2A3 Sovtek characteristics - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 10th July 2005, 06:10 PM   #1
diyAudio Member
 
teodorom's Avatar
 
Join Date: Apr 2004
Location: Milano
Default 2A3 Sovtek characteristics

Hi all,
is there anybody having relaible characteristics of the 2A3 Sowtek ? New Sensor, when asked, did'nt answer and I'unable to to find those data anywhere.
Thanks
__________________
Teodoro
  Reply With Quote
Old 10th July 2005, 08:07 PM   #2
diyAudio Member
 
Join Date: Nov 2002
Location: North Herts, UK
Try Sovtek 2A3 & 6550 anode curves

James
  Reply With Quote
Old 10th July 2005, 08:16 PM   #3
diyAudio Member
 
teodorom's Avatar
 
Join Date: Apr 2004
Location: Milano
Default Thank you ..

James, I already knew those curves, and, using them, I have "built", using SPICE, my PP amplifier. My problem is that I don't know the maximum plate voltage, current, power and so on ...
Everyone says that they are quite a 300B, but I cannot find anywhere anything supporting this statement.
Thanks again
__________________
Teodoro
  Reply With Quote
Old 10th July 2005, 09:24 PM   #4
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
FWIW JC says that the Sovtek 2A3 cathode is just a 2A3 cathode - so running at 300B currents is not a good idea. Overvoltage is a different issue. Sovtek seem very reluctant to recommend any kind of abuse which is probably understandable. I have run mine at 27-28W over extended periods of time (years) with no ill effects.
  Reply With Quote
Old 10th July 2005, 09:34 PM   #5
diyAudio Member
 
teodorom's Avatar
 
Join Date: Apr 2004
Location: Milano
Default Load Lines

So, my question is: a Sovtek 2A3 "living" on these Load Lines, will die ?
Attached Images
File Type: gif load lines.gif (21.3 KB, 685 views)
__________________
Teodoro
  Reply With Quote
Old 10th July 2005, 09:37 PM   #6
diyAudio Member
 
teodorom's Avatar
 
Join Date: Apr 2004
Location: Milano
Default Details ...

Vak=325V, Vgk=-66.2V, Ia=24.9mA, W=8,1W (at idle)
__________________
Teodoro
  Reply With Quote
Old 11th July 2005, 05:58 AM   #7
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: USA
> a Sovtek 2A3 "living" on these Load Lines, will die ?

It should not.

RCA 1937 says 300V maximum "Design Center". This includes allowance for utility power and other variation. In the 1950s, RCA re-rated tubes as "Design Maximum", which must not be exceeded. The "Maximum" ratings were usually 10%-20% higher than the "Center" ratings. So your 325V "should" be OK, but don't go much higher.

Your dissipation curves are low on average, but cross the original 15 Watt rating. We rarely did this in the old days. However, speech/music should not be a problem this way. The time spent around 200V 100mA 20 Watts is too short to cook the plate. And analog_sa says much higher average dissipation is possible on the Sovtek 2A3s.

But consider this. Dropping plate voltage to 300V gives a very safe operating point, with only about 1dB less power. Will you notice 1dB less power?
  Reply With Quote
Old 11th July 2005, 01:31 PM   #8
diyAudio Member
 
Join Date: Nov 2002
Location: North Herts, UK
Just to support the above, my son has run Sovtek 2A3s at 325Vak, Ia=60mA for 3 years without problems. Only 20Watts Pa but nice high voltage.
  Reply With Quote
Old 11th July 2005, 10:56 PM   #9
diyAudio Member
 
Join Date: Nov 2003
Location: NY
FWIW,

I have been running sovtek 6B4G's at ~350V a-k, and a good 75mA current.

Theses things are robust. They've been running like this for over 2yrs. I would consider 30W as the max plate dissipation. I think the cathode does output a bit more current than vintage 2A3's, but its not at the level of a 300B.

A hell of a nice current production tube. Half the price of russian 300B's, too.

share and enjoy
  Reply With Quote
Old 12th July 2005, 01:27 AM   #10
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Quote:
RCA 1937 says 300V maximum "Design Center".
Type numbers these days bear little relationship to traditional performance specs for these tubes. It's something that bothers me deeply- a "572B" or "2A3" or "300B" is more of a brand than anything resembling a uniform performance spec. I've got some Svetlana 572B on hand that come in three mus- 3, 10, and 30. None of which correspond to the "official" mu of type 572B. And the pinout is different, too, just to add insult to injury.

So it seems to be with 2A3- what you and I think of as "2A3" is not generally what is sold (except as NOS) as 2A3, other than the accident of a filament cathode and more-or-less three active elements.

edit: Comparing curves shown in the Sovtek link to GE 6550A curves shows that "6550" is apparently a brand now, too.
__________________
And while they may not be as strong as apes, don't lock eyes with 'em, don't do it. Puts 'em on edge. They might go into berzerker mode; come at you like a whirling dervish, all fists and elbows.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
PL 519 electrical characteristics Seraph Tubes / Valves 16 7th September 2011 08:41 AM
Sovtek 6B4-G Lowrider Tubes / Valves 11 25th February 2009 12:43 PM
Plate characteristics rossdt Tubes / Valves 8 7th August 2006 07:03 PM
FS: 2A3 Sovtek NickC Swap Meet 0 17th October 2004 01:52 AM
Tweeter Characteristics tbright Multi-Way 4 22nd September 2004 03:45 PM


New To Site? Need Help?

All times are GMT. The time now is 05:55 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2