've also built a 120W push-pull amp using the 3cx300a1:
> >
> >http://www.geocities.com/TimesSquare/1965/pp3cx300.html
> >
> >another amp using svetlana tubes is at :
> >
> >http://www.geocities.com/TimesSquare/1965/se_sv811.html
> >
snip
> >
> >should be able to play with it a little more over the weekend.
> >
> >if there is any interest i'll give some more details on the joenet...
>
> I had a gander at these designs and thought 'whew!"
>
> The basic engineering in them is fantastic! Let me offer my thanks...
>
<blush>
> Have you looked at the curves on the Svetlana 833? A very good tube for
> SE, I thought.
>
actually, i have a couple. i had plans to use the 833 to take my
Class A2 stuff to the next level. starting with the sv811-10
a couple years back, i finally took the next step to the sv572-30
over the last few months (had this one on paper for about a year,
waiting for the 572-30's to become available).
i actually tried out the concept using an 812 last december.
i think i even published the schematic on joe-net...
this is when i was experimenting with cathode drive/flux balancing/etc.
> I contrast your presentation with the bullshit you hear from technical
> neanderthals in the high end hifi stores, and realise I never want to visit
> them again. Much rather build my own - to your design.
>
i know what you mean. i get several e-mails a week from my website
from guys asking what amp they should buy. i have to tell them
i don't know. i don't even go to compare, anymore.
> Interesting choice, the 6BM8. Obviously purpose designed for voltage
> gain/driver duties. Are there any triodes in the 20-30mA range which make
> good drivers? How about the 6CK4?
actually, the 6bm8 shows up most commonly in cheaper integrated amps.
you can build a complete pp amp with a single pair.
they don't sound too bad, either. i think i even like them
better than el84 ...biting down hard on my tounge ;P
there are plenty of dual triodes (med/low or high/low mu)
that'll work. i chose the 6bm8 because it is in current production
the svetlana version is really well made, and it fits in well with
the 572 asthetics...
>
> What do you think of sonic tuning by fiddling with different component
> types, Bob?
i try to keep an open mind, but generally i place a little more value
on the basic design, first. then i'll experiment with different
operating points (other than the ones that look best on paper).
then i'll start swapping parts. my usual part selection policy
is UWYG (use what you got).
i strive for simplicity in design (i get kidded at work for being
the atypical engineer). so i agree that with fewer components
to skew the signal, it is more likely to effect a change in sound
with a part swap.
i've yet to hear differences in wire, solder, crimps, chassis mat'l,
etc, but maybe someday i'll find the time to listen a little harder ;)
> Cheers,
>
> Hugh R. Dean
> Melbourne, Australia
=========================================================================
From: Grego Sanguinetti <grego@latticesemi.com>
Subject: Re: schematics for Svetlana SV572
Date: Mon, 24 Nov 1997 16:23:46 -0800 (PST)
Source: Sound Digest Archive v01.n119
On Sat, 22 Nov 1997, Hugh R. Dean wrote:
> Have you looked at the curves on the Svetlana 833? A very good tube for
> SE, I thought.
Hey Mate,
I, and a few other local looneys, have fired up 833's in SE hifi mode.
The sound is very good, great, but...so far none of us have been prepared
to deal with the environmental needs of this tube.
1. size
2. socketing
3. size
4. heat
5. 100w per tube of filament supply (see 3, 4)
6. size (have I mentioned heat?)
Even Ed never put his in a box B^)
> Interesting choice, the 6BM8. Obviously purpose designed for voltage
> gain/driver duties. Are there any triodes in the 20-30mA range which make
> good drivers? How about the 6CK4?
The 6GW8 is a another similar tube. My shop stereo is currently powered
by these. Seems like there are a fair number of drivers in the 20-30mA
range, especially if you consider triode wired pentodes. But for triodes at
least consider 5842, 8532, 6BL7, 6BX7,...although the last two want to
run a tad hotter, like 30-40mA. so many choices, can lead to analysis
paralysis.
- -grego, thinking of down-under, now that winter has set in...
"tie me wanderin' grid, Sid"
oh,oh, I feel a parody coming on....
=========================================================================
From: alan cameron <alan@thehub.com.au>
Subject: Re: schematics for Svetlana SV572
Date: Tue, 25 Nov 1997 12:35:52 +1000
Source: Sound Digest Archive v01.n120
At 16:23 -0800 24/11/97, Grego Sanguinetti is rumored to have typed:
> -grego, thinking of down-under, now that winter has set in...
> "tie me wanderin' grid, Sid"
> oh,oh, I feel a parody coming on....
Brs-Vegas is tres nice this time of year, Grego. Bring some of those
naughty amps that are distressing you so.
alan
ambivalent about CRT-disposal equipment.....
=========================================================================
From: davidbarnett@aristotle.net (David N. Barnett)
Subject: Re: schematics for Svetlana SV572
Date: Wed, 26 Nov 1997 23:06:35 GMT
Source: Sound Digest Archive v01.n120
On Thu, 27 Nov 1997 00:07:34 +1100, Barton Shepherd
<bartonw@ozemail.com.au> wrote:
>96 degrees today in Sydney and Summer doesn't start for another five days!
In five days? On Dec 1? Don't seasons in the southern hemisphere
change with the solstices and equinoxes? I thought summer down there
would start sometime around Dec. 21 or so. Please correct me if I'm
wrong.
- --dnb, 70 degrees in Little Rock, Arkansas, USA
=========================================================================
From: Barton Shepherd <bartonw@ozemail.com.au>
Subject: RE: schematics for Svetlana SV572
Date: Thu, 27 Nov 1997 00:07:34 +1100
Source: Sound Digest Archive v01.n120
>
- -grego, thinking of down-under, now that winter has set in...
>
Hi Grego,
96 degrees today in Sydney and Summer doesn't start for another five days!
Cheers,
Bart
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Schematics for the Onken W enclosure.
Date: Wed, 26 Nov 1997 19:06:42 +0100 (MET)
Source: Sound Digest Archive v01.n120
Hello,
I scanned the schematics of an improved version (double walls + sand
between) of the Onken W bass-reflex enclosure (it use 2 x ALTEC 416).
If someone want the picture (a 96k .tif file), I can send it to him.
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Schematics for the Prevost's horn
Date: Wed, 26 Nov 1997 18:48:48 +0100 (MET)
Source: Sound Digest Archive v01.n120
Hello everyone,
I have scanned for a friend 13 pictures describing the building of the
Prevost's horn, a 4 cells wood + sand horn very near of the Le Dauphin.
There also the scans of the plans (not so good...)
If someone is interested I can send him the pictures (256 koctets).
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: Hartmut Quaschik <Hartmut.Quaschik@bku.db.de>
Subject: Scheu, was.: REGA RB 300
Date: 08 Dec 1998 12:32:18 +0100
Source: Sound Digest Archive v01.n528
trondmeg%online.no @ Internet has written:
>PS I have also a brand new Morch UP4 and part for a Scheu plattenspieler that is this winters proje
ct.
>If anyone is interested I will report on this. I am planning to make a heavy sandwich-plinth for it
.
(as expected, when someone has said "Scheu", I have to add something)
Trond,
yes of course. I am using my Scheu with the Scheu steel base
(on a Cotter suspended base), and of course
I am interested in alternative plinths, as well as other motor drives.
In the current issue of German DIY loudspeaker mag "Klang & Ton" there
are different plinths discussed for the DIY Scheu, along with many pictures.
I guess, that Mr.Scheu himself has written the article, and the pics look
like as provided from Mr.Scheu, from his log of pics that clients have sent
to him after finishing their DIY Scheu.
The article is technical, as Mr Scheu is technician (engineer of construction,
he is working on constructing machines, and he is doing tt in the evenings.)
first, so it might be a bit flat for golden eared highly motivated Joelist
members. But it is interesting, nevertheless.
There is a whole series of articles, maybe 3, announced, discussing all aspects
of DIY turntable, including DIY tonarm (Mr Scheu also provides parts for unipivot
tonearms like point bearings etc.). As the mag is bimonthly, it then takes half
a year to get all information.
I intend to buy a scanner as well as installing my own homepage, so if you are
patient, someday I might install an unofficial Scheu homepage, similiar to
Werner Ogier's unofficial Mitchell homepage.
BTW, Manfred Huber (Joelist-member) is experimenting with different motor drives on his Scheu.
regards,
Hartmut
PS: see my stock Scheu, there named as Amazon-Scheu,
because in Germany and Switzerland the Scheu is known and tested in mags primarily
as very expensive Mitchell-like acrylic version (app. 5500,-DM) under the
name of Amazon (Amazon's chief Hartmut Janssen is co-founder of Audio Physic,
together with Joachim Gerhard), with SME3012II, on Werner Ogier's
wild tt page, http://www.geocities.com/Hollywood/Hills/4133/ttg.html
=========================================================================
From: darmah@goodnet.com
Subject: Schmacks Horn
Date: Wed, 1 Oct 1997 19:44:31 +0000
Source: Sound Digest Archive v01.n052
Hi Folks:
For those interested, the Schmacks Horn is a fairly large ( large
over all than most Lowther designs) exponential folded horn.
The dimensions are:
w = 96 cm
d = 46 cm
h = 65 cm
It was designed quite some time ago, late 50,s I think by one
????Schmacks.
It was populerized in the 1970,s in Germany because the plans
appeared in a popular speaker building book which itself seemed to be
uptdated just about annually.
It's designed for use with 8" drivers. The folding geometry is
actually quite crude ( this is in no way a critisism, just an
observation ). The first lengths of the horn consist more of chambers
that open into one another via openings that ( supposedly) follow
exponential law. The compression chamber as it were is in fact large.
A tapered box like structure is placed behind the speaker in the
first chamber, reducing the volume of this chamber and forming the
throat.
No major attempts at keeping the flare rate constant around corners
are made.
It does have the advantage a larger mouth area than most Lowther
designs however.
And while it doesn,t look like like much on the drawing board. many
people claim very good results from this design.
Best Regards
Marc S. Wauters
darmah@goodnet.com
Internet Paging: "http://wwp.mirabilis.com/544722"
I
IIIIIIIIIIIIIII
III III III III
IIIIIIIIIIIIIII
II II
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: Schmackshorn
Date: Thu, 2 Oct 1997 07:41:41 -0800
Source: Sound Digest Archive v01.n053
Several months ago Bodo Kalthoff told me about a book published in
Germany which has plans for all sorts of horns, including the
Schmackshorn:
"Lautsprechergehaeuse-Baubuck" by Klinger
I haven't corresponded with Bodo since then and haven't seen him on
this list lately, but at that time his email address was:
bodo@uni-paderborn.de
There's also some info on one of the horn DIY sites in Scandinavia.
Can't remember which one at the moment but I'll look up the URL if
anyone wants it.
Regards,
Ken Dangerfield
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: Schmackshorn
Date: Thu, 2 Oct 1997 15:48:33 -0800
Source: Sound Digest Archive v01.n054
Robert Jorgensen has reminded me that the site that has Schmackshorn
info is Thomas Dunker's:
http://invalid.ed.unit.no/~dunker/diy_hrn.html
There are 3 CAD drawings and some textual description supplied by
Thomas Eberhard. Very interesting indeed for fans of single driver
back loaded horns. Seems like someone was down this path a long
time ago :-))
Regards,
Ken Dangerfield
=========================================================================
From: Robert Jorgensen <robert.jorgensen@advalvas.be>
Subject: Re: Schmackshorn
Date: Fri, 03 Oct 1997 07:32:30 +0200
Source: Sound Digest Archive v01.n054
At 15:48 02/10/97 -0800, you wrote:
>Robert Jorgensen has reminded me that the site that has Schmackshorn
>info is Thomas Dunker's:
>
>http://invalid.ed.unit.no/~dunker/diy_hrn.html
>
>There are 3 CAD drawings and some textual description supplied by
>Thomas Eberhard. Very interesting indeed for fans of single driver
>back loaded horns. Seems like someone was down this path a long
>time ago :-))
>
>Regards,
>Ken Dangerfield
>
>
Hi Ken and All,
I seem to have for gotten to cc joenet. Thanks.
I got to think and if I'm not wrong Victor Meurisse's Vivace was a further
development of the Schmackshorn.
I've listened to the Side-Vivace both with PM2 and with REPS and it is in
my oppinion a considerably better and more balanced horn. Not small though.
You might want to look up www.lowther.com and have a look at some of the
pictures.
Greetings from Brussels
Robert Jorgensen
Robert.Jorgensen@advalvas.be
=========================================================================
From: Holger Stein <STEINMUSIC@compuserve.com>
Subject: Re:Schmacks Horn
Date: Fri, 3 Oct 1997 04:13:22 -0400
Source: Sound Digest Archive v01.n055
Yes, those speakers are not bad.
If somebody is interested, I have a pair he can get cheap.
But remember: They are BIG, situated in Germany and weight 50kg each.
Best regards
Holger Stein
STEIN HIFI SYSTEMS
Scharpenberg 64a
D- 45468 Mülheim
Germany
Fon ++49 208 32089
Fax ++49 208 390938
GSM ++49 172 2143196
STEINMUSIC@Compuserve.com
Worldwide distribution for Ennemoser's C37 Lack
.. and much more.
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Schottke diodes
Date: Tue, 09 Jun 1998 12:06:50 -0700
Source: Sound Digest Archive v01.n307
Hi All,
I just bought a lot of 40, 10 amp Schottke rectifiers (MBR10100) on ebay
for six bucks + four bucks shipping. A number of lots were offered in a
Dutch auction, but all did not sell, so several lots are still
available. Also offered were 16 amp units at something like 50 volts
for about the same price. The seller says he also has other units in
smaller quantities ranging in size from 1 amp to 250 amps. So, if there
is any interest, I will find out more details and pass it on. The
seller claims that Digikey sells these for $1.71 each in lots of 100, so
fifteen cents each (plus shipping) seems like a good thang.
Dan Marshall
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: Schottke diodes
Date: Wed, 10 Jun 1998 20:40:09 -0700
Source: Sound Digest Archive v01.n308
Hi,
The remaining batches have been relisted on ebay at:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?MfcISAPICommand=ViewListedItems&userid=scocchi3&include=0&s
ince=-1&sort=2
DM
Ken Dangerfield wrote:
>
> On 9 Jun 98 Daniel J. Marshall said:
>
> > The seller says he also has
> > other units in smaller quantities ranging in size from 1 amp to 250
> > amps. So, if there is any interest, I will find out more details
> > and pass it on.
>
> I would definitely be interested in the larger values that he has.
> If you can find out more info it would be appreciated.
>
> Regards,
> Ken Dangerfield
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: Re: Schottke diodes
Date: Thu, 11 Jun 1998 12:14:32 -0800
Source: Sound Digest Archive v01.n308
On 10 Jun 98 Daniel J. Marshall said:
> The remaining batches have been relisted on ebay at:
>
> http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?MfcISAPICommand=ViewListedI
> tems&userid=scocchi3&include=0&since=-1&sort=2
Thanks
Ken
=========================================================================
From: Rick Francis <rfranci@uoft03.UTOLEDO.EDU>
Subject: Schottky Diodes for 10v rectification-which, why? Which DRILL PRESS?
Date: Sat, 20 Dec 1997 01:09:08 -0500 (EST)
Source: Sound Digest Archive v01.n138
It works: by using the 107 vac primaries on a Stancor 6.3 vct tranny, a
cheap RatShack bridge rectifier, and some caps, I got the 10 volts I need
for an 845. (Eerie: first time I measure, the voltage creeps 9.96, 9.98,
10.00 and stops!) Even with a 6336's 5 amp draw as a load on the AC (no 845s
yet), voltage is over 10v. 20 amp capacity means never having to worry.
What's the advantage of getting Schottky's for this job? Digi-Key has a
numbing variety of them--any help deciding would be appreciated. If I
should build it with the cheap bridge and leave fancy for later, let me
know that too.
Anyone have recommendations for a drill press? I'm serious about getting
one. Anything wrong with a Delta?
Rick Francis, rfranci@uoft03.utoledo.edu
=========================================================================
From: Richard C Nevill <rnevill@is.dal.ca>
Subject: Re: Schottky Diodes for 10v rectification-which, why? Which DRILL PRESS?
Date: Mon, 22 Dec 1997 11:17:15 -0400 (AST)
Source: Sound Digest Archive v01.n139
On Sat, 20 Dec 1997, Rick Francis wrote:
>
>
> Anyone have recommendations for a drill press? I'm serious about getting
> one. Anything wrong with a Delta?
>
> Rick Francis, rfranci@uoft03.utoledo.edu
I received a Craftsman 8in. benchtop one for christmas last year and am
quite pleased with it. So far it's taken all the abuse I've thrown at it
without complaint. Came with a 1 yr. warranty and being a Sears product I
know I'll always be able to get it fixed.
Cheers
Richard Nevill
>
>
=========================================================================
From: "Donald J. Larson" <donaldj.larson@worldnet.att.net>
Subject: Schulmerich Amplifier - Help
Date: Sun, 2 Nov 1997 19:22:05 -0600
Source: Sound Digest Archive v01.n098
My first post to this forum. Thank you in advance for any assistance you
provide.
I am looking for information that will help me trouble shoot and repair a
Schulmerich Amplifier used on a circa 1946 Carillon. This systems consists
of a Carillon (bell tones produced by various length tuning forks), a two
channel mixer/amplifier built around 6L6's, and two identical boosters also
built with a typical 6L6 design. I have completed a complete tube
transfusion with little change to the symptoms, very little output. I
suspect the speakers are damaged after 50 years of exposure to the
elements. Visual inspection is possible but difficult. The 4 PA speakers
are installed about 180 feet from the amp, 60 ft
up the bell tower.
I have schematics for the boosters but not for the mixer/amp. If anyone
would have documents and or schematics for this it would be a great find.
Can someone tell me more about the typical speaker design for this
type/vintage of system. What resistance should I meter with 4 speakers?
Would these speakers have stepdown transformers? What voltage is typically
used for this type of system to drive the speakers? Your questions might
be better than mine so if you have any let me know.
Thank you.
=========================================================================
From: "Bottlehead" <Bottlehead@prodigy.net>
Subject: Re: Schulmerich Amplifier - Help
Date: Mon, 3 Nov 1997 07:24:30 -0800
Source: Sound Digest Archive v01.n098
Don,
I had pair of Schulmerich PP 805 booster amps (now dismantled).
They were set up for 45 ohms output impedance, and could also be rewired
for 180 ohms.
Doc B.
=========================================================================
From: jc morrison <jcm@eclipse.net>
Subject: schwarzkopf, bartok and chemical brothers
Date: Sat, 14 Mar 1998 02:20:24 -0800
Source: Sound Digest Archive v01.n217
i have been listening this morning to the rosenkavalier (the elizabet s.
performance), bartok's (sandor playing) concerto for piano and orchestra
#2 and the chem. bros. exit planet dust, all three recordings have
something in common that make them mortally difficult for a modest setup
to handle: huge dynamic changes. the bartok really is a problem because
the second movement has quietly humming strings against piano and
tympani only to be followed by the awesome bombast of the final
movement. i had to keep changing the volume level, i fucking hate that!
and while i have been contemplating a large horn system for this place
(i can fit a 30 ft. long 16' high bass horn in here...), there are
aspects of a large tall space that have prompted me to consider another
option. line array. i have an hunkering for a nearly omni (in this place
anyway...) high efficiency transducer. 16 5&1/4" drivers in a 7 ft.
line, in a sealed box 6" wide and 10" deep. the combined magnetic system
with the total piston area should move alot of air yet not get
unmanagedly directional (in the horizontal plane) until about 3000 hz,
where i can cross over to a ribbon. i'd want to do a 1" ribbon 7 ft.
tall, but can't afford the magnets yet (600 lbs. worth...). i'd like to
hear from those who have built tall arrays, open baffle and closed. i
have decided on the driver i'm going to use, but have not totally given
up on the dipole idea, although after re-reading olson i am tempted...
jc
=========================================================================
From: Chris Galbraith <chrisg@ducker.com>
Subject: Scope question...(damnit I *knew* I put that old e-mail somewhere )
Date: Wed, 29 Oct 1997 10:02:56 -0500
Source: Sound Digest Archive v01.n093
After all that great scope discussion a month ago, I'm shopping for one
and now can't find the posts!! Argh.
Could anyone give me some input on these two options-- a Tek 2215A
w/dual timebase (60MHz) for $310 in excellent shape, or a Tek 465M, very
good for $550. Any advice appreciated!!
- -Chris
=========================================================================
From: Michel Paquette <paqm01@GEL.USherb.CA>
Subject: Re: Scope question...(damnit I *knew* I put that old e-mail somewhere )
Date: Wed, 29 Oct 1997 13:10:29 -0400
Source: Sound Digest Archive v01.n094
>After all that great scope discussion a month ago, I'm shopping for one
>and now can't find the posts!! Argh.
>
>Could anyone give me some input on these two options-- a Tek 2215A
>w/dual timebase (60MHz) for $310 in excellent shape, or a Tek 465M, very
>good for $550. Any advice appreciated!!
>
>-Chris
The price of the 465 seems to going down recently. I went to a hamfest
and they were selling about 300$. They were about 400 - 500$ about a year
or two ago.
Just my thoughts.
Good scopes though.
Dunno about the 2215...
Michel
mailto:paqm01@gel.usherb.ca
http://www-edu.gel.usherb.ca/paqm01/
=========================================================================
From: Grego Sanguinetti <grego@latticesemi.com>
Subject: Re: Scope question...(damnit I *knew* I put that old e-mail somewhere )
Date: Wed, 29 Oct 1997 14:35:30 -0800 (PST)
Source: Sound Digest Archive v01.n094
> Could anyone give me some input on these two options-- a Tek 2215A
> w/dual timebase (60MHz) for $310 in excellent shape, or a Tek 465M, very
> good for $550. Any advice appreciated!!
The 2215A is fine but the 465 is better, in my opinion. You can do
better on the price though. I just saw one advertized recently for
just under 400. The M models are usually cheaper. Keep in mind though
that manuals for those can get expensive. The two scopes are about the
same size, nice and portable. I can't remember if the 2215A had on
screen readout or not? That is always nice.
- -grego
=========================================================================
From: Steve Van Osdell <svanos@toast.net>
Subject: Scott 355 tuner/preamp
Date: Fri, 07 Nov 1997 08:18:26 -0500
Source: Sound Digest Archive v01.n102
There was a fairly odd piece of Scott equipment made back around 1962 that
was the Scott 355 Tuner/Preamp. It would accept the Scott 208 80watt
amplifier as a mate by matching it up someway in the back.
The original cost of this little tuner/preamp was $320! This was quite
expensive during the era.
If anyone is familiar with this piece, can you shed some light on what you
know, good and bad, about this little unit.
Thanks, Steve
=========================================================================
From: Rick Francis <rfranci@uoft03.UTOLEDO.EDU>
Subject: Re: Scott 355 tuner/preamp
Date: Mon, 10 Nov 1997 18:14:26 -0500 (EST)
Source: Sound Digest Archive v01.n104
> There was a fairly odd piece of Scott equipment made back around 1962 that
> was the Scott 355 Tuner/Preamp. It would accept the Scott 208 80watt
> amplifier as a mate by matching it up someway in the back.
>
This tuner-preamp combo was not so unusual. In fact, I think most major
manufacturers offered one for a short period. I've got a busted Fisher
like this, and I've seen ads in the old mags for others. I don't think it
ever became hugely popular, though.
Rick Francis
=========================================================================
From: Torsten.Loesch@FinanceManager.Finance.FinanceAndInformation.enhar-ha.nthames.nhs.uk
Subject: Scott, Andre, Frank and Flame-War's - Hit the Delete Button NOW
Date: Thu, 25 Sep 1997 22:30:27 +0100
Source: Sound Digest Archive v01.n043
Hi,
May I humbly suggest that whoever gets involved into
the next Flame-War is nominated as "Guest of Honour"
for alt.flame?
That should cool them off.
I do not think that censorship (beyound self-censorship
that is) or removal of reasonable knowledgable but
sometimes hot-headed List-Members is that usefull.
We all have to simply learn to be a little bit more
reasonable, a little bit more tolerant and considerate.
That will help plenty.
Later
=========================================================================
From: Steve Van Osdell <svanos@toast.net>
Subject: Scott Grammer
Date: Sat, 22 Nov 1997 01:35:51 -0600
Source: Sound Digest Archive v01.n117
I tried phoning Scott Grammer today but got no answer. I don't know
exactly what is happening with him. I will try to find out. I hope he
gets things straightened out soon, he is missed. I don't even live in the
same town as him anymore.
Thanks, Steve
=========================================================================
From: STEVE CORNETT <SCORNETT@usagroup.com>
Subject: Scott Grammer
Date: Tue, 25 Nov 1997 08:25:29 -0600
Source: Sound Digest Archive v01.n119
Steve posted:
"...Hope everybody has a Happy Thanksgiving, and hope everyone is
thinking of Scott Grammer who is having hard times..."
What's the buzz, if it's not too personal?
Steve C.
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: Re: Scott Grammer
Date: Tue, 25 Nov 1997 09:53:07 -0800
Source: Sound Digest Archive v01.n119
Is there something that we can help Scott out with?? He did us all a
huge favour not so long ago by maintaining the list after Joe's
system bounced us. In fact, he was even nominated for Joenetter of
the year. Payback time??
Regards,
Ken Dangerfield
On 25 Nov 97 STEVE CORNETT said:
> Steve posted:
>
> "...Hope everybody has a Happy Thanksgiving, and hope everyone is
> thinking of Scott Grammer who is having hard times..."
>
> What's the buzz, if it's not too personal?
>
> Steve C.
>
>
>
=========================================================================
From: "Edward W. Johnson" <rb1304@alltel.net>
Subject: Scott Grammer
Date: Sun, 07 Dec 1997 22:49:33 -0500
Source: Sound Digest Archive v01.n128
Just wanted to let everyone Know Scott says Hello,I just talked to him
a while today.I've Known Scott for several years so he Knows how Im a
extreme parts scavenger.Told me hes got to clean house for the holidays
and he would be over to visit at the end of the week.
Anyone want to leave a message they can e-mail me privately and I'll be
sure to relay it.
=========================================================================
From: "Bottlehead" <Bottlehead@prodigy.net>
Subject: Scott tuner for sale
Date: Sun, 1 Feb 1998 08:57:34 -0800
Source: Sound Digest Archive v01.n178
I have a Scott LT-110-B tuner for sale.
All there, including a nice walnut cabinet with an easily filled hairline
on one corner, just missing the knobface on the tuning dial (but the
planetary tuning dial itself is not cracked, you Scott afficianados know
they usually are). All the lettering looks good.
I haven't even fired this baby up yet, but it looks like it's OK, fuse is
good, original Scott logo tubes, etc.
I will test her out later today, and determine a price, although I will
entertain offers over $80 plus shipping for as-is condition. Price will go
up if I start fooling with it, because I will clean the and oil the case,
clean the chassis, replace tubes, align it, etc.and probably double or more
the price, or decide to keep it for a while.
Sooo, if you are interested in a quick and dirty deal, e-mail me back. If
you don't know the Scott tuners, and want a history lesson and advice on
whether this would be a good tuner for you to buy at this time in your life
and considering the state of your existing system and marital status, be
forewarned that I will tell you yes, because I want to get rid of it.
Doc B.
yes we take plastic
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: scrap box special 6s4a + 5963
Date: Mon, 06 Jul 1998 17:21:15 -0700
Source: Sound Digest Archive v01.n334
Conrad Drake wrote:
>
> Rustling around in my scrap box I found a few unloved tubes which I thought I'd whip up into a "b
ench amp". The tubes are an RCA 6s4a (8w5 indHT triode ) and a Sylvania 5963 (12a*7 substitute).
>
> As I have a number of 275V/220uf caps that sets B+ at 200~250V, depending on what transformer I di
g up. [I have some 6ax4gtbs too, but they need 1.2A in the heaters vs 0.6 for the 6s4a, so I'll use
sillycon rectifiers).
>
> The GEC book says 26mA, 250V and 8V Vg for the 6S4A so a 310 ohm kathode bias resistor seems OK.
As mu is healthy I'll pass on the bypass cap for now. A cheap-n-nasty 30W 100V PA transformer wi
ll get the SE treatment. Rp is about 2K6 so I'll try the 5K and 10K taps.
My book says 3600 ohms at 26mA/250v. That's a VERY low&hot operating
point - you won't see more than 10-15% efficiency there, so maybe 1
watt out before grid current starts.
> 3V rms on the grid should push this well past the bounds of linearity, but the first watt or two s
hould be OK. Cmiller = 24pf so this is no problem.
Needs 8v/sqrt(2) or 5.5vRMS to get that first watt - which is also the
last watt...!
> The statement on the 5963 is a bit wierd (IMO):
> Vg=0 at 15mA & Vp=67.5V Low & hot or what?!
Probably rated this way for computer use as a flip-flop - does anybody
know?
> I'm tempted to drop this back to 5mA and Vp~= 125V & Vg~=10V. (Rk=2K, Ra=25K). I need a bi
t of gain here so an electrolytic Ck=120uf seems unavoidable.
rp is 6600 at 8.5mA, so a good operating point is 280v/8.5mA, load 20k
or so. I get 9.3 volts bias, or 1100 ohms Rk. At 5mA, go for at least
160 volts to get some decent voltage output capability.
Good luck! Please let us all know how it turns out - especially if my
calculations are wrong; they're just calculations after all, not real
data. (Incidentally, a local builder has used 6S4's in p-p and is very
happy with the result, so it must be at least a reasonable-sounding
tube...)
- -Paul Joppa
=========================================================================
From: "Conrad Drake" <conrad.drake@intellect.com.au>
Subject: scrap box special 6s4a + 5963
Date: Mon, 06 Jul 1998 21:58:18 +0800
Source: Sound Digest Archive v01.n334
Rustling around in my scrap box I found a few unloved tubes which I thought I'd whip up into a "ben
ch amp". The tubes are an RCA 6s4a (8w5 indHT triode ) and a Sylvania 5963 (12a*7 substitute).
As I have a number of 275V/220uf caps that sets B+ at 200~250V, depending on what transformer I dig
up. [I have some 6ax4gtbs too, but they need 1.2A in the heaters vs 0.6 for the 6s4a, so I'll use si
llycon rectifiers).
The GEC book says 26mA, 250V and 8V Vg for the 6S4A so a 310 ohm kathode bias resistor seems OK. As
mu is healthy I'll pass on the bypass cap for now. A cheap-n-nasty 30W 100V PA transformer will
get the SE treatment. Rp is about 2K6 so I'll try the 5K and 10K taps. 3V rms on the grid shou
ld push this well past the bounds of linearity, but the first watt or two should be OK. Cmiller = 2
4pf so this is no problem.
The statement on the 5963 is a bit wierd (IMO):
Vg=0 at 15mA & Vp=67.5V Low & hot or what?!
I'm tempted to drop this back to 5mA and Vp~= 125V & Vg~=10V. (Rk=2K, Ra=25K). I need a bit
of gain here so an electrolytic Ck=120uf seems unavoidable.
Coupling by 1uf polyprop and 100K gate pulldowns all round. Might just work. May just explode :-)
Anyone got any suggestions or comments? Or have curves for either device?
Conrad D
Hmmm, just noticed the 5963 says "JAN" which, if I correctly recall an earlier discussion, means "c
ould be anything which behaves as per this DoD contract" (#DSA900-69-D9081) N'est pas?
=========================================================================
From: "Conrad Drake" <conrad.drake@intellect.com.au>
Subject: Re: scrap box special 6s4a + 5963
Date: Tue, 07 Jul 1998 09:31:17 +0800
Source: Sound Digest Archive v01.n334
I wrote
>> As I have a number of 275V/220uf caps that sets B+ at 200~250V, depending on what transformer I d
ig up.
<snip>
>> The GEC book says 26mA, 250V and 8V Vg for the 6S4A so a 310 ohm kathode bias resistor seems OK.
>>As mu is healthy I'll pass on the bypass cap for now. A cheap-n-nasty 30W 100V PA transformer
will get the SE treatment. >>Rp is about 2K6 so I'll try the 5K and 10K taps.
Paul Joppa <pdj@ISDNseattle.net> said >>>
>My book says 3600 ohms at 26mA/250v. That's a VERY low&hot operating
>point - you won't see more than 10-15% efficiency there, so maybe 1
>watt out before grid current starts.
So I'll try the 10K tap.
>> 3V rms on the grid should push this well past the bounds of linearity, but the first watt or two
should be OK.
>Needs 8v/sqrt(2) or 5.5vRMS to get that first watt - which is also the
>last watt...!
Eeep! Maybe I should add the Ck after all? As without it I'm going to get some degeneration from t
he Rk. Might help the linearity but I guess that would count as deliberate feedback. I'll have to
see how it sounds :-)
<snap>
>> I'm tempted to drop this back to 5mA and Vp~= 125V & Vg~=10V. (Rk=2K, Ra=25K). I need a b
it of gain
>> here so an electrolytic Ck=120uf seems unavoidable.
>rp is 6600 at 8.5mA, so a good operating point is 280v/8.5mA, load 20k
>or so. I get 9.3 volts bias, or 1100 ohms Rk. At 5mA, go for at least
>160 volts to get some decent voltage output capability.
Thanks, I'll try that. Ra=16K to B+ = 250V should do the trick.
>Good luck! Please let us all know how it turns out - especially if my
>calculations are wrong; they're just calculations after all, not real
>data.
I've been guessing so far, so your calculations are a massive improvement on that!!!
>(Incidentally, a local builder has used 6S4's in p-p and is very
>happy with the result, so it must be at least a reasonable-sounding
>tube...)
Think I paid a whole dollar ($US 0.53) for it so if it sings at 1/2 watt I'll be verry happy.
Yours,
Conrad D
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: screen drive amp
Date: Thu, 14 May 1998 11:24:09 PDT
Source: Sound Digest Archive v01.n278
Hi there,
>remember this, from a few months back....
>
>http://www.svetlana.com/technoteNO.33.html
Nice one Bob. I like it. I need a Poweramp Project....
I'll probably use the Driver-Circuit from Tim de'Paravicini's EAR859
though.
How would anyone think would this thing come out using the realy cheap'n
nasty Audionote 2.5k 15 Output (okay I take the nasty back - it's
probably quite good noting the price....).
Has anyone made an Amp besed on this OPT? How is it?
Later Thorsten
Ps. Bob, how about doing some work at Svetlana to make a working PSpice
Library (within the Eval Versions Device-Limits) including all Symbols
and the like available (on Disk and for download from the net - usual
disclaimer apply of course). It would make life a bit easier. I still
have not managed to work out how to include the EL509 for my Library....
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: screen drive amp
Date: Thu, 14 May 1998 13:26:08 -0400
Source: Sound Digest Archive v01.n278
hey guys,
remember this, from a few months back....
http://www.svetlana.com/technoteNO.33.html
bob.d.
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: RE: screen drive amp
Date: Thu, 14 May 1998 16:52:21 -0400
Source: Sou