12B4A tube amplifier with output transformers - 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 9th December 2003, 11:36 AM   #1
diyAudio Member
 
Join Date: Nov 2002
Default 12B4A tube amplifier with output transformers

Hi

I have looked thru the forum trying to find a PP 12B4A amplifier that uses output transformers. NO, I do not want the transformerless version that has been floating on the web.

Please post any interesting ideas as I have heard the 12B4A is a distant cousin of the 2A3 tube.

Thanks
Joe
  Reply With Quote
Old 9th December 2003, 12:31 PM   #2
Fuling is offline Fuling  Sweden
diyAudio Member
 
Join Date: Aug 2001
Location: Sweden (Mora)
12B4A, my favourite pet!!

Unfortunately Ive never tried them in a PP amp but Im sure theyll perform fine. Give them nice transformers and driver stages, they deserve it

And by the way, be sure to mount them with the cathodes visible, since they glow quite nice.
  Reply With Quote
Old 9th December 2003, 01:44 PM   #3
diyAudio Member
 
Brett's Avatar
 
Join Date: Jan 2002
Default Re: 12B4A tube amplifier with output transformers

Quote:
Originally posted by burnedfingers
I have looked thru the forum trying to find a PP 12B4A amplifier that uses output transformers.
I've never seen one

Quote:
Please post any interesting ideas as I have heard the 12B4A is a distant cousin of the 2A3 tube.
OTTOMH idea
OPT = 10ka-a
B+ = 200V
Ia = 28mA/tube
Rk = 420R // 100uF common to both tubes
Vg = - 21.5V

Driver is a diff or paraphase ECC99 with Hammond 156C as loads at 150Va and 15mA/tube.

PSUD a decent power supply.
  Reply With Quote
Old 11th December 2003, 10:46 AM   #4
316a is offline 316a  England
diyAudio Member
 
316a's Avatar
 
Join Date: Dec 2002
Location: West London
Default Re: Re: 12B4A tube amplifier with output transformers

Quote:
Originally posted by Brett


I've never seen one



OTTOMH idea
OPT = 10ka-a
B+ = 200V
Ia = 28mA/tube
Rk = 420R // 100uF common to both tubes
Vg = - 21.5V

Driver is a diff or paraphase ECC99 with Hammond 156C as loads at 150Va and 15mA/tube.

PSUD a decent power supply.
Op point looks good . I would use a 30VA 115+115/6+6 mains toroid as an output , secondaries paralleled to get a prototype going . 12B4a vary electrically , better to buy a bunch and match them up for PP , better still add variable grid bias and balance meters . A reference could be this schematic which uses a similar valve (beefier version:6CK4)

http://tinpan.fortunecity.com/saints...er/6ck4-pp.gif

Hope this helps

316a
  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
Tube amp transformers 4 pwr 4 output 1 choke (used) Westerp Swap Meet 0 18th May 2009 07:37 PM
Tube Output Transformers in NY pedroraiser Swap Meet 3 9th September 2008 02:09 AM
amplifier for unknown output transformers? tonskulus Tubes / Valves 20 9th December 2007 11:36 AM
Best price for tube output and power transformers ? mario2005 Tubes / Valves 1 31st July 2006 07:12 AM
New output transformers for Quicksilver amplifier Original Burnedfingers Tubes / Valves 13 20th February 2003 09:32 PM


New To Site? Need Help?

All times are GMT. The time now is 12:11 AM.


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