Sound Practices Mailing List Files - Volume 2
=========================================================================
From: Steve Berger <aprilsound@earthlink.net>
Subject: [JN] 604s Thanx to all!!
Date: Sat, 06 Feb 1999 23:48:11 -0500
Source: Sound Digest Archive v02.n031
This is a multi-part message in MIME format.
- --------------110911B85B10
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
- --
Steve Berger <http://home.earthlink.net/~aprilsound/>
- --------------110911B85B10
Content-Type: message/rfc822
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Received: from localhost (localhost)
by ostrich.prod.itd.earthlink.net (8.8.7/8.8.5) with internal id PYR07223;
Sat, 6 Feb 1999 19:26:35 -0800 (PST)
Date: Sat, 6 Feb 1999 19:26:35 -0800 (PST)
From: Mail Delivery Subsystem <MAILER-DAEMON>
Message-Id: <199902070326.PYR07223@ostrich.prod.itd.earthlink.net>
To: <aprilsound@earthlink.net>
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="PYR07223.918357995/ostrich.prod.itd.earthlink.net"
Subject: Returned mail: Host unknown (Name server: delivorator.io.com: host not found)
Auto-Submitted: auto-generated (failure)
This is a MIME-encapsulated message
- --PYR07223.918357995/ostrich.prod.itd.earthlink.net
The original message was received at Sat, 6 Feb 1999 12:29:31 -0800 (PST)
from hawk.prod.itd.earthlink.net [207.217.120.22]
----- The following addresses had permanent fatal errors -----
<sound@delivorator.io.com>
----- Transcript of session follows -----
550 <sound@delivorator.io.com>... Host unknown (Name server: delivorator.io.com: host not found)
- --PYR07223.918357995/ostrich.prod.itd.earthlink.net
Content-Type: message/delivery-status
Reporting-MTA: dns; ostrich.prod.itd.earthlink.net
Arrival-Date: Sat, 6 Feb 1999 12:29:31 -0800 (PST)
Final-Recipient: RFC822; sound@delivorator.io.com
Action: failed
Status: 5.1.2
Remote-MTA: DNS; delivorator.io.com
Last-Attempt-Date: Sat, 6 Feb 1999 19:26:35 -0800 (PST)
- --PYR07223.918357995/ostrich.prod.itd.earthlink.net
Content-Type: message/rfc822
Received: from hawk.prod.itd.earthlink.net (hawk.prod.itd.earthlink.net [207.217.120.22])
by ostrich.prod.itd.earthlink.net (8.8.7/8.8.5) with ESMTP id MAA00224
for <sound@delivorator.io.com>; Sat, 6 Feb 1999 12:29:31 -0800 (PST)
Received: from steveber (ip56.an3-new-york4.ny.pub-ip.psi.net [38.26.14.56])
by hawk.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id MAA27093
for <sound@delivorator.io.com>; Sat, 6 Feb 1999 12:29:30 -0800 (PST)
Message-ID: <36BCA749.6EF@earthlink.net>
Date: Sat, 06 Feb 1999 15:34:17 -0500
From: Steve Berger <aprilsound@earthlink.net>
Reply-To: aprilsound@earthlink.net
X-Mailer: Mozilla 3.01 (Win95; I)
MIME-Version: 1.0
To: sound@delivorator.io.com
Subject: [Fwd: Returned mail: Host unknown (Name server: deliverato.io.com: host not found)]
Content-Type: multipart/mixed; boundary="------------540C512B6FB"
This is a multi-part message in MIME format.
- --------------540C512B6FB
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
- --
Steve Berger <http://home.earthlink.net/~aprilsound/>
- --------------540C512B6FB
Content-Type: message/rfc822
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Received: from localhost (localhost)
by ostrich.prod.itd.earthlink.net (8.8.7/8.8.5) with internal id JCU21327;
Sat, 6 Feb 1999 09:26:39 -0800 (PST)
Date: Sat, 6 Feb 1999 09:26:39 -0800 (PST)
From: Mail Delivery Subsystem <MAILER-DAEMON>
Message-Id: <199902061726.JCU21327@ostrich.prod.itd.earthlink.net>
To: <aprilsound@earthlink.net>
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="JCU21327.918321999/ostrich.prod.itd.earthlink.net"
Subject: Returned mail: Host unknown (Name server: deliverato.io.com: host not found)
Auto-Submitted: auto-generated (failure)
This is a MIME-encapsulated message
- --JCU21327.918321999/ostrich.prod.itd.earthlink.net
The original message was received at Sat, 6 Feb 1999 08:49:57 -0800 (PST)
from goose.prod.itd.earthlink.net [207.217.120.18]
----- The following addresses had permanent fatal errors -----
<sound@deliverato.io.com>
----- Transcript of session follows -----
550 <sound@deliverato.io.com>... Host unknown (Name server: deliverato.io.com: host not found)
- --JCU21327.918321999/ostrich.prod.itd.earthlink.net
Content-Type: message/delivery-status
Reporting-MTA: dns; ostrich.prod.itd.earthlink.net
Arrival-Date: Sat, 6 Feb 1999 08:49:57 -0800 (PST)
Final-Recipient: RFC822; sound@deliverato.io.com
Action: failed
Status: 5.1.2
Remote-MTA: DNS; deliverato.io.com
Last-Attempt-Date: Sat, 6 Feb 1999 09:26:39 -0800 (PST)
- --JCU21327.918321999/ostrich.prod.itd.earthlink.net
Content-Type: message/rfc822
Received: from goose.prod.itd.earthlink.net (goose.prod.itd.earthlink.net [207.217.120.18])
by ostrich.prod.itd.earthlink.net (8.8.7/8.8.5) with ESMTP id IAA20869
for <sound@deliverato.io.com>; Sat, 6 Feb 1999 08:49:57 -0800 (PST)
Received: from steveber (ip185.an5-new-york4.ny.pub-ip.psi.net [38.26.16.185])
by goose.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id IAA03758
for <sound@deliverato.io.com>; Sat, 6 Feb 1999 08:49:56 -0800 (PST)
Message-ID: <36BC73D2.5D95@earthlink.net>
Date: Sat, 06 Feb 1999 11:54:42 -0500
From: Steve Berger <aprilsound@earthlink.net>
Reply-To: aprilsound@earthlink.net
X-Mailer: Mozilla 3.01 (Win95; I)
MIME-Version: 1.0
To: sound@deliverato.io.com
Subject: 604s Thanx to all!!!
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Hi all:
Thanx to everyone for there help.
so far, I have only tried a 1st order xover on the woofer@1k, and a
third order @ 1600 on the horn. I think that I need to close the gap a
bit, but I dont have much hope. I also think that I'm going to have to
wind those annoying tapped inductors for the ML style x-over.
Anyway,Thanx alot.
Steve
- --
Steve Berger <http://home.earthlink.net/~aprilsound/>
- --JCU21327.918321999/ostrich.prod.itd.earthlink.net--
- --------------540C512B6FB--
- --PYR07223.918357995/ostrich.prod.itd.earthlink.net--
- --------------110911B85B10--
=========================================================================
From: Tim Reese <tgrmail@nmr.MGH.harvard.EDU>
Subject: [JN] 6072 brand difference?
Date: Sat, 13 Nov 1999 16:21:17 -0500 (EST)
Source: Sound Digest Archive v02.n331
Anybody notice any brand difference between 6072s? How about difference
in GE 5-stars vs. plain GE?
tia tr
- ----------------------------------------------------------------------
Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu
=========================================================================
From: SBench@aol.com
Subject: Re: [JN] 6072 brand difference?
Date: Sun, 14 Nov 1999 15:32:23 EST
Source: Sound Digest Archive v02.n332
In a message dated 99-11-13 16:28:12 EST, tgrmail@nmr.MGH.harvard.EDU writes:
<<
Anybody notice any brand difference between 6072s? How about difference
in GE 5-stars vs. plain GE?
tia tr
----------------------------------------------------------------------
Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu >>
Hi Tim,
My selection of those are
6072 5 star GE
6072A 5 star GE
12AY7 GE
JAN 6072A, made by GE, not listed as 5 star
12AY7 National. Made by ?
There are 4 construction techniques (and variants of those) in those
items. The 6072/6072A appear to be the same basic construction with
variants over the years in the plate support to mica, heater center tap
and minor support changes. (in one variant, the heater CT has a stud
that pushes up to and supports(?) the lower mica).
These all sound fairly similar. The 6072s test about the same
as the 6072As, although the 6072As have less variation. The current
sample size is about 15 tubes of this type, so the differences may
not be statistically significant.
Interestingly, the quietest tubes also are LIGHT SENSITIVE (!) Be
sure to cover the tube with something opaque.
The JAN 6072 (GEs) appear to be similar variants, with minor
construction differences. (Only have 2 examples).
The GE 12AY7 is a different construction, not having any "wings"
on the plates. They sound OK, maybe slightly less "accurate"
(as best as I can describe it), and they are slightly noisier, but
that may be limited by the sample size (about 6).
The National are grey plate devices, and do not sound (to my ears)
as good. Measure about the same from a noise perspective, but
are slightly more microphonic. (Have only 4 of these, so sample
size is again limited).
Best Regards,
Steve
=========================================================================
From: S.C.Busbridge@bton.ac.uk
Subject: [JN] 6080 Amplifier?
Date: Thu, 23 Aug 2001 09:27:32 +0100
Source: Sound Digest Archive v02.n953
Hello
Does anyone have any experience of using the 6080 in a SET amplifier? What
about fixed bias, with the RCA manual does not recommend?
TIA
Simon
Simon Busbridge, BSc(Hons) PhD CPhys MInstP
School of Engineering
University of Brighton
Lewes Road
Moulsecoomb
Brighton BN2 4GJ
UNITED KINGDOM
Tel: 0044 (0)1273 642542
Fax: 0044 (0)1273 642327/642301
e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com
Audio www site: http://audio.eng.bton.ac.uk
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] 6080 Amplifier?
Date: Thu, 23 Aug 2001 09:27:38 -0400
Source: Sound Digest Archive v02.n953
Bjorn Kolbrek wrote:
> http://www.svetlana.com/docs/TechBulletins/TB.html. 6080 is a 6AS7 with
> higher heater voltage.
Actually, the 6080 has the same heater voltage/current. 6082 is the
same sube with a higher heater voltage (26.5V/0.6A)
Peace--
Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe
"Once in a while you get shown the light
In the strangest of places if you look at it right." Robert Hunter
"640K ought to be enough for anybody" , Bill Gates, 1981
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 6080 Amplifier?
Date: Thu, 23 Aug 2001 10:23:24 -0400
Source: Sound Digest Archive v02.n953
My friend Bruce Wenger has used 6080s with fixed bias for years now with
no problem. I know the 6336 requires a minimum cathode voltage for
fixed bias, like 10%--I put 100 ohms on the cathode and that seems to
take care of it.
- --
Grover Gardner
groverg@postoffice.att.net
Visit my web site at http://home.att.net/~groverg/homepage.htm
=========================================================================
From: Bjorn Kolbrek <bjornk@studpors.hit.no>
Subject: Re: [JN] 6080 Amplifier?
Date: Thu, 23 Aug 2001 12:14:24 +0200
Source: Sound Digest Archive v02.n953
At 09:27 23.08.01 +0100, you wrote:
>Hello
>
>Does anyone have any experience of using the 6080 in a SET amplifier? What
>about fixed bias, with the RCA manual does not recommend?
Check out the article "Maximum Sound Quality from a Single 6AS7" at
Svetlanas technical pages,
http://www.svetlana.com/docs/TechBulletins/TB.html. 6080 is a 6AS7 with
higher heater voltage.
Bjørn
- -------------------------------------------------
__/\__
/ ____ \ Bjørn Kolbrek
| | || | |
| | || | | bjornk@studpors.hit.no
| | || | | http://www.geocities.com/la1zka
| | || | |
| |____| |
| /||||\ |
--------
| | | |
- -------------------------------------------------
=========================================================================
From: Christian Rintelen <christian@rintelen.ch>
Subject: Re: [JN] 6080 Amplifier?
Date: Thu, 23 Aug 2001 17:59:06 +0200
Source: Sound Digest Archive v02.n953
I'm using my 6080 P-P amps with a mixture of cathode and fixed bias. Works
well and w/o the least trouble. (Don't ask me about the operating points -
I don't know anymore and I'm too lazy/busy to check. Something like 250 V
B+, approx -60 V bias and 2k2 p2p OPTs into 16 ohms IIRC)
Đ
Grover Gardner wrote:
> My friend Bruce Wenger has used 6080s with fixed bias for years now with
> no problem. I know the 6336 requires a minimum cathode voltage for
> fixed bias, like 10%--I put 100 ohms on the cathode and that seems to
> take care of it.
=========================================================================
From: S.C.Busbridge@bton.ac.uk
Subject: RE: [JN] 6080 Amplifier
Date: Tue, 28 Aug 2001 11:20:50 +0100
Source: Sound Digest Archive v02.n955
Thanks to everyone who resonded.
Does anyone have information on the 6080 amp HiFi World did a few years ago?
Simon
Simon Busbridge, BSc(Hons) PhD CPhys MInstP
School of Engineering
University of Brighton
Lewes Road
Moulsecoomb
Brighton BN2 4GJ
UNITED KINGDOM
Tel: 0044 (0)1273 642542
Fax: 0044 (0)1273 642327/642301
e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com
Audio www site: http://audio.eng.bton.ac.uk
=========================================================================
From: "Chris Vryonides" <chrisvryonides@hotmail.com>
Subject: RE: [JN] 6080 Amplifier
Date: Tue, 28 Aug 2001 12:12:54 +0000
Source: Sound Digest Archive v02.n955
Hi Simon
I have the original supplement from about 6 or 7 years back, but it's at my
folks home, so I won't be able to get it for a few weeks.
From v. rusty memory, I think it ran the 6080s at about 250-300V, SE. Driver
was ECC88 cascode, power 3W, plenty of feedback, design by de Paravicini.
You want me to dig it out next time I'm visiting them? 833 amp running a tad
too hot for this (lost the plot) summer weather?
Cheers
Chris
>>>>Does anyone have information on the 6080 amp HiFi World did a few years
>>>>ago?
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
=========================================================================
From: S.C.Busbridge@bton.ac.uk
Subject: [JN] 6080 amplifier - information
Date: Wed, 29 Aug 2001 10:44:33 +0100
Source: Sound Digest Archive v02.n956
Hello
Thanks to all those who responded. Here's what I have found out after
looking around and 'messing' around with a lash up:
1) The current is _very_ sensitive to both bias voltage and HT voltage.
2) The low impedance of the valve makes it ideally suited to wide bandwidth
operation. I came across one (push pull) design using a 6J7 driver feeding
into a 1:2+2 transformer. It seems to me that this driver will limit the
bandwidth of the whole amplifier
3) Fixed bias operation seems stable, in spite of what the RCA manual
suggests. However I have put 33 R in each cathode which will help against
runaway. Maybe there will be a problem with changes in mains voltage?
4) SRPP is quite capable of driving this valve to its full extent. I
started with the 6SL7 but it could not drive the 100 K grid resistor, so I
now have a E86C and EF184 combination which drives and is more linear. The
6080 is actually quite linear for a regulator valve.
5) Clipping occurs at 6 - 7 W (parallel operation) with 240 V anode HT and
100 mA total current. Bias is -125 V and the anode load in my set up is
2,500 R
6) The two halves of about half of my 6080s are matched to within 10%, the
other half are way out. I am thinking of having a single bias control and
selecting for internal matching. They are cheap enough to do this.
Alternatively it is not difficult to put separate bias controls for each
half.
The reason for my interest is to build an amplifier to drive tweeters,
putting the crossover in the low signal path. A low impedance valve is
therefore essential. I do not want to go to the expense of a DHT amp just
yet with the price of globe tubes going up and up...
Best,
Simon
Simon Busbridge, BSc(Hons) PhD CPhys MInstP
School of Engineering
University of Brighton
Lewes Road
Moulsecoomb
Brighton BN2 4GJ
UNITED KINGDOM
Tel: 0044 (0)1273 642542
Fax: 0044 (0)1273 642327/642301
e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com
Audio www site: http://audio.eng.bton.ac.uk
=========================================================================
From: SBench@aol.com
Subject: [JN] 6088 Preamp Progress Report
Date: Tue, 9 May 2000 00:02:42 EDT
Source: Sound Digest Archive v02.n542
Hi Joes,
Well, I've got about 20 hours of listening on the phono section.
Measures: FLAT. (about 0.5dB down at 10Hz and 40kHz.)
Noise: About 1-2uV equivalent input noise, which isn't spectacular
as far as quietness goes, but not bad considering the aenemic
little tubes. Reasonable noise level.
Gain: 34dB gain at 1kHz.
Sounds like a pentode(!)
Power consumption: 1.5V@72mA, 72V@<2mA.
Interestingly, the microphonics are *very* hi Q and relatively low level.
There's a sharp peak at about 3.5kHz that produces a TONE when you
whack the box. [Yeah, I know... don't whack the box].
RIAA5 has nothing to be particularly to be worried about (except for size
and power consumption).
I'll hold off judgement until I get the whole line section completed.
I will update my web page with PART 2 of the battery preamp series
sometime later this week [containing preamp overview/block/schematic,
power distribution schematic, and phono section schematic]. If anyone
wants a copy of the schematic earlier than that (they're done now... just
haven't prepared the HTML article yet), EMail me.
Best Regards,
Steve
=========================================================================
From: Kurt Steffensen <kurt-steffensen@teliamail.dk>
Subject: Re: [JN] 6088 Preamp Progress Report
Date: Tue, 09 May 2000 14:23:57 +0300
Source: Sound Digest Archive v02.n542
There is many very interesting and remarkable personalities amongst the Joes.
But one that keeps amazing me is , Steve.
I wonder if you are all aware about , just how much he manage to get by
through his hands..?
He even offered to push a set of speakers over here !!
And again , something he just put together , with things at hand ! :-)
( Probably for a one day audition , outside home ;-)
And all in his spare time. He has a demanding full time job as well , to take
care of.
Take a look at his home page , if you do not know just what I mean.
It is the website , to any tube interested person in the world.
I guess , Steve , just one day decided that he needed something small and
light weighted for the summer meeting.
It had to be pocket size , in order to be with the hand luggage in the
plane.....
And hence , this wonderful little tubed battery thing was a reality :-)
Amazing...Just amazing..
SBench@aol.com wrote:
> Noise: About 1-2uV equivalent input noise, which isn't spectacular
> as far as quietness goes, but not bad considering the aenemic
> little tubes. Reasonable noise level.
Considering the 2 mA drawn , and that all the B+ is a series of cells , I
would even dare to call that very low noise indeed ....
I know of many well respected pre amps , that produces a hell lot more of
noise.
And none of the noise in this amp is hum related.. - Cool :-)
> Gain: 34dB gain at 1kHz.
> Sounds like a pentode(!)
But as you say yourself , it is a pentode ;-)
> Interestingly, the microphonics are *very* hi Q and relatively low level.
> There's a sharp peak at about 3.5kHz that produces a TONE when you
> whack the box. [Yeah, I know... don't whack the box].
I do not think we have to worry much about this problem.
I do not doubt that you will solve it , just as you solve anything else ,
that comes your way.
Thanks a lot for all you kind effort , Steve.
All of our Joes really appreciate all you do.
- - Kurt
=========================================================================
From: longrie@mmace.nrl.navy.mil
Subject: Re: [JN] 6088 Preamp Progress Report
Date: Thu, 11 May 2000 18:33:37 +0100
Source: Sound Digest Archive v02.n543
Kurt,
Can you imagine that Steve's best work is still ahead!
regards
gary
"Non fui, non sum, non curo"
- patrick obrian
master and commander
>There is many very interesting and remarkable personalities amongst the Joes.
>
>But one that keeps amazing me is , Steve.
>
>I wonder if you are all aware about , just how much he manage to get by
>through his hands..?
>He even offered to push a set of speakers over here !!
>And again , something he just put together , with things at hand ! :-)
>( Probably for a one day audition , outside home ;-)
>
>And all in his spare time. He has a demanding full time job as well , to take
>care of.
>Take a look at his home page , if you do not know just what I mean.
>It is the website , to any tube interested person in the world.
>
>I guess , Steve , just one day decided that he needed something small and
>light weighted for the summer meeting.
>It had to be pocket size , in order to be with the hand luggage in the
>plane.....
>And hence , this wonderful little tubed battery thing was a reality :-)
>Amazing...Just amazing..
>
>SBench@aol.com wrote:
>
>> Noise: About 1-2uV equivalent input noise, which isn't spectacular
>> as far as quietness goes, but not bad considering the aenemic
>> little tubes. Reasonable noise level.
>
>Considering the 2 mA drawn , and that all the B+ is a series of cells , I
>would even dare to call that very low noise indeed ....
>I know of many well respected pre amps , that produces a hell lot more of
>noise.
>and none of the noise in this amp is hum related.. - Cool :-)
>
>> Gain: 34dB gain at 1kHz.
>> Sounds like a pentode(!)
>
>But as you say yourself , it is a pentode ;-)
>
>> Interestingly, the microphonics are *very* hi Q and relatively low level.
>> There's a sharp peak at about 3.5kHz that produces a TONE when you
>> whack the box. [Yeah, I know... don't whack the box].
>
>I do not think we have to worry much about this problem.
>I do not doubt that you will solve it , just as you solve anything else ,
>that comes your way.
>
>Thanks a lot for all you kind effort , Steve.
>All of our Joes really appreciate all you do.
>
>- - Kurt
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146/6146B & 3C33
Date: Thu, 3 Feb 2000 17:11:15 -0000
Source: Sound Digest Archive v02.n432
Thanks Daniel,
I'll look out for them, though I've a nasty feeling it could be another
"Indian Rope Trick - like the 3C33 here in England!
Regards,
Paul
- ----- Original Message -----
From: Daniel J. Marshall <danmarshall@worldnet.att.net>
To: Joenet <sound@lists.io.com>
Sent: Thursday, February 03, 2000 12:48 AM
Subject: Re: [JN] 6146/6146B
> You might consider trying some CK6293s. They look identical to 6146s,
> but have much higher screen voltage ratings. I have a NOS quad I picked
> up for cheap, but I have not tried them.
>
> DM
>
>
> > I have rather fallen in love with the squat and beefy 6146.
> >
> > Have any of you chaps given it some stick and run it as a triode,
substantially
> > above its maximum G2 voltage of 250V? I have in mind about 400V!
> >
> > I'll bet it would make a lovely triode if it could stand it!
> >
> > Paul
> >
>
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: [JN] 6146/6146B
Date: Wed, 02 Feb 2000 16:48:13 -0800
Source: Sound Digest Archive v02.n431
You might consider trying some CK6293s. They look identical to 6146s,
but have much higher screen voltage ratings. I have a NOS quad I picked
up for cheap, but I have not tried them.
DM
> I have rather fallen in love with the squat and beefy 6146.
>
> Have any of you chaps given it some stick and run it as a triode, substantially
> above its maximum G2 voltage of 250V? I have in mind about 400V!
>
> I'll bet it would make a lovely triode if it could stand it!
>
> Paul
>
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] 6146/6146B
Date: Wed, 02 Feb 2000 19:35:02 -0500
Source: Sound Digest Archive v02.n431
"P. de R. L." wrote:
> I have rather fallen in love with the squat and beefy 6146. Have any
> of you chaps given it some stick and run it as a triode, substantially
> above its maximum G2 voltage of 250V? I have in mind about 400V! I'll
> bet it would make a lovely triode if it could stand it! Paul
Hi
I never tried it as a triode but I have used it in a power amp some time
ago, also the early versions of the Ampeg SVT used it. It is a mobile
rated (mechanically rugged, thick glass) Short wave frequency range
transmitter tube. Being made for Single Side Band operation, it is more
linear (I was told by a transmitter guy) than normal (AM) power tubes.
Do try its a neat tube, a little less than a 6550 but more than its
conservative ratings suggest (and you got to love plate caps too).
Tom
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: [JN] 6146/6146B
Date: Wed, 2 Feb 2000 23:55:38 -0000
Source: Sound Digest Archive v02.n431
This is a multi-part message in MIME format.
- ------=_NextPart_000_0017_01BF6DD9.012FBDA0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
I have rather fallen in love with the squat and beefy 6146.
Have any of you chaps given it some stick and run it as a triode, =
substantially above its maximum G2 voltage of 250V? I have in mind =
about 400V!
I'll bet it would make a lovely triode if it could stand it!
Paul
- ------=_NextPart_000_0017_01BF6DD9.012FBDA0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content=3D"text/html; charset=3Diso-8859-1" =
http-equiv=3DContent-Type>
<META content=3D"MSHTML 5.00.2314.1000" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#800080 face=3D"Century Schoolbook" size=3D2>I have =
rather fallen=20
in love with the squat and beefy 6146.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT color=3D#800080 face=3D"Century Schoolbook" size=3D2>Have any =
of you chaps=20
given it some stick and run it as a triode, substantially above its =
maximum G2=20
voltage of 250V? I have in mind about 400V!</FONT></DIV>
<DIV> </DIV>
<DIV><FONT color=3D#800080 face=3D"Century Schoolbook" size=3D2>I'll bet =
it would make=20
a lovely triode if it could stand it!</FONT></DIV>
<DIV> </DIV>
<DIV><FONT color=3D#800080 face=3D"Century Schoolbook"=20
size=3D2>Paul</FONT></DIV></BODY></HTML>
- ------=_NextPart_000_0017_01BF6DD9.012FBDA0--
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146/6146B
Date: Thu, 3 Feb 2000 17:09:26 -0000
Source: Sound Digest Archive v02.n432
Thanks Thomas.
I will chance it - I may persuade a chap I know to test a secondhand one to
destruction first!
Plate caps? No problem I have a push-pull 813 amplifier I built!
regards,
Paul
- ----- Original Message -----
From: Thomas Danley <Tom@ppci.com>
To: P. de R. L. <triode@bow-tie.org.uk>
Cc: Joenet <sound@deliverator.io.com>
Sent: Thursday, February 03, 2000 12:35 AM
Subject: Re: [JN] 6146/6146B
>
>
> "P. de R. L." wrote:
>
> > I have rather fallen in love with the squat and beefy 6146. Have any
> > of you chaps given it some stick and run it as a triode, substantially
> > above its maximum G2 voltage of 250V? I have in mind about 400V! I'll
> > bet it would make a lovely triode if it could stand it! Paul
>
> Hi
> I never tried it as a triode but I have used it in a power amp some time
> ago, also the early versions of the Ampeg SVT used it. It is a mobile
> rated (mechanically rugged, thick glass) Short wave frequency range
> transmitter tube. Being made for Single Side Band operation, it is more
> linear (I was told by a transmitter guy) than normal (AM) power tubes.
> Do try its a neat tube, a little less than a 6550 but more than its
> conservative ratings suggest (and you got to love plate caps too).
>
> Tom
>
>
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: [JN] 6146/6146B
Date: Fri, 4 Feb 2000 13:25:05 -0500
Source: Sound Digest Archive v02.n433
RE: [JN] 6146/6146B
Paul asks:
>>>Have any of you chaps given it some stick and run it as a triode,
substantially above its maximum G2 voltage of 250V? I have in mind about
400V!
I'll bet it would make a lovely triode if it could stand it!<<<
It burns, brother, burns!
But you can use a series resistor to keep the G2 voltage to what the
designer intended - could be bigger than you might expect.
The same goes for the EL/PL519 line output tubes - inexpensive, very rugged
and not at all bad sounding as triodes when used this way.
Allen (VSE)
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] 6146/6146B
Date: Fri, 04 Feb 2000 18:39:56 GMT
Source: Sound Digest Archive v02.n434
Hi all,
>The same goes for the EL/PL519 line output tubes - inexpensive, very rugged
>and not at all bad sounding as triodes when used this way.
Even better, they are in current production and they also feature the all
important topcap connection (Paul really does like his Topcap's)....
Then again, I suspect like the other interresting penthodes they really like
G2 Drive. How about a Stepdown Interstage Transformer to drive the G2's or
your 813's Paul?
Later Thorsten
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146/6146B
Date: Fri, 4 Feb 2000 19:38:37 -0000
Source: Sound Digest Archive v02.n434
hello Thorsten.
Thanks for that original idea. It's a pity transformers are so expensive.
Could I drive them of the anodes of my A2293s? (ra 375 ohms)?
Actually Daniel Marshall has come up with an exciting NEW valve (you know
how I like these) This is the CK 6293. (A Raytheon number I think). Now
this one's a corker - looks like a 6146 but can apparently take proper volts
on its G2.
Where do I find them?
By the way, J111 is a flop. after checking everything and trying 5687 and
7119 the grounded grid side of the diff pair is STILL 3.5dB down. There's
nothing left to check. I need a 30mA Jfet with high impedance.
Regards,
Paul
- ----- Original Message -----
From: T. Loesch <ezee_e@hotmail.com>
To: <AllenVSE@compuserve.com>; <sound@lists.io.com>
Sent: Friday, February 04, 2000 6:39 PM
Subject: Re: [JN] 6146/6146B
> Hi all,
>
> >The same goes for the EL/PL519 line output tubes - inexpensive, very
rugged
> >and not at all bad sounding as triodes when used this way.
>
> Even better, they are in current production and they also feature the all
> important topcap connection (Paul really does like his Topcap's)....
>
> Then again, I suspect like the other interresting penthodes they really
like
> G2 Drive. How about a Stepdown Interstage Transformer to drive the G2's or
> your 813's Paul?
>
> Later Thorsten
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
>
>
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] 6146/6146B
Date: Fri, 04 Feb 2000 19:55:06 GMT
Source: Sound Digest Archive v02.n434
Hi there,
>Thanks for that original idea. It's a pity transformers are so expensive.
Isn't it just.
>Could I drive them of the anodes of my A2293s? (ra 375 ohms)?
The problem is that G2 Drive needs substantial grid current under all
conditions. The advantage is that the G2 must be moved up quite high in
Voltage making a fully DC coupled Amplifier possible.... Imagine, no
expensive Capacitors or Transformers, only Valves....
>By the way, J111 is a flop. after checking everything and trying 5687 and
>7119 the grounded grid side of the diff pair is STILL 3.5dB down.
Darn.
Tell you what Paul. Cascode the J111.... Stack one on top of the other. Gate
of the upper one goes to the source of the other one. That should increase
the Impedance.
The other option is to see is you can get at least 5V negative Voltage and
use that with a 2SK147 where the Gate is tied to ground (gives you about 5V
additional Volts to play and essentially "overdrive" the gate of the FET.
Later Thorsten
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146/6146B
Date: Fri, 4 Feb 2000 20:25:12 -0000
Source: Sound Digest Archive v02.n434
Thanks, Thorsten.
I'll try the cascode suggestion first; I just hat having to install a -15V
supply for one sink!
regards,
paul
- ----- Original Message -----
From: T. Loesch <ezee_e@hotmail.com>
To: <triode@bow-tie.org.uk>; <Thorsten@tnt-audio.com>;
<AllenVSE@compuserve.com>; <sound@lists.io.com>
Sent: Friday, February 04, 2000 7:55 PM
Subject: Re: [JN] 6146/6146B
> Hi there,
>
> >Thanks for that original idea. It's a pity transformers are so
expensive.
>
> Isn't it just.
>
> >Could I drive them of the anodes of my A2293s? (ra 375 ohms)?
>
> The problem is that G2 Drive needs substantial grid current under all
> conditions. The advantage is that the G2 must be moved up quite high in
> Voltage making a fully DC coupled Amplifier possible.... Imagine, no
> expensive Capacitors or Transformers, only Valves....
>
> >By the way, J111 is a flop. after checking everything and trying 5687
and
> >7119 the grounded grid side of the diff pair is STILL 3.5dB down.
>
> Darn.
>
> Tell you what Paul. Cascode the J111.... Stack one on top of the other.
Gate
> of the upper one goes to the source of the other one. That should increase
> the Impedance.
>
> The other option is to see is you can get at least 5V negative Voltage and
> use that with a 2SK147 where the Gate is tied to ground (gives you about
5V
> additional Volts to play and essentially "overdrive" the gate of the FET.
>
> Later Thorsten
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
>
>
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146/6146B
Date: Fri, 4 Feb 2000 21:47:00 -0000
Source: Sound Digest Archive v02.n434
I know nothinks of the PL519.
I just wanted to know if i could give the 6146 a good "bating" as a triode;
sadly it seems not!
Paul
- ----- Original Message -----
From: Hugh R. Dean <aspen@alphalink.com.au>
To: <Thorsten@tnt-audio.com>; Joenet <sound@deliverator.io.com>
Sent: Friday, February 04, 2000 8:56 PM
Subject: Re: [JN] 6146/6146B
> This tube is up for discussion:
>
> >The same goes for the EL/PL519 line output tubes - inexpensive, very
> rugged
> > >and not at all bad sounding as triodes when used this way.
> >
> > Even better, they are in current production and they also feature the
all
> > important topcap connection (Paul really does like his Topcap's)....
>
> A year ago I auditioned a de Paravicini SE stereo, integrated amp which
used
> this tube. Speakers were a Jericho horn with Fostex 208 sigma, and Denon
> 1015 CD player (average; not outstanding).
>
> I, and two others, felt there was a strange metallic sheen on top of
female
> vocals. I'm curious to know if this was the PL519 or the amp design.
(Tim
> uses multi-path feedback, I understand, and this is famous for multiple
> poles, which could explain it I guess.)
>
> Any opinions?
>
> Hugh R. Dean
> Melbourne, Australia
>
>
>
=========================================================================
From: "Hugh R. Dean" <aspen@alphalink.com.au>
Subject: Re: [JN] 6146/6146B
Date: Sat, 5 Feb 2000 07:56:43 +1100
Source: Sound Digest Archive v02.n434
This tube is up for discussion:
>The same goes for the EL/PL519 line output tubes - inexpensive, very
rugged
> >and not at all bad sounding as triodes when used this way.
>
> Even better, they are in current production and they also feature the all
> important topcap connection (Paul really does like his Topcap's)....
A year ago I auditioned a de Paravicini SE stereo, integrated amp which used
this tube. Speakers were a Jericho horn with Fostex 208 sigma, and Denon
1015 CD player (average; not outstanding).
I, and two others, felt there was a strange metallic sheen on top of female
vocals. I'm curious to know if this was the PL519 or the amp design. (Tim
uses multi-path feedback, I understand, and this is famous for multiple
poles, which could explain it I guess.)
Any opinions?
Hugh R. Dean
Melbourne, Australia
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] 6146/6146B
Date: Sat, 05 Feb 2000 09:31:53 -0500
Source: Sound Digest Archive v02.n435
"P. de R. L." wrote:
> I know nothinks of the PL519.
>
> I just wanted to know if i could give the 6146 a good "bating" as a triode;
> sadly it seems not!
>
> Paul
Don't know why not, it is a very rugged tube, was very popular in Mil stuff so
there are lots of N.O.S..
An earlier post:
Hi
I never tried it as a triode but I have used it in a power amp some time
ago, also the early versions of the Ampeg SVT used it. It is a mobile
rated (mechanically rugged, very thick glass) Short wave frequency range
transmitter tube. Being made for Single Side Band operation, it is more
linear (I was told by a transmitter guy) than normal (AM) power tubes.
Do try its a neat tube, slightly less than a 6550/KT88 but more than its
conservative ratings suggest (and you got to love plate caps too).
Tom
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146/6146B
Date: Sat, 5 Feb 2000 21:18:32 -0000
Source: Sound Digest Archive v02.n435
Thanks, Thomas.
my point was that apparently I cannot run it at aproper voltage as a triode;
ergo no power.
Allen says "it burns". I presume he means "blow up".
However Daniel's mention of the 6239 is very interesting although I doubt
there are any in England!
Paul
- ----- Original Message -----
From: Thomas Danley <Tom@ppci.com>
To: P. de R. L. <triode@bow-tie.org.uk>
Cc: Hugh R. Dean <aspen@alphalink.com.au>; <Thorsten@tnt-audio.com>; Joenet
<sound@deliverator.io.com>
Sent: Saturday, February 05, 2000 2:31 PM
Subject: Re: [JN] 6146/6146B
>
>
> "P. de R. L." wrote:
>
> > I know nothinks of the PL519.
> >
> > I just wanted to know if i could give the 6146 a good "bating" as a
triode;
> > sadly it seems not!
> >
> > Paul
>
> Don't know why not, it is a very rugged tube, was very popular in Mil
stuff so
> there are lots of N.O.S..
> An earlier post:
> Hi
> I never tried it as a triode but I have used it in a power amp some time
> ago, also the early versions of the Ampeg SVT used it. It is a mobile
> rated (mechanically rugged, very thick glass) Short wave frequency range
> transmitter tube. Being made for Single Side Band operation, it is more
> linear (I was told by a transmitter guy) than normal (AM) power tubes.
> Do try its a neat tube, slightly less than a 6550/KT88 but more than its
> conservative ratings suggest (and you got to love plate caps too).
>
> Tom
>
>
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: [JN] 6146
Date: Mon, 7 Feb 2000 19:56:51 -0000
Source: Sound Digest Archive v02.n438
Rather than absorb the dreaded bandwidth with multiples, let me offer my
grateful thanks to all who have responded to my 6146 query.
I am much encouraged
thank you
Paul
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Sun, 06 Feb 2000 18:52:24 -0500
Source: Sound Digest Archive v02.n437
David Crittle wrote:
> Recent posts have mentioned the maximum screen (g2) rating of type 6146. At
> only 250 VDC, it is much lower than the maximum plate voltage, and hence is
> a limiting factor in designing a triode connected 6146 output stage.
>
> F. Langford-Smith (who complied the Radiotron Designer's Handbook) faced a
> similar dilemma in 1947 when he first saw the design for the Williamson
> Amplifier. D.T.N. Williamson's design used two KT66 in push-pull triode.
> Langford-Smith attempted construction using Australian-made 807 valves,
> presumably easier to obtain than KT66 in Australia in 1947. The
> plate/screen voltage of 400 volts was well above the rated screen voltage
> for type 807.
>
> Anyway, they went ahead and built it anyway with 807 valves. You can read
> the full report, including discussion of the screen grid rating, at this
> link:
>
> http://albums.photopoint.com/j/AlbumIndex?u=149682&a=1209111
>
> My point? Forget the 250 volts maximum rating. The 6146 looks like a pretty
> rugged valve, and I am sure they have survived and performed under all
> sorts of operating conditions.
>
> Or as we say in Australia: Suck it and see!
>
> ____________________________
> David Crittle
> retrovox@bigpond.com
> ____________________________
> Visit the Retrovox Where?house at http://www.users.bigpond.com/retrovox
> ____________________________
> Some pics at
> http://albums.photopoint.com/j/AlbumList?u=149682
Hi
>
I would agree totally, I have used this tube in "ultra linear" amp years ago
and the Ampeg SVT used 6 to put out 300W rms (although later they switched to
6550's). When replacing a 6550, they do need the bias increased (negatively)
to keep proper idle current, at least in my amp.
One thing that does not show in the ratings is that this tube is much more
mechanically rugged than say a sweep or other run of the mill power tube.
Being made for "Mobile" use, it has very thick glass and lots of internal
support and a plate structure that is large for a tube its size.
Also, I was told (by a very knowledgeable Ham) that this tube was made for
Single Side Band operation and had to be very linear (comparatively speaking)
in order to have low harmonic distortion. Being one of the last generation of
military power tubes, they are still very easy to find N.O.S. .
Try one, what the heck.
Tom Danley
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 00:30:46 -0000
Source: Sound Digest Archive v02.n437
Hello again David.
Perhaps you missed Allen Wright's comment? He said (appropos of running
6146 screens at what I call proper volts - 400 say); "They burn, brother,
they burn!"
Well, I have two nice new Brimars, and rather than burn them, perhaps either
I'll wait for 6293s or find some s/h 6146s and give them a bating! I'll
save the new ones for the guitar amp I have at the back of my head!
regards,
Paul
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 07 Feb 2000 08:53:30 -0500
Source: Sound Digest Archive v02.n437
David Crittle wrote:
> I should ask that old ham why he had 6L6 metal operating in a can of
> transformer oil
My grandfather told me about using a pair of 6550's in a transmitter generating
200W output, even more than a pair of 6146's. Sure, he said, the plates ran
red, but they were so cheap!
JL
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 10:39:49 +1100
Source: Sound Digest Archive v02.n437
Recent posts have mentioned the maximum screen (g2) rating of type 6146. At
only 250 VDC, it is much lower than the maximum plate voltage, and hence is
a limiting factor in designing a triode connected 6146 output stage.
F. Langford-Smith (who complied the Radiotron Designer's Handbook) faced a
similar dilemma in 1947 when he first saw the design for the Williamson
Amplifier. D.T.N. Williamson's design used two KT66 in push-pull triode.
Langford-Smith attempted construction using Australian-made 807 valves,
presumably easier to obtain than KT66 in Australia in 1947. The
plate/screen voltage of 400 volts was well above the rated screen voltage
for type 807.
Anyway, they went ahead and built it anyway with 807 valves. You can read
the full report, including discussion of the screen grid rating, at this
link:
http://albums.photopoint.com/j/AlbumIndex?u=149682&a=1209111
My point? Forget the 250 volts maximum rating. The 6146 looks like a pretty
rugged valve, and I am sure they have survived and performed under all
sorts of operating conditions.
Or as we say in Australia: Suck it and see!
____________________________
David Crittle
retrovox@bigpond.com
____________________________
Visit the Retrovox Where?house at http://www.users.bigpond.com/retrovox
____________________________
Some pics at
http://albums.photopoint.com/j/AlbumList?u=149682
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 11:37:02 +1100
Source: Sound Digest Archive v02.n437
>From: "P. de R. L." <triode@bow-tie.org.uk>
>Perhaps you missed Allen Wright's comment? He said (appropos of running
>6146 screens at what I call proper volts - 400 say); "They burn, brother,
>they burn!"
Is this comment from actual operating measurements or from intrepretation
of the figures in the handbook? Fender sure didn't check the rating of the
6V6GT when the Deluxe was designed! The higher plate voltages in a Fender
Deluxe can take out some 6V6 tubes, but certain brands have less trouble.
Check out the Radiotronics article, especially the second page at
http://albums.photopoint.com/j/ViewPhoto?u=149682&a=1209111&p=14753000
____________________________
David Crittle
retrovox@bigpond.com
____________________________
Visit the Retrovox Where?house at http://www.users.bigpond.com/retrovox
____________________________
Some pics at
http://albums.photopoint.com/j/AlbumList?u=149682
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 17:51:51 +1100
Source: Sound Digest Archive v02.n437
I re-read my last couple of posts, and I thought that perhaps my tone may
have seemed too 'rough and ready', dismissing published maximum ratings in
a few terse lines. Let me elaborate:
Paul has some 6146 valves he'd like to use triode strapped. I can remember
a few 6146 audio amps, like the Ampeg SVT bass amp, that use eight (or
six?) 6146 output tubes to yield 300 watts. An american magazine (Audio?)
published a construction article for what it called "The Musician's
Amplifer", using a pair of 6146 in a hefty monoblock. (I'm sure they didn't
call it a monoblock! To me, 'monoblock' sounds like a new product for the
construction industry.) These weren't triode connected, I can't recall ever
seeing a triode connected 6146.
Anyway, Paul wants to try 6146 as a triode. Perhaps hoping for more than a
few watts. But the book states 250 VDC maximum g2 voltage. Paul is probably
hoping to use a bit more than that, say 400 VDC. Using another
triode-strapped transmitting type tubes as a real example, I refered to
Langford-Smith's use of the 807 in 1947 at 400 volts triode connected: well
above the published maximum g2 rating of 300 volts. (see
http://albums.photopoint.com/j/ViewPhoto?u=149682&a=1209111 ) One assumes
it was a success; in subsequent issues of the Radiotron Valve Data Book,
the maximum ratings for triode connection of the 807 is 400 volts plate and
g2. Every other application listed has 300 volts as maximum g2 voltage.
Back to the 6146: even though the book says 250 volts maximum, why not try
it at 300 or even 400 volts triode connected? Maybe I'm wrong, and they
will go up in a puff of smoke! Maybe Allen W can elaborate on his burn baby
burn comment.....
I should ask that old ham why he had 6L6 metal operating in a can of
transformer oil
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 18:20:09 +1100
Source: Sound Digest Archive v02.n437
>Date: Sun, 06 Feb 2000 18:52:24 -0500
>From: Thomas Danley <Tom@ppci.com>
(to trim your beefy bandwidth, most snipped and this added)
>Try one, what the heck.
>
>Tom Danley
You know Tom, I think you're right!
Let's start the Society for the appreciation and propation of ''well i
just don't care about the lethal voltage exposed on the top cap anode (or
plate, call 'em what you want) just listen' !
There's tons of possibly great sounding NOS tubes (I have several tons
myself, and so do most of the big valve dealers on the planet) that have
never carried an audio note. These are tubes that have never been heard!
They might sound great! They are the 'oddballs', (I am one myself) that
can't just plug straight into a socket on your
Marantz/Fender/Quad/Marshall/Dyna whatever. Sometimes it's a simple thing,
like the top cap grid connection on type 6F8G. That stops most people using
it in place of type 6SN7. Sometimes it's a real pain, like getting a weird
socket and re-wiring your amp and adding a plate cap as well.
Understandably, most people don't want to modify their existing equipment.
I got some weird stuff that I'll never ever have time to use. It's not just
power valves or real old tubes with top caps. Anyone heard of ther CV5086?
It is a close cousin to the EF86, with a top cap: not real common on
miniature tubes. The civilian number is 6BS7. Specs seem identical to 6BR7
but for the top cap grid connection. See a pic at
http://albums.photopoint.com/j/View?u=149682&a=1102709&p=16111640
I'll get around to listed them sometime and add them to my webpage.
____________________________
David Crittle
retrovox@bigpond.com
____________________________
Visit the Retrovox Where?house at http://www.users.bigpond.com/retrovox
____________________________
Some pics at
http://albums.photopoint.com/j/AlbumList?u=149682
=========================================================================
From: David Barnett <davidbarnett@aristotle.net>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 07 Feb 2000 08:57:56 -0600
Source: Sound Digest Archive v02.n438
On Mon, 7 Feb 2000 17:51:51 +1100, David Crittle
<retrovox@bigpond.com> wrote:
> (I'm sure they didn't
>call it a monoblock! To me, 'monoblock' sounds like a new product for the
>construction industry.)
The word "monoblock" (or "monobloc") is a 1980s creation of the
British audio press. I would be happy to see it eliminated from the
audio lexicon once and for all.
- --dnb
=========================================================================
From: David Barnett <davidbarnett@aristotle.net>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 07 Feb 2000 08:57:57 -0600
Source: Sound Digest Archive v02.n438
On Mon, 7 Feb 2000 17:51:51 +1100, David Crittle
<retrovox@bigpond.com> wrote:
> I can remember
>a few 6146 audio amps, like the Ampeg SVT bass amp, that use eight (or
>six?) 6146 output tubes to yield 300 watts.
Six of 'em. And the early 6146-powered SVTs had a tendency to flame
out rather spectacularly. The 6550-powered ones are much more
reliable.
- --dnb
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 10:23:02 -0500
Source: Sound Digest Archive v02.n438
David asks:
>>>Back to the 6146: even though the book says 250 volts maximum, why not
try
it at 300 or even 400 volts triode connected? Maybe I'm wrong, and they
will go up in a puff of smoke! Maybe Allen W can elaborate on his burn baby
burn comment.....<<<
This was waaaaay back in my ham radio days at high school. The 6146 was
then ('circa '64) the new, trendy (and very expensive) option for the
output tube in a 100W SSB linear amp - I cheapo'd out with a vastly over
rated 807.
And yes 807's are hugely tough - like how about 1200V on the anode and
power dissapation such that the anode glowed bright red on each spoken
word!
But others who did use the 6146 said it was very sensitive to screen
voltage and the only safe way to ensure it lived was to regulate it. And
back then a regulator wasn't something you built up from a LM317 chip and a
couple of resistors.
The only audio amps I have come across using the 6146 were the monoblock
amps used for the three channel sound track Cinerama (movies) system - it
used +590 on the anodes but they regulated the screens at 200V!
Maybe "burn" was overstating it a little - "vastly reduced life with the
ever present risk of catastrophic failure" is perhaps closer.
My 1965 ARRL ham radio handbooks give the recommended screen voltage for
audio amp use at 200V. And in every circuit in that wonderful book that
uses the 6146, either for audio or RF (linear or Class C) service has the
screen regulated between 180 and 200V.
It is such a beautiful looking tube I hate to think people out there may be
torturing it to death.
Allen (VSE)
PS I did suggest a workable solution - wire them as triodes but just use
larger than usual screen to anode resistors - maybe start with something
like 4K7 and adjust accordingly. As I said, a friend has done this very
successfully with PL519 sweep tubes on 600V B+
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 07 Feb 2000 14:10:15 -0500
Source: Sound Digest Archive v02.n438
David Barnett wrote:
> On Mon, 7 Feb 2000 17:51:51 +1100, David Crittle
> <retrovox@bigpond.com> wrote:
>
> > I can remember
> >a few 6146 audio amps, like the Ampeg SVT bass amp, that use eight (or
> >six?) 6146 output tubes to yield 300 watts.
>
> Six of 'em. And the early 6146-powered SVTs had a tendency to flame
> out rather spectacularly. The 6550-powered ones are much more
> reliable.
>
> --dnb
Ahh yes, brings back memories of the smell of burnt resistors, bakelite and
wires.
Yep, the 6146 was only used for the first year and a half or so of
production with the 6550 being a better tube for the job.
While 100W /pr is a bit much, they are happy in the 60-80 watt / pr range,
like 60-80% of a 6550 (which can squeeze out over 100 W in "who cares about
distortion mode").
Of course anything with as much power supply as an SVT has will be
spectacular when it Zorches out. :-)
A nice thing about those days was Ampeg, Sunn and some others would supply
output transformers as service parts, all you had to do is sound "official"
and have a shipping address. Once they accepted an order the first time,
from then on you were on the books as an existing customer. This was very
different from McIntosh who I was totally unsuccessful in getting big op
transformers from, maybe they could tell I was a kid and not an authorized
dealer :-(.
The Sunn 2000 / 1200 series transformer was my favorite, I built a 10 or 12
of them, it put out an honest 200 Watts and had a good output trans, it
really went to 20 HZ at 200 W (and so was unusually large) but also went
high.
It used the basic Dynaco mkIII style pentode input triode phase splitter
and 4X6550's. and somebody on this or the bass list once said it was a
Dynaco design. I don't know how much a transformer like it would cost
today but back then it was $35.00, with everything coming from Fair Radio
and Newark.
Also back then, Radio Shack had there "Lifetime" guarantee on there gold
pin tubes. A few of the "help" there got to know me by name but the staff
turnover was high enough that I could go back as often as I could get a
ride with my little bag of tubes that had "mysteriously" failed or were
suspect (in my projects) and no questions asked. .
Unfortunately there power tubes didn't seem to hold up as well as RCA or GE
and it got to be too much of a pain having them fail
Memories ahh, well back to work
Best regards,
Tom Danley
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 19:36:45 -0000
Source: Sound Digest Archive v02.n438
Thanks for that.
> Maybe "burn" was overstating it a little - "vastly reduced life with the
> ever present risk of catastrophic failure" is perhaps closer.
But my amplifiers are like this anyway!
> >
> PS I did suggest a workable solution - wire them as triodes but just use
> larger than usual screen to anode resistors - maybe start with something
> like 4K7 and adjust accordingly. As I said, a friend has done this very
> successfully with PL519 sweep tubes on 600V B+
I saw this, thanks, but I wondered what the likely effect on the behaviour
would be. would it still be a "Triode"?
Paul
=========================================================================
From: "Michael B. Hathaway" <triode@t-three.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 19:00:00 -0800
Source: Sound Digest Archive v02.n439
This is partly true. All Sunns seem start with Dyna transformers - in fact
the original 100S/200S head actually had PAM1's and MKIII chassis inside the
tolex covered plywood box. Later on they started using locally produced
clones of the Dyna iron - Western Transformer Co. if I recall my repair days
correctly. The 1000S/2000S started with the MKVI transformer sets, as did
the first run of Model T's. Some even used the potted Dyna 440 iron - very
rare. The 1000S/2000S series ended up with MKVI clones, but the Model later
had Sunn designed iron in them. This isn't conjecture, but rather straight
from Conn Sundholm's mouth, the founder of Sunn.
Mike
- ----- Original Message -----
From: David Barnett <davidbarnett@aristotle.net>
To: <sound@lists.io.com>
Sent: Monday, February 07, 2000 6:34 PM
Subject: Re: [JN] 6146 screen voltage rating
> On Mon, 07 Feb 2000 14:10:15 -0500, Thomas Danley <Tom@ppci.com>
> wrote:
>
> >The Sunn 2000 / 1200 series transformer was my favorite, I built a 10 or
12
> >of them, it put out an honest 200 Watts and had a good output trans, it
> >really went to 20 HZ at 200 W (and so was unusually large) but also went
> >high.
> >It used the basic Dynaco mkIII style pentode input triode phase splitter
> >and 4X6550's. and somebody on this or the bass list once said it was a
> >Dynaco design. I don't know how much a transformer like it would cost
> >today but back then it was $35.00, with everything coming from Fair Radio
> >and Newark.
>
> I know that the 60W and 120W Sunns used Dyna output and power
> transformers (and the Dyna-sourced Cornell-Dubilier 4-section
> twist-lok 525V cap), so it wouldn't surprise me if this big one did
> too. The only Sunn tube amp I've seen that didn't have Dyna iron in
> it was the Model T, which was an el-stinko anyway. The 60W Sunns used
> the same set of transformers as the Dyna MkIII.
>
> --dnb
>
>
=========================================================================
From: David Barnett <davidbarnett@aristotle.net>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 07 Feb 2000 20:34:20 -0600
Source: Sound Digest Archive v02.n439
On Mon, 07 Feb 2000 14:10:15 -0500, Thomas Danley <Tom@ppci.com>
wrote:
>The Sunn 2000 / 1200 series transformer was my favorite, I built a 10 or 12
>of them, it put out an honest 200 Watts and had a good output trans, it
>really went to 20 HZ at 200 W (and so was unusually large) but also went
>high.
>It used the basic Dynaco mkIII style pentode input triode phase splitter
>and 4X6550's. and somebody on this or the bass list once said it was a
>Dynaco design. I don't know how much a transformer like it would cost
>today but back then it was $35.00, with everything coming from Fair Radio
>and Newark.
I know that the 60W and 120W Sunns used Dyna output and power
transformers (and the Dyna-sourced Cornell-Dubilier 4-section
twist-lok 525V cap), so it wouldn't surprise me if this big one did
too. The only Sunn tube amp I've seen that didn't have Dyna iron in
it was the Model T, which was an el-stinko anyway. The 60W Sunns used
the same set of transformers as the Dyna MkIII.
- --dnb
=========================================================================
From: Ross J Lahlum <rlahlum@juno.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Mon, 7 Feb 2000 22:43:15 -0600
Source: Sound Digest Archive v02.n439
David Crittle wrote:
>
> I should ask that old ham why he had 6L6 metal operating in a can of
> transformer oil
>
That was a trick to get more power out of the tube by letting the oil
help dissipate the heat.
Ever hear of the Heath "Can-tenna"? Similar concept - a 50 ohm resistor
immersed in a gallon paint can filled with mineral oil!
73,
Ross
________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re: [JN] 6146 screen voltage rating
Date: Tue, 8 Feb 2000 22:17:25 +1100
Source: Sound Digest Archive v02.n439
>From: "P. de R. L." <triode@bow-tie.org.uk>
>Perhaps you missed Allen Wright's comment? He said (appropos of running
>6146 screens at what I call proper volts - 400 say); "They burn, brother,
>they burn!"
I read his second post on this and he refers to pentode operation, not
triode connected
____________________________
David Crittle
retrovox@bigpond.com
http://www.users.bigpond.com/retrovox
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re; [JN] 6293/6146 & Screen Voltage in general
Date: Mon, 07 Feb 2000 10:11:21 -0800
Source: Sound Digest Archive v02.n438
Hi All,
F1rst, no, I have not done any experimentation with the 6293s, but David
Crittle has given some pretty good insight into what to expect from them
in audio use and it appears that they would be worth evaluating.
Secondly, with regard to whether a tube will operate satisfactorily at a
substantially higher-then-rated screen voltage, keep one thing in mind.
Tubes will tolerate higher screen voltges in triode than in pentode and
somewhere in between in UL. At very high plate current and
higher-than-normal screen voltage, the dynamic screen current could run
excessivly high in pentode operation. Very high plate current implies
lower plate voltage in normal operation, so in strapped-triode, at
higher plate current values, the screen voltage is driven low, thus
substantially reducing the dynamic screen current in comparison to what
would be encountered in pentode operation at very high screen voltage.
If you are a true tube experimenter, you surely must have an electronic
workbench with a suitable HV power supply for experimenting. If so,
make a quickie test circuit, something as simple as an octal relay
socket and a piece of plywood is fine. First, make the appropriate
connections to operate the tube with a millammeter in series with the
screen (which is connected to plate) and another in series with the
plate to monitor the plate current. We are assuming the application is
for triode-strapped operation. Then apply plate and bias voltage from
variable power supplies while monitoring the screen current. Increase
the plate voltage to the desired operating voltage while chasing the
bias to maintain the desired plate current, all the while monitoring the
screen current, noting whether the screen dissipation is exceeded. If
the desired plate voltage is reached with no screen dissipation
problems, connect an output transformer and drive the tube with a sine
wave at increasing signal levels up to full output while monitoring the
screen current and noting whether the screen dissipation is exceeded.
This could be done with a surplus PP opt and a pair of tubes, if no
suitable SE tranny is handy. I am assuming that triode plate curves are
not available, else there is no need for this exercise. Also, monitor
it to make sure it is not oscillating.
Once operational and it has been verified that the screen dissipation is
within limits, then experimentally determine the best load resistance,
then measure the distortion characteristics. If you have a spectrum
ananlyzer, the level of the third harmonic in PP operation is a good
indicator of the inherent linearity of the tube, thus is a reliable
indicator of its usefulness in audio applications.
One way to determinee the plate resistance would be by applying a small
ac signal to the grid(s) (with the tube(s) operating at the desired
plate voltage/current), measure the output voltage, then determine the
value of resistive load required for an output voltage of 1/2 the
unloaded value. This should be done at a low output voltage, say a
volt, to avoid over dissipating the tube(s). Then calculate the
equivalent primary resistance using N^2*Rl. If more convenient you
could apply the load directly to the plate(s). This will be plate
resistance for SE, or twice the plate resistance of a single tube for PP
operation. As a starting point you would then want to use a load
resistance somewhere around 3 times, give or take, the measured plate,
or plate-to-plate resistance as the plate load for that operating
voltage.
Next, measure the distortion at near clipping. If the third is in the
neighborhood of -50 dB, or better, at near full output, for a PP
circuit the tube should perform very well as a strapped-triode audio
output tube. KT66s in triode or 2A3/6B4Gs will do better than this,
depending on the load value, better for higher load resistance. At
least this is how I would approach the matter and the method I will use
when I do get around to evaluating the 6293s.
Dan Marshall
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re; [JN] 6293/6146 & Screen Voltage in general
Date: Tue, 8 Feb 2000 09:54:09 +1100
Source: Sound Digest Archive v02.n438
>Date: Mon, 07 Feb 2000 10:11:21 -0800
>From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
>
I am assuming that triode plate curves are
>not available, else there is no need for this exercise.
Triode specs for 6146 at
http://albums.photopoint.com/j/AlbumIndex?u=149682&a=1755425
I expect you will find that 6293 is very close in-spec to 6146.
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: [JN] Re: 6293
Date: Sun, 6 Feb 2000 21:46:34 -0000
Source: Sound Digest Archive v02.n436
Hello and thanks Kurt for this information.
It was Dan Marshall who kindly pointed me towards CK6293. He has some of
these and says they resemble 6146, but can take a higher G2 voltage.
It seems surprising that a valve that can cope with peaks of 3A can manage
only 10W Pa.
Do you have any more information on this curious valve - I'm always all a
quiver when I get the scent of something wacky! Any valve can make music;
that's what they were put on Earth for!
Paul
From: Kurt Steffensen <kurt-steffensen@teliamail.dk>
>
>
> "P. de R. L." wrote:. I've searched high and low for data on 6293.
>
> Hi Paul.
> It is a Tetrode Made for peak purpose.
> 6,3V/1,25A
> 10W
> 3-3,5 kV anode.
> Peaks up to 3A !
>
> Hardly suited for Audio , though ?
> Does not seems to be able to run class A or even AB2.
>
> - Kurt
>
>
>
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] Re: 6293
Date: Sun, 6 Feb 2000 23:51:22 -0000
Source: Sound Digest Archive v02.n437
> thanks, Kurt for your efforts.
I am surprised, because 6146 is rated at 25W Pa.
also, do you know the 12E1? this was some sort of PSU valve. This one can
take 800V on the anode and only 300 on G2. I do know that they have been
run at 400V as triodes; this was the reason I asked the original question
about 6146. However 12E1 has lovely triode curves and low ra (700
ohms/300V/100mA).
The only beam tetrode I have found so far that can take proper volts on its
beam plates is my dear friend the beloved 813 (VG2 max = 1.1kV) also Pa is
125W.
Have any other Joenetters got other suggestions for mad triode-strappers
(polite suggestions that is!).
Paul
Yes , it is surprising , but that is not that unusual for these special
> purpose pulse tubes.
> At 500 Volts g2 , no more that 7 Watts average anode dissipation are
allowed.
> I do think the 1,25 A filament is more weird. - Never mind , I got the
datas
> from Vade Mecum , - now I have consulted the
> But as you say , it is a wacky outsider , and after all , it just might be
the
> best tube ever on this planet....;-)
>
> - Sincerely Kurt... (Still laughing.......blink , blink ;-)
>
>
=========================================================================
From: Kurt Steffensen <kurt-steffensen@teliamail.dk>
Subject: Re: [JN] Re: 6293
Date: Mon, 07 Feb 2000 00:29:49 +0300
Source: Sound Digest Archive v02.n437
>"P. de R. L." wrote:
>It was Dan Marshall who kindly pointed me towards CK6293. He has some of
these and says they resemble 6146, but can >take a higher G2 voltage.
It does physical looks exactly like 6146 according to the drawing in the RCA
manual.- And it is a beam power tube.
(It is not really a tetrode as Vade Mecum suggest )
> It seems surprising that a valve that can cope with peaks of 3A can manage
> only 10W Pa.
Yes , it is surprising , but that is not that unusual for these special
purpose pulse tubes.
At 500 Volts g2 , no more that 7 Watts average anode dissipation are allowed.
I do think the 1,25 A filament is more weird. - Never mind , I got the datas
from Vade Mecum , - now I have consulted the
RCA transmitting manual.
It will take 3000 Volts anode Voltage ! (up to 5 kV PSU )
It is supposed to work as a pulse modulator tube. -According to the manual ,
it will do no good in any audio curcuit , that I can think of. (Unless you are
satiesfied with such a big 10 Watter ;-)
But it might behave different at 3-500 Volt anode , I do not know anything
about that . I have never seen the tube in real life.
Has Dan tested it ?
> Do you have any more information on this curious valve - I'm always all a
> quiver when I get the scent of something wacky! Any valve can make music;
> that's what they were put on Earth for!
Ha , ha... No , I am not sure I agree to that ;-)
To me it sure looks like a dead end. Even if it may run class A . 10 W , at
3-500 Volts , it is not at all supposed to , and the chance that it is lineare
, down here are small. I could think of many , many other 10 Watters , that
would be a lot more interesting.....
6146 or 807 , and this big family , is even quite good for audio , and will
take much more steady dissipation.
But as you say , it is a wacky outsider , and after all , it just might be the
best tube ever on this planet....;-)
- - Sincerely Kurt... (Still laughing.......blink , blink ;-)
=========================================================================
From: Kurt Steffensen <kurt-steffensen@teliamail.dk>
Subject: Re: [JN] Re: 6293
Date: Mon, 07 Feb 2000 03:59:30 +0300
Source: Sound Digest Archive v02.n437
"P. de R. L." wrote:
> > thanks, Kurt for your efforts.
>
> I am surprised, because 6146 is rated at 25W Pa.
Well , as I say , maybe it will permit more than 10 W at "low" Voltage.. ?
My guess is that the plate material or size , differs from 6146 ?
By studying the RCA manual , 6293 certainly does not look like a tube we would
choose for audio.
But it should not take that long to decide if you have a few at hand.
6146 makes a fine audio tube , though.
> also, do you know the 12E1?
Yup...Splendid tube :-)
> <snip<; this was the reason I asked the original question
> about 6146.
I see , - I am sorry , but I did not read that question of yours..
> The only beam tetrode I have found so far that can take proper volts on its
> beam plates is my dear friend the beloved 813 (VG2 max = 1.1kV) also Pa is
> 125W.
Excellent tube.......:- )
Buy it FAST. The price is going up :-(
> Have any other Joenetters got other suggestions for mad triode-strappers
> (polite suggestions that is!).
Check out 2E22 , please...
I haven't really experimented with this in triode mode , and I suggest that a
current limiting resistor is placed in the g2.
The max g2 Voltage , is however also low for this baby.
It is still relative cheep out there.
( The Neotrons are a quite better than the US- brands I have tested )
I wonder what a "polite suggestion" might be , BTW ? :-)
Now , we are talking about the 2E22.. Does any one have some curves for this ?
I would be happy to recieve a copy of these.
- - Kurt
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re: [JN] Re: 6293
Date: Mon, 7 Feb 2000 09:51:14 +1100
Source: Sound Digest Archive v02.n437
>It seems surprising that a valve that can cope with peaks of 3A can manage
>only 10W Pa.
The anode rating of 10 watts refers to use as a rectangular wave pulse
modulator with thousands of volts on the plate. In audio use it has similar
characteristics to 6146
____________________________
David Crittle
retrovox@bigpond.com
____________________________
Visit the Retrovox Where?house at http://www.users.bigpond.com/retrovox
____________________________
Some pics at
http://albums.photopoint.com/j/AlbumList?u=149682
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re: [JN] Re: 6293
Date: Mon, 7 Feb 2000 22:50:22 +1100
Source: Sound Digest Archive v02.n437
>Well , as I say , maybe it will permit more than 10 W at "low" Voltage.. ?
>My guess is that the plate material or size , differs from 6146 ?
>By studying the RCA manual , 6293 certainly does not look like a tube we would
>choose for audio.
>But it should not take that long to decide if you have a few at hand.
>6146 makes a fine audio tube , though.
I spoke with Brian Smith ( www.users.bigpond.com/brianswireless ) about
some 6293 tubes that I sold him a few years ago. He has since sold most of
them to customers requiring replacements for 6146B tubes. Radio Hams have
used them in Yaseau gear, and a pair is used in the driver stage of the
local AM transmitter in Rockhampton, North Queensland. So they seem quite a
suitable replacement for type 6146.
I managed to find specs for triode connection of type 6146, listed in my
Philips manual as type QE 05/40. The maximum rating in triode connection
is 400 volts. I've scanned the relevant pages and they may be viewed at
http://albums.photopoint.com/j/AlbumIndex?u=149682&a=1755425
____________________________
David Crittle
retrovox@bigpond.com
____________________________
Visit the Retrovox Where?house at http://www.users.bigpond.com/retrovox
____________________________
Some pics at
http://albums.photopoint.com/j/AlbumList?u=149682
=========================================================================
From: David Crittle <retrovox@bigpond.com>
Subject: Re: [JN] Re: 6293
Date: Tue, 15 Feb 2000 11:21:01 +1100
Source: Sound Digest Archive v02.n449
>Well , as I say , maybe it will permit more than 10 W at "low" Voltage.. ?
>My guess is that the plate material or size , differs from 6146 ?
>By studying the RCA manual , 6293 certainly does not look like a tube we would
>choose for audio.
>But it should not take that long to decide if you have a few at hand.
>6146 makes a fine audio tube , though.
Here's a pic of a 6293. The appearance to my untrained eye is identical to
6146B. That plate looks like it would take more than 10 watts!
http://albums.photopoint.com/j/View?u=149682&a=1102709&p=16406570
____________________________
David Crittle
retrovox@bigpond.com
http://www.users.bigpond.com/retrovox
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] Re: 6293
Date: Tue, 15 Feb 2000 18:57:09 -0000
Source: Sound Digest Archive v02.n450
My RCA transmitting tube manual is careful to say that the limit in ?square
wave modulation mode? is 10W
I think David is probably correct.
Paul
> Here's a pic of a 6293. The appearance to my untrained eye is identical to
> 6146B. That plate looks like it would take more than 10 watts!
>
>
=========================================================================
From: Tim_Bailey@medibank.com.au
Subject: Re: [JN] Re: 6293, the 12EI, and the 13EI etc.
Date: Tue, 8 Feb 2000 11:06:37 +1100
Source: Sound Digest Archive v02.n439
now don't flame.
I have two gurus, one has built two SE UL connected pentode amp with a 13EI!
Needs 70 volts rms drive.
ECC32, 6SL7 drivers cascaded. He is a follower of Langford Smith.
24 watts @ 0.5% thd, mostly second, 17% feedback. 3rd at 0.1%. With zero
feedback 5% thd.
Screen connected at 66% to the output transformer. He runs it at 70 watt plate
dissipation.
spec is 90 watts rated plate dissipation, plus the 20 watts from the filament.
Am borrowing them soon.
tim b
****************************************************************
NOTICE - This message is intended only for the use of the
addressee named above and may contain privileged and
confidential information. If you are not the intended recipient
of this message you are hereby notified that you must not
disseminate, copy or take any action based upon it. If you
received this message in error please notify Medibank
Private Ltd immediately. Any views expressed in this
message are those of the individual sender, except where
the sender specifically states them to be the views of
Medibank Private Ltd.
****************************************************************
=========================================================================
From: "P. de R. L." <triode@bow-tie.org.uk>
Subject: Re: [JN] Re: 6293, the 12EI, and the 13EI etc.
Date: Wed, 9 Feb 2000 23:40:11 -0000
Source: Sound Digest Archive v02.n441
STC spec says 60W max - good luck.
Paul
- ----- Original Message -----
From: <Tim_Bailey@medibank.com.au>
To: <sound@lists.io.com>
Sent: Tuesday, February 08, 2000 12:06 AM
Subject: Re: [JN] Re: 6293, the 12EI, and the 13EI etc.
>
>
> now don't flame.
>
> I have two gurus, one has built two SE UL connected pentode amp with a
13EI!
> Needs 70 volts rms drive.
> ECC32, 6SL7 drivers cascaded. He is a follower of Langford Smith.
>
> 24 watts @ 0.5% thd, mostly second, 17% feedback. 3rd at 0.1%. With zero
> feedback 5% thd.
>
> Screen connected at 66% to the output transformer. He runs it at 70 watt
plate
> dissipation.
>
> spec is 90 watts rated plate dissipation, plus the 20 watts from the
filament.
>
> Am borrowing them soon.
>
> tim b
>
>
>
>
> ****************************************************************
> NOTICE - This message is intended only for the use of the
> addressee named above and may contain privileged and
> confidential information. If you are not the intended recipient
> of this message you are hereby notified that you must not
> disseminate, copy or take any action based upon it. If you
> received this message in error please notify Medibank
> Private Ltd immediately. Any views expressed in this
> message are those of the individual sender, except where
> the sender specifically states them to be the views of
> Medibank Private Ltd.
> ****************************************************************
>
=========================================================================
From: Christian Rintelen <christian@rintelen.ch>
Subject: [JN] 6299 ceramic planar triodes
Date: Tue, 26 Jun 2001 17:38:13 +0200
Source: Sound Digest Archive v02.n916
We had a thread on ceramic planar triodes two weeks ago. In the
meantime I have scored some 6299 ceramic planar triodes, but I
don't have any data on them. Can anybody supply data sheets and
tell me where to connect what? The 6299 is made for coaxial use
but I don't know where the plate sits and where the heater
connects. And I definitely don't feel like frying the tubes with
200 V on the heaters.....
TIA, Đ
=========================================================================
From: "Kurt Steffensen" <kurt-steffensen@teliamail.dk>
Subject: Sv: [JN] 6299 ceramic planar triodes
Date: Fri, 29 Jun 2001 00:49:25 +0200
Source: Sound Digest Archive v02.n916
You can have a copy of my datasheets ( courtesy Phil Yeats :-) , at the Festival..
I am sure you can wait that long ( short ;-)
- - Kurt
> We had a thread on ceramic planar triodes two weeks ago. In the
> meantime I have scored some 6299 ceramic planar triodes, but I
> don't have any data on them. Can
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: [JN] 6336 A
Date: Sun, 28 Mar 1999 19:33:05 -0800
Source: Sound Digest Archive v02.n135
Hi Christian,
The 6336 has a 30 watt/plate dissipation rating vs. 13 watts for the
6080. There are other differences also.
Here is a convenient source for tube data for most tubes.
http://duncanamps.simplenet.com/tubedata/tubesearch.html
I have it bookmarked and refer to it often (as well as several speaker
databases). I spent some time recently reorganizing my bookmarks, as I
had so many I couldn't find anything. Organizing them in related
folders makes finding things a lot easier. This is also a convenient
means to organize and track ebay listings of interest, if you are an
ebay shopper. I go through the new audio listings on a daily basis and
bookmark items of interest, then organize them in time sequence adding
clarifying comments as req, plus the current bid price, reserve price,
etc. Then you can conveniently use this list to track the progress of
your items of consuming desire and to determine which items are ending
next, etc. A really neat way to waste a lot of time.
Dan Marshall
Christian Rintelen wrote:
>
> Joes,
> what's the max power per section of the 6336A when used as pass tube in
> a series regulated supply? I found some data on the 6080, but not on the
> 6336. (I was looking at Verdier's regulated supply in SP 13 and wondered
> if it wouldn't be more clever to replace the 6080s and the 100 ohm
> series resistors with 6336)
> Christian
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: [JN] 6336 A
Date: Thu, 29 Apr 1999 11:08:47 +0200
Source: Sound Digest Archive v02.n135
Joes,
what's the max power per section of the 6336A when used as pass tube in
a series regulated supply? I found some data on the 6080, but not on the
6336. (I was looking at Verdier's regulated supply in SP 13 and wondered
if it wouldn't be more clever to replace the 6080s and the 100 ohm
series resistors with 6336)
Christian
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: Re: [JN] 6336 A
Date: Thu, 29 Apr 1999 18:06:10 +0200
Source: Sound Digest Archive v02.n135
"Daniel J. Marshall" wrote:
> Hi Christian,
>
> The 6336 has a 30 watt/plate dissipation rating vs. 13 watts for the
> 6080. There are other differences also.
yeah, like a whopping 5 amps heater current... I was just wondering if one
could replace two 6080s with one 6336 in a regulated power supply a la
Verdier (Verdier uses four sections ie two 6080s).
BTW, thanks for the hint -- the tubesearch-URL has been in the "personal
toolbar folder" of my Netscape for months...
Christian
>
>
> Here is a convenient source for tube data for most tubes.
>
> http://duncanamps.simplenet.com/tubedata/tubesearch.html
>
>
> Christian Rintelen wrote:
> >
> > Joes,
> > what's the max power per section of the 6336A when used as pass tube in
> > a series regulated supply? I found some data on the 6080, but not on the
> > 6336. (I was looking at Verdier's regulated supply in SP 13 and wondered
> > if it wouldn't be more clever to replace the 6080s and the 100 ohm
> > series resistors with 6336)
> > Christian
=========================================================================
From: Joe Roberts <jroberts@io.com>
Subject: [JN] 6336 data
Date: Wed, 15 Sep 1999 10:41:13 +0000
Source: Sound Digest Archive v02.n278
Anybody got suggested operating points or plate curves for 6336? Anybody ever
build a PP amp with these suckers?
I've been getting interested in regulator tubes again. Should be able to put
together a wicked bass amp with 6336s.
Any info appreciated.
Joe
jroberts@io.com
=========================================================================
From: Tim Reese <tgrmail@nmr.MGH.harvard.EDU>
Subject: Re: [JN] 6336 data
Date: Wed, 15 Sep 1999 15:04:56 -0400 (EDT)
Source: Sound Digest Archive v02.n278
our Fearless Leader wrote
>Anybody got suggested operating points or plate curves for 6336? Anybody ever
>build a PP amp with these suckers?
The page from Vade Mecum is on Duncan's pages
http://duncanamps.simplenet.com/tubedata/pdf/vm308.pdf
and has curves for the 6336. Not quite sure how to read the table of static
characteristics at the top of the page...
I had a brief conversation with Dan Marshall about my pair of B-27 outputs
(1.5K Z) recently purchased from Mike L. He suggested using the 6336 as a
power tube, but I have not followed through yet. There's also a P-P (?) 600R
xfmr from Hammond currently being offered by AES - don't know any more about
it though, other than it has some use in Collins gear. Might be ok for
paralleled sections of a 6336 or even a 6080.
hth tr
- ----------------------------------------------------------------------
Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu
=========================================================================
From: Joseph Lowe <jlowe@cdc.net>
Subject: Re: [JN] 6336 data
Date: Wed, 15 Sep 1999 18:21:08 -0400 (EDT)
Source: Sound Digest Archive v02.n278
On Wed, 15 Sep 1999, Joe Roberts wrote:
> Anybody got suggested operating points or plate curves for 6336? Anybody ever
> build a PP amp with these suckers?
I built one about 12 years ago. As I remember I ran them at around 200V
and enough current to make the plates just red in a darkened room. I first
got interested in the 6336 because they were used in an old GE UHF
transmitter I used to maintain. They just look like they would work great
for audio, and they do. Anyway, the transmitter ran them red hot and after
about 6 months they would be totally black inside but they still were
good. These guys are tough...
The plate load was around 800 Ohms plate to plate. I found some
110-220 / 24VAC power transformers that worked real good. You don't need a
lot of inductance so I tested until I found some with good leakage
inductance.
The driver was 12AU7> 12AU7 phase splitter> 6BX7.
I used a LOT of capacitance in the power supply. Around 1000 mF as I
remember. A small amount of NFB (10db or so) was used to reduce distortion
and get better damping factor.
>
> I've been getting interested in regulator tubes again. Should be able to put
> together a wicked bass amp with 6336s.
You are correct, the bass from this amp was outstanding. Big, bold, totally
in control sound. The mids and high were so-so most likely from the less
than ideal output transformers. The thing gathered dust for a long time
after I got into SE, and I finally stripped it for the caps and tubes and
tossed the rest.
This amp was in a shootout at a high end store in downtown Philly in
the late 80's. It was up against the best Solid State stuff out there at
the time, and it held it's own even with the crappy output transformers.
Didn't drive Magneplaners very well though. :)
You will need well regulated adjustable bias for each section.
There is a LOT of variation tube to tube as well as section to section. If
you can find output transformers you will be well pleased with what the
6336 can do.
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 6336 data
Date: Thu, 16 Sep 1999 01:33:10 -0400
Source: Sound Digest Archive v02.n278
At 10:41 AM +0000 9/15/99, Joe Roberts wrote:
>Anybody got suggested operating points or plate curves for 6336? Anybody ever
>build a PP amp with these suckers?
>
>I've been getting interested in regulator tubes again. Should be able to put
>together a wicked bass amp with 6336s.
>
>Any info appreciated.
You can try about 270-300 Vp, -90 to -100 volts, about 80 mils (it was a
while ago) with a nice high load, like 5K p-p. Or 120mA, 200, about -60 to
- -70 with a lower load. Nice tube. Loves direct-coupled CF drive.
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: Sv: [JN] 6336 data
Date: Thu, 16 Sep 1999 12:24:13 +0300
Source: Sound Digest Archive v02.n278
Hi Joseph and Joe.
Anyway, the transmitter ran them red hot and after
>about 6 months they would be totally black inside but they still were
>good.
Ha,ha. Yes , this is actually true.
I once ran an amp. with a huge 6AS7G reg. PSU.
At one time I swapped the 6AS7īs with a single 6336.
It sounded remarcable better. (Tight and precise)
It smelled weird ,not burned , just that "hot glass smell" that high dissipation tubes
sometimes does , but after a week , I decided to lift the lid , to examine it.
It turned out that the 6336 , actually ran hot red. (Very hot)
It wasnīt dark red , but rather rosa. (pink?).
I was worried , but the 6336 was perfectly allright !
I then adjusted the Voltage , just enough to keep the 6336 away from the red area , and
in fact it sounded , even better here.(Not that it surprised me :-)
So though it might handle the dissipation well into the red point , I suggest anyone to stay away fr
om this area.
It will definately live longer this way.
As for the operating points for 6336 as a audio amplifier , I will try to dig as much as I can
from my weak memorie.
6AS7G and 6336 was the first triode amps I ever build.
First as PP , 6AS7G delivered 6-7 Watt A , and 6336 about 3 times more.
Both of them really did not care much about the load.
I ended up with 3500 Ohm , using both the 8 and 16 Ohm out , with 8 Ohm.
(1750 Ohm)
They both sounded best with high Voltage , but this is a dangerus area to hang these tubes in.
Sparks, and rattle , will confirm that , when you drive it to the limits !
(A diode from grid to Cathode is wise here)
Now, when I change my circuits to Single End , I was truly amazed with the quality.
We were used to ELīs , KTīs , and the US beam pentodes in PP-mode those days.
These 6AS7īs and 6336īs , were my first SE amps.
That experience changed my audio life forever.
I lended the 6336 SE amp. to Tommy Hørning and Peter Qutrop(Yes , that Peter) ,
they were both excited , and I have never seen it again , since that time :-)
This was way back in the 1980īs, and we all know what happent since.
Not that I was responsible for that , but I flatter myself , by beliving I did play a
minor posetive role in what later happened.
Such innocent belief is good to our health and selfrespect , whether it is true or not.
I then build 2A3īs,R120īs, 300Bīs etc. And for a while I was only into DHT in SE mode.
The 2A3 was certainly better than the 6AS7 , but the 6336 compared well , to many of the
famous DHTriodes.
Especially in the top , I found.
Thatīs allmost the opposite of what you found , Joseph , but I suspect that , these main trannies ,
is responsible for that.
So genuine Joe and fake Joes , if you Joe go for the 6336 Joe , go for the high
Voltage Joe.
BTW , genuine Joe , I still hold the $ 60,- for you , waiting for your reply.
- - Sincerely Joe Kurt
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: Sv: [JN] 6336 data
Date: Thu, 16 Sep 1999 08:07:49 -0700
Source: Sound Digest Archive v02.n279
Kurt Th. Steffensen wrote:
<snip>
> At one time I swapped the 6AS7īs with a single 6336.
> It sounded remarcable better. (Tight and precise)
<snip>
> It turned out that the 6336 , actually ran hot red. (Very hot)
> It wasnīt dark red , but rather rosa. (pink?).
<snip>
> So though it might handle the dissipation well into the
> red point , I suggest anyone to stay away from this area.
> It will definately live longer this way.
I collected several of these a while back because it looked as though
perhaps they would be suitable for an audio amp (and because they are
such a handsome tube), but never got around to implementing one, mainly
for lack of an appropriate SE opt xformer. In my investigation I
learned that tubes with graphite plates are properly run with the plate
in the red region. This is because they rely on the graphite plate for
gettering and for this to work properly they must be run red. I would
think that dull red would be more appropriate than bright red though. I
don't profess to be an expert in this area, so perhaps others could
enlighten us further.
>
> As for the operating points for 6336 as a audio amplifier ,
> I will try to dig as much as I can from my weak memorie.
> 6AS7G and 6336 was the first triode amps I ever build.
> First as PP , 6AS7G delivered 6-7 Watt A , and 6336 about
> 3 times more. Both of them really did not care much about
> the load. I ended up with 3500 Ohm , using both the 8 and
> 16 Ohm out , with 8 Ohm. (1750 Ohm). They both sounded best
> with high Voltage ,
That was my take from a casual perusal of the curves. They look to be
fairly linear at a higher voltage with a higher load impedance, i. e.,
high in comparison to their low, 200 ohm plate resistance, but quickly
get into their non-linear region with low-impedance loads.
> but this is a dangerus area to hang these tubes in. Sparks,
> and rattle , will confirm that , when you drive it to the
> limits! (A diode from grid to Cathode is wise here)
Interesting. I never got around to running one, but thought perhaps 300
volts, or more, might be about right, preferably more. They are rated
at 400 volts maximum plate voltage. What plate voltage did you find was
their maximum permissable value in audio amp service?
>
> Now, when I change my circuits to Single End , I was truly
> amazed with the quality. We were used to ELīs , KTīs , and
> the US beam pentodes in PP-mode those days. These 6AS7īs and
> 6336īs , were my first SE amps. That experience changed my
> audio life forever.
It would seem that a higher plate load and higher plate voltage would be
even more appropriate for SE operation. It would be interesting to
learn of the distortion spectra this tube generates. If a bias point
can be identified where it generates mainly 2nd order with low odd order
distortion products, perhaps it would sound quite nice. Man, I gotta
have a spectrum analyzer. When I was working in the electronics
industry I did quite a bit of bench work and used the trusty HP 141T
analyzer a lot. One sold on ebay a while back for $400 with plugins.
We paid upward of $10k for one new back then, actually $14k with the
tracking generator (a must have item). I have an unused 486 DX2-66
sitting about. Perhaps one of the analyzer plug-in cards would be the
way to go nowdays.
<snip>
Also, on another note, to achieve the sound of an SE amp with (strong
2nd order, low odd order distortion products), with the advantages of a
PP amp (high power, cheaper opt xformer, better damping, etc,) wouldn't
an acceptable approach be to design a very low distortion PP output
stage and optimize a SE driver stage (preferably transformer coupled)
such that the driver generates the 2nd order distortion products and
limits the maximum output power to where the output is never driven into
appreciable distortion? A low mu tube (mu=2) such as the 6336 with a
low rp (200 ohms) would perhaps be a good opt tube for this approach, if
it can be optimized to generate a very low amount of odd order
distortion products in PP.
Dan Marshall
> - Sincerely Joe Kurt
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: Re: Sv: [JN] 6336 data
Date: Thu, 16 Sep 1999 16:42:36 -0400
Source: Sound Digest Archive v02.n280
Hi All,
Another use for the 6336 is as an OTL output tube. Lux used them in
an amp I used to care for back in the late 70's - sounded rather nice...
Talking of OTLs - I built up an original NOS Futterman kit for a guy last
month - just one channel to get it running and give him sonmething to copy
for the other, sounded great and he has promised to bring them both back
when #2 is running.
Allen (VSE)
=========================================================================
From: Chris and Sue Beck <n9zes@execpc.com>
Subject: Re: Sv: Sv: [JN] 6336 data
Date: Thu, 16 Sep 1999 18:17:27 -0500
Source: Sound Digest Archive v02.n280
If you ever saw a Eimac 3-500Z at full dissipation, you'd see how bright the red is. It
truly is a "cherry red". Even the Svetlana SV572 series tubes run cherry red at the full
125W dissipation.
However, as you said, I would think the tube must be designed for that sort of use.
chris
"Kurt Th. Steffensen" wrote:
> In my investigation I
> >learned that tubes with graphite plates are properly run with the plate
> >in the red region. This is because they rely on the graphite plate for
> >gettering and for this to work properly they must be run red. I would
> >think that dull red would be more appropriate than bright red though.
>
> No , this is not the case.
> Whilest some of these might , fall in to this catogory , I do not know.
> But the graphite tubes I know , has warnings in the manufactors data-sheet ,
> that when driven beyond the max. data , the plates turn dull
> red (Weak rosa/pink).
> Graphite plates never turns bright red.
> (Well , it might if you run them at 200% or so )
>
=========================================================================
From: Joseph Lowe <jlowe@cdc.net>
Subject: Re: Sv: Sv: [JN] 6336 data
Date: Thu, 16 Sep 1999 21:14:10 -0400 (EDT)
Source: Sound Digest Archive v02.n280
On Thu, 16 Sep 1999, Chris and Sue Beck wrote:
> If you ever saw a Eimac 3-500Z at full dissipation, you'd see how bright
> the red is. It
> truly is a "cherry red". Even the Svetlana SV572 series tubes run cherry
>red at the full
> 125W dissipation.
>
> However, as you said, I would think the tube must be designed for that sort
>
>of use.
The Svetlana 572's use a titanium coating on the graphite plate as the
getter . They depend on high temp. to make the getter work.
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: Sv: Sv: [JN] 6336 data
Date: Fri, 17 Sep 1999 00:06:31 +0300
Source: Sound Digest Archive v02.n280
In my investigation I
>learned that tubes with graphite plates are properly run with the plate
>in the red region. This is because they rely on the graphite plate for
>gettering and for this to work properly they must be run red. I would
>think that dull red would be more appropriate than bright red though.
No , this is not the case.
Whilest some of these might , fall in to this catogory , I do not know.
But the graphite tubes I know , has warnings in the manufactors data-sheet ,
that when driven beyond the max. data , the plates turn dull
red (Weak rosa/pink).
Graphite plates never turns bright red.
(Well , it might if you run them at 200% or so )
>What plate voltage did you find was
>their maximum permissable value in audio amp service?
>>
I canīt remember exactly, but it was 300-350V.
400V was to close to the catastrophic points as an audio tube.
(Probably sounds better , though)
>Man, I gotta
>have a spectrum analyzer. When I was working in the electronics
>industry I did quite a bit of bench work and used the trusty HP 141T
>analyzer a lot. One sold on ebay a while back for $400 with plugins.
Yup , I used to have that 141 to.
Sold it , and regretted it ever since.
I would not mind pay $ 300,- for another one.
Any Joes got one for sale ?
>Also, on another note, to achieve the sound of an SE amp with (strong
>2nd order, low odd order distortion products), with the advantages of a
>PP amp (high power, cheaper opt xformer, better damping, etc,) wouldn't
>an acceptable approach be to design a very low distortion PP output
>stage and optimize a SE driver stage (preferably transformer coupled)
>such that the driver generates the 2nd order distortion products and
>limits the maximum output power to where the output is never driven into
>appreciable distortion?
Pheew. I read that 3 times , and still arenīt sure I understands it.
Maybe its because its late , and I am tired.
(Havenīt you ever heard of grammatic signs , Dan ? You know ; , . : etc :-)
A low mu tube (mu=2) such as the 6336 with a
>low rp (200 ohms) would perhaps be a good opt tube for this approach, if
>it can be optimized to generate a very low amount of odd order
>distortion products in PP.
Only one way to find out ;-)
The 6528 is rather interesting also , though the u is 9.
If you happen to run in to some 7241 or 7242 , well , these are serius low ri triodes !
- - Kurt
=========================================================================
From: Ken Gilbert <ride5000@ride.ri.net>
Subject: Sv: Sv: Sv: [JN] 6336 data
Date: Fri, 17 Sep 1999 11:27:30 -0400
Source: Sound Digest Archive v02.n280
>Now , I do know that the Svetlana series , is claimed to be supposed to
work in the
>red spot area.
>But I am rather sceptic about this.
>This is due to the circumstance , that when the plates turns hot enough to
be red glowing ,
>they also starts to relief the gas that the getters are supposed to absorb.
>Seems silly to me , to do it this way ?
But Kurt, you are not taking into account the composition of the plate
itself. Being graphite, it does not necessarily release any more gasses
when heated to such a high temperature. The titanium coating on the plate
is what provides the gettering action, according to the datasheets.
>Has anyone run a SV-811, 572 or 6550 in red glow for more than a year , or
two ?
>(Maybe their theory , works after all ??)
I am working on that part. I plan to light 'em up, if nothing else but for
the warm cheery glow that will radiate about the room. Also, winter is
coming.
The only thing I'm deciding is PP (good for 100W+ per channel) or SE
(25WPC).
Sometimes I like it rough, sometimes I like it delicate. It's hard to find
both in one place.
KG
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: Sv: Sv: Sv: [JN] 6336 data
Date: Fri, 17 Sep 1999 14:28:43 +0300
Source: Sound Digest Archive v02.n280
>On Thu, 16 Sep 1999, Chris and Sue Beck wrote:
>
>> If you ever saw a Eimac 3-500Z at full dissipation, you'd see how bright
>> the red is. It
>> truly is a "cherry red". Even the Svetlana SV572 series tubes run cherry
>>red at the full
>> 125W dissipation.
>>
>> However, as you said, I would think the tube must be designed for that sort
>>
>>of use.
>Joseph:
>The Svetlana 572's use a titanium coating on the graphite plate as the
>getter . They depend on high temp. to make the getter work.
>
No , I have never seen a 3-500Z at full rate. Sounds dangerus :-)
I did not knew these tubes were supposed to run bright red.
(I would love to see such animal in full duty , and HEAR it .......)
In fact I do not know much about these industry and special tubes.
But there is one thing , I would like to mention.
The max plate dissipation on many of these industry or class B/C , oscillator tubes ,
does not go for a class A set up.
As such they will only be able handle 20-70% of specified dissipation.
If pushed to max. anyway , the plate turn red as a sign of this.
The key is in fact the bulb temperature.
Now , I do know that the Svetlana series , is claimed to be supposed to work in the
red spot area.
But I am rather sceptic about this.
This is due to the circumstance , that when the plates turns hot enough to be red glowing ,
they also starts to relief the gas that the getters are supposed to absorb.
Seems silly to me , to do it this way ?
The good thing about these very hot filaments , are their capability to deliver massive sudden curre
nts.(Several amperes if nescassary)
But as they are high ri tubes , needing high transfomer ratio , this merit is of absolutely no use ,
in audio circuits.
(Unless perhaps , if we are talking about class B , Push Pull.)
Further the high temp. makes the tube more sensitive to "the piezo" effects , and the linear
transfere characteristica , we strawb so strong after , goes down , especially in dynamic situation
s.
I certainly carries the sad proof , that the SV-6550īs does not survives in this "red mode".
I have some 811īs , that are also supposed to have red plates , while working.
I never build an amplifier with them , as I was so dissapointed , with the behaveiur in the
test bench.
I remember that these also changed data , when run into the red area.
These SV-811īs , was never developed as class A , audio tubes.
I know Svetlane says so , but it is not true.
Such tubes , with this kind very high temp. filaments , are not suitable for high class A audio tube
s.
Especially , not when the assembly is made to high u conditions.
The 811 is a very old US design , it was originally developed for class B or C pulse service.
Regarding the 572īs , I have not had any of these in the test bench yet. It might be one hell of a a
udio tube , but it does suffer from the same high temp. filament construction ,
as the 811īs.
I suspect that these 572īs happened to be be an earlier Sovjet construction , that the sales folkīs
, considered to be possible to reintroduce as a class A , audio triode.
So my knowledge and experience with tubes glowing red at the plates , are all bad.
I know tubes such as 6336,211 and 845 , will withstand a certain overrate , and will survive , havin
g been glowing slightly red , for a given amount of time.
But it kind of takes the breath out of them , and the tube manuals , warns against it.
(I would never do it on purpose)
Has anyone run a SV-811, 572 or 6550 in red glow for more than a year , or two ?
(Maybe their theory , works after all ??)
- - Regards from the none glowing plate maniac.
=========================================================================
From: MHuber@t-online.de (Manfred Huber)
Subject: Re: Sv: Sv: Sv: [JN] 6336 data
Date: Fri, 17 Sep 1999 17:37:23 +0200
Source: Sound Digest Archive v02.n280
Kurt,
Simon Shilton of SJS Electroacustics once told me the following Story:
He had developed a SV572 amp and was showing it off at an audio fair.
It turned out that most of the the customers had prejudices against
the the red glowing plates. He eventually gave up on a good amp just for this
reason.
If you have a look into a RCA transmitting tube manual you will see that there
are many tubes that are supposed to operate with glowing plates while being
used in continuous commercial service (transmitters etc). These tubes are designed
to last for a long time. You donīt want your transmitter to go out of service
every few days!
>I certainly carries the sad proof , that the SV-6550īs does not survives in this "red mode".
The 6550 simply is not designed to operate under such conditions.
>These SV-811īs , was never developed as class A , audio tubes.
>I know Svetlane says so , but it is not true.
How do you know?
It may be true that the old american types 572B and 811A built the technological base on
which the SV-811 and SV-572 tubes where designed. This does not mean that they where not
designed for Audio. In fact, what else should they be designed for? What other application
exists these days for a linear direct heated low mu triode?
You may want to go the the Svetlana web site and have a look at the
data sheets. You will see that the SV811-3 and the SV572-3 are well suited for
SE class A circuits. If fact the curves of the SV572-3 are very close to the 845
>Such tubes , with this kind very high temp. filaments ,
>are not suitable for high class A audio tubes.
>Especially , not when the assembly is made to high u conditions.
High mu tubes tend to be less linear, this is why the SV-811 and SV-572 are
available in low mu variants.
>Has anyone run a SV-811, 572 or 6550 in red glow for more than a year , or two ?
I have no doubt that the SV811 and SV572 will have no problem while the 6550 may
die after a short time.
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 6336 data
Date: Thu, 16 Sep 1999 13:09:16 -0400
Source: Sound Digest Archive v02.n281
At 1:33 AM -0400 9/16/99, Grover Gardner wrote:
>At 10:41 AM +0000 9/15/99, Joe Roberts wrote:
>>Anybody got suggested operating points or plate curves for 6336? Anybody ever
>>build a PP amp with these suckers?
>>
>>I've been getting interested in regulator tubes again. Should be able to put
>>together a wicked bass amp with 6336s.
>>
>>Any info appreciated.
>
>You can try about 270-300 Vp, -90 to -100 volts, about 80 mils (it was a
>while ago) with a nice high load, like 5K p-p. Or 120mA, 200, about -60 to
>-70 with a lower load. Nice tube. Loves direct-coupled CF drive.
>Grover Gardner
>groverg@postoffice.att.net
Oops, I should have mentioned--the operating points I speak of apply to the
Cetrons--they tend to bias higher than other brands. They also will take
such high plate voltages better than other types. My understanding is that
the metal-plate varieties don't hold up as well as the graphite ones.
Kurt is right, IMHO, that this tube sounds good at high plate voltages--as
unfeasible as this seems, looking at the curves.
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: Sv: [JN] 6336 data
Date: Thu, 16 Sep 1999 13:14:16 -0400
Source: Sound Digest Archive v02.n281
>Interesting. I never got around to running one, but thought perhaps 300
>volts, or more, might be about right, preferably more. They are rated
>at 400 volts maximum plate voltage. What plate voltage did you find was
>their maximum permissable value in audio amp service?
I have it on very good advice not to exceed 300 Vp. They will take 400,
but not for long :-) (as in extended use). Also Cetrons are most
available, sweetest sounding and best able to withstand this kind of work.
Dull red plates are not a problem, in my experience. Avoid metal plates.
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: Sv: Sv: Sv: [JN] 6336 data
Date: Fri, 17 Sep 1999 11:24:00 -0400
Source: Sound Digest Archive v02.n281
"Kurt Th. Steffensen" wrote:
> The max plate dissipation on many of these industry or class B/C , oscillator tubes ,
> does not go for a class A set up.
> As such they will only be able handle 20-70% of specified dissipation.
> If pushed to max. anyway , the plate turn red as a sign of this.
> The key is in fact the bulb temperature.
I don't mean to pick on you here, Kurt, but don't any of you people own and read tube manuals or dat
a sheets? Otherwise, you're just guessing when you hypothesize that plate color is
a bad thing, which it may not be.
For example, the RCA Transmitting Tubes clearly states the difference between continuous duty (CCS)
and intermittent duty (ICAS), where applicable, for their high power tubes. It also
clearly states the plate color (if any) at rated dissipation.
Of course, you can run your plates at any color you want, just like you can run your single plate 2A
3's at 30W dissipation. Far be it from me to stop you.
Joe Lowe, where are you?
JL
=========================================================================
From: SBench@aol.com
Subject: Re: Sv: Sv: Sv: [JN] 6336 data
Date: Fri, 17 Sep 1999 22:42:33 EDT
Source: Sound Digest Archive v02.n281
In a message dated 99-09-17 08:35:22 EDT, kurt-steffensen@teliamail.dk writes:
<<
These SV-811īs , was never developed as class A , audio tubes.
I know Svetlane says so , but it is not true.
Such tubes , with this kind very high temp. filaments , are not suitable for
high class A audio tubes.
Especially , not when the assembly is made to high u conditions.
The 811 is a very old US design , it was originally developed for class B or
C pulse service. >>
Hi Kurt,
Note that there is a BIG difference in construction of SV811A and SV-811-3
or SV811-10. The 811A is a hi mu, and you rightly point out it ain't worth
**** for class A. The SV-811-3/10 have a *much* wider grid spiral so the
effective mu is way lower, and effective rp is thus much lower. These
beasties will work quite well in class A. (and are even reasonably linear).
If I were doing it, I'd have called these things something else besides
811s, cause they are *not* 811's in the traditional sense. The high filament
rating helps in the sense that since they can and do provide high
current (and lower voltage than the 811A) operation, the current does not
cause saturation, making A2 operation feasible [if you're into A2
operation].
Best Regards,
Steve
=========================================================================
From: John Levreault <jlevro@mediaone.net>
Subject: Re: Sv: Sv: Sv: [JN] 6336 data
Date: Sat, 18 Sep 1999 09:56:54 -0400
Source: Sound Digest Archive v02.n281
SBench@aol.com wrote:
> Note that there is a BIG difference in construction of SV811A and SV-811-3
> or SV811-10. The 811A is a hi mu, and you rightly point out it ain't worth
> **** for class A.
[The late?] Nobu Shishido would have disagreed.
JL
=========================================================================
From: SBench@aol.com
Subject: Re: Sv: Sv: Sv: [JN] 6336 data
Date: Sat, 18 Sep 1999 12:11:33 EDT
Source: Sound Digest Archive v02.n281
In a message dated 99-09-18 09:59:21 EDT, jlevro@mediaone.net writes:
<< Bench@aol.com wrote:
> Note that there is a BIG difference in construction of SV811A and SV-811-3
> or SV811-10. The 811A is a hi mu, and you rightly point out it ain't worth
> **** for class A.
[The late?] Nobu Shishido would have disagreed.
JL
>>
Hi,
I guess there's room for everyones tastes. If you run the 811 or 811A
at 1250 to 1500 volts you can indeed get a couple of watts in Class A1.
You'll also hear paper-on-the-piano-strings if you listen for it. I'm
very sensitive to that particular distortion. I'm also probably in the
minority view here.
In A2, with DC filaments, that tube works pretty well, though. With
AC filaments, theres a modulation effect going thru 0 bias that's
above the threshold of audibility.
Wonderful that so many people can come to relatively divergent
views on a single topic. In the end *you* have to judge what *you*
like.
Best Regards,
Steve
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: re: [JN] 6336 data
Date: Sat, 18 Sep 1999 15:38:52 +0300
Source: Sound Digest Archive v02.n281
Dear John,Ken, Chris and Manfred.
John:
>I don't mean to pick on you here, Kurt, but don't any of you people own and read tube >manuals or d
ata sheets? Otherwise, you're just guessing when you hypothesize that plate >color is a bad thing, w
hich it may not be.
Donīt worry , John , you arenīt picking on me.
Yes, I read the manuals.
I should have explained myself better. Sorry , for that.
I will try better this time.
>For example, the RCA Transmitting Tubes clearly states the difference between continuous duty (CCS)
and intermittent duty (ICAS), where applicable, for their high power tubes. It also
>clearly states the plate color (if any) at rated dissipation.
Yes , that was also my point.
The frequency , pulse rate and bulb temp. is what finally decides the max. dissipation of a
thoriated tungsten filament type.
(Holding the plate material out of the picture )
>Of course, you can run your plates at any color you want, just like you can run your single >plate
2A3's at 30W dissipation. Far be it from me to stop you.
I think , you misunderstands me ?
I am warning against the red area.
(Or is it me , that misunderstands you :-) ?
Manfred:
>He had developed a SV572 amp and was showing it off at an audio fair.
>It turned out that most of the the customers had prejudices against
>the the red glowing plates.
Well , I must admit , that you can count me in that prejudices crowd.
This is only because , I never experienced any tube to be good , or to live long , when
the plates glow red. (Or any other color)
Perhaps , such tubes exists , but I have not tried such yet.
All materials in the old tubes (Thats pre 1955 or so ) , releases gas , when the temperature
gets high. (Glass,micas, metals etc)
The purpose of the getter is to absorb these gasses.
If the gasses is not absorbed , it will eventually lead to failures.
It often starts with the grid drawing current. This particually error , finally leads to thermal
runaway.
So the argument of driving the tube at excessive high temperature , in order to have the
getter working , seems like driving fast in a car , in order to have the brakes working , in my opon
ion :-)
Maybe the Svetlana tubes , has something particually unique to them , that I do not know about.
But those of the Svetlana that I have had on the test bench , did exactly , what all other tubes I k
now of does , when driving glowing red.
They started to draw more and more current. (SV-811 and 6550 )
The best of the 811īs , was the low u one. (u 3 ).
This is also what goes for all the western tubes , I know of.
These are less pronounced to grid current and other nasties.
(I look foreward to actually build an amplifier with the SV 811-3)
Offcourse , I know that a 6550 is not supposed to run red either , but it did , long before
max. specified plate dissipation were reached , and the first feedback , I got from the Svetlana ass
ociates , was that these particually 6550Cīs , was supposed to do this !
I did not really belived them , though.
>If you have a look into a RCA transmitting tube manual you will see that there
>are many tubes that are supposed to operate with glowing plates while being
>used in continuous commercial service (transmitters etc).
Perhaps , you have read other RCA manuals , than I , but none of the ones I have ever
read , recommends the glowing red area.
In the contrary , they warn , that they will glow slightly , or not at all , when the max. dissipati
on , are reached.
Now , we need to get more precise , in the contend of what is meant by glowing plates.
Most , power tubes with thoriated tungsten filaments , glow the plates , when operated.
(Some oxide types does also.)
This can be examined by watching them ,in
total darkness.Sometimes it is nescassary to disconnecting the filament.
When the filament light is out , we usually have just enough time to watch the plates still
glowing.
But it is not this condition , I am talking about.Neither is it this the tube manuals are refering t
o.
I am discussing the glow that can be seen without problems , in normal light conditions.
The RCA transmitting tube manuals warns about the barely notable color that indicates , that the max
imum dissipation are reached.
This was a practical way in the old days , to see when the max. were reached.
Many technicians used this methode , with weak light , to adjust the transmitting tubes.
That is why some tubes wears the warning , that max. dissipation is reached BEFORE the
plates , starts to glow !
>The 6550 simply is not designed to operate under such conditions.
No , that is also my claim.
>>These SV-811īs , was never developed as class A , audio tubes.
>>I know Svetlane says so , but it is not true.
>How do you know?
>It may be true that the old american types 572B and 811A built the technological base on
>which the SV-811 and SV-572 tubes where designed. This does not mean that they >where not
>designed for Audio. In fact, what else should they be designed for? What other >application
>exists these days for a linear direct heated low mu triode?
Yes, they are claimed for audio purpose now.
Originally they were developed for class B and C service.
The only thing , changed , as far as I can see , is the u , of some of them.
The original ones from the west was: 811,812,DA 41 and DA 42.
The low u 811īs and 572 is very suitable for audio.
But as I see it , if they were build as oxide filaments , glowing at lower temp. , the would
realy be able to dissipate these specified Watts , with out having to glow red.
If these 811īs and 572īs , indeed does live as long as 211īs,845īs , 300Bīs etc . at max.
dissipation , and does not act weird in this situation ,I have no problem with them glowing
bright red , or whatever.
>You may want to go the the Svetlana web site and have a look at the
>data sheets. You will see that the SV811-3 and the SV572-3 are well suited for
>SE class A circuits. If fact the curves of the SV572-3 are very close to the 845
Yes, I have the data-sheets. I also have the early ones they released.
These curves did not even show the Voltage for the high dissipating class A area.
I wonder why not ?
As I say , some of the low u 811īs and 572īs might sound good , and is certainly well ,
worth considering. I will build amps. with these.Definately.
But:
At the test bench , they do not look promising in the max. claimed power dissipation.
A friend of mine , that is well into tubes , has made several amplifiers with both of these
tubes , yet he preferes the 845 , in every respect.
He is usually right.
( that is no proof , I know , but to me it is very reliable )
>>Has anyone run a SV-811, 572 or 6550 in red glow for more than a year , or two ?
>I have no doubt that the SV811 and SV572 will have no problem while the 6550 may
>die after a short time.
You may be right , but untill that is proven , I will doubt it very much.
Ken:
>But Kurt, you are not taking into account the composition of the plate
>itself. Being graphite, it does not necessarily release any more gasses
>when heated to such a high temperature. The titanium coating on the plate
>is what provides the gettering action, according to the datasheets.
Well , everything releases gas , when the temperature gets high enough.
Some metals used in tubes release most gas when heated close to melting.
This is usually done in hydrogene athmosphaere.
Exept titanium !
It is amoung very few "metals" , that is possible to empty fully for gas.
And even better , it is an excellent getter material.
Titanium is actualy used to absorb certain gasses at living room temperature !
Now, titanium absorbes different gasses best at certain temperatures.
These are low , compared to other getters.
If the SV tubes needs the titanium to be so hot that the plates glow red , in order to absorb gas ,
it must be a rather bad designed tube. I can hardly belive this to be so.
The ceramics does not release any substantial gas , if proper treated , and the gas from the hard gl
as , can be absorbed by the titanium , at the filament temp. it self.
Neither the graphite , nor the glass (Even hard borosilicate ) likes high temperature.
Besides from excessive gas release , the graphite and the glass gets stressed , and they
both creepes.
I now remembers , that the 811 in fact uses some micas also !
Thats a silly way to design a hot running class A tube.
The way I (prefere ) read the SV data-sheets , they allows the plates to get red ,
but they do not recommend it ?
>>Has anyone run a SV-811, 572 or 6550 in red glow for more than a year , or
two ?
>>(Maybe their theory , works after all ??)
>I am working on that part. I plan to light 'em up, if nothing else