What To Do - 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 24th March 2006, 05:18 PM   #1
jwatts is offline jwatts  United States
diyAudio Member
 
Join Date: Jan 2004
Location: Erwin, Tennessee
Default What To Do

I was at the dump last Saturday and managed to find an old reel to reel for a whopping five bucks. This thing has a monstrous 600 volt transformer in it and a 5Y3GT rectifier tube and it appears to work fine. So I gutted it and now I have a really nice transformer and the components to build a nice power supply. I have a four 7591 power tubes lying around along with several 12AX7ís plenty of caps, resistors, a nice metal chassis. I donít however have a set of output transformers with the required impedance to build a push pull amp with the 7591ís. Does anybody have any thoughts on what I could do with those parts? I really donít have the cash to shell out for the transformers for a push pull amp.
  Reply With Quote
Old 24th March 2006, 05:38 PM   #2
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Put the parts carefully away until such a time as you can buy some decent output transformers. They won't vaporize in the meantime.
__________________
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
Old 24th March 2006, 05:41 PM   #3
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
Consider SEPP and then you can use salvaged mains toroidals for outputs. Sounds good to.

Shoog
  Reply With Quote
Old 24th March 2006, 05:49 PM   #4
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
A quick calculation suggests that SEPP might just work. 300V over each tube uses your 600V. Needs a 3K load which a 230:12V transformer would supply and would be easy to source. You would get about 10W of class A, or a bit more with a 50% UL design using the 110V primary winding.
This is basically the power amp I have at the moment, but with 807's.

Shoog
  Reply With Quote
Old 24th March 2006, 06:25 PM   #5
jwatts is offline jwatts  United States
diyAudio Member
 
Join Date: Jan 2004
Location: Erwin, Tennessee
Default SEPP

The transformer CT is 300V. SEPP meaning (Single End Push Pull). My knowledge level on tube design is intermediate. Are there any schematics on the internet concerning this design?
  Reply With Quote
Old 24th March 2006, 06:46 PM   #6
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
You can derive 600V DC from a 300V AC centre tap so that would be OK.
There are designs for SEPP amps on the web. There is one for an EL36 and one for an EL34 which come to mind. Do a Google search and see if you like what you find. Unfortunately you would have to learn enough to actually design the output stage yourself. This isn't so difficult when you grasp the basic principle.

Shoog
  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



New To Site? Need Help?

All times are GMT. The time now is 11:54 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