Power Transfomer For Valve Amp Question - 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 13th April 2011, 04:34 PM   #1
diyAudio Member
 
Join Date: Apr 2011
Default Power Transfomer For Valve Amp Question

Hey,

I got a 'Mains Transformer' for a Valve amp project I am working on from ebay, but I have little knowledge of testing mains transformers and was wondering if any of you can make sense of this Power Transformer for me

Click the image to open in full size.

The writing on it is:
0 120 0 120
ANGLIA A53882
35 0 35

Apparently this transformer came from a 100w valve Sound city amp.
I need the outputs for this amp: Marshall JMP 2204

I was planning on making the 50w version as I have little money for all the valves and this is just a project of mine


Many Thanks!
  Reply With Quote
Old 13th April 2011, 04:59 PM   #2
diyAudio Member
 
hidnplayr's Avatar
 
Join Date: Sep 2008
It looks like yur transformer has 2x35V secondaries, wich would be very likely if it came out of an amp with transistor outputs!
You cant use this transformer for a tube output stage.
__________________
Real tubes have top-caps
  Reply With Quote
Old 13th April 2011, 05:04 PM   #3
diyAudio Member
 
Join Date: Apr 2011
Ah... That's pretty annoying to be honest! He advertised it as a tube output transformer

Oh well, Thanks for the quick reply!

Does anyone know how to test the outputs anyway? - I may use it for something else... Also to see if it actually works!
  Reply With Quote
Old 13th April 2011, 05:29 PM   #4
DF96 is online now DF96  England
diyAudio Member
 
Join Date: May 2007
This looks like a mains transformer, not an output transformer. Unclear to me whether the 0-120 windings are primaries or secondaries. Does it have any other windings?
  Reply With Quote
Old 13th April 2011, 05:33 PM   #5
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Primaries. Series to work on 240, paralleled for 120.
__________________
The more you pay for it, the less inclined you are to doubt it.- George Smiley
  Reply With Quote
Old 13th April 2011, 05:34 PM   #6
DF96 is online now DF96  England
diyAudio Member
 
Join Date: May 2007
Probably, but there could be a primary hidden on the other side?
  Reply With Quote
Old 13th April 2011, 05:35 PM   #7
diyAudio Member
 
Join Date: Apr 2011
Yea, Dont think I said it was an output transformer, Sorry if I did!
I got slightly confused as the post by hidnplayr says about the 'output stage' But still...
Thats the only writing on the entire Transformer... I just need it for the Power Transformer in the Schematic.

I thought The power Transformer was meant to output a few hundred volts, something like 400... So I need to test it if the writing doesnt tell me what it outputs. I was a bit afraid to just wack 240 volts straight through it though!
  Reply With Quote
Old 13th April 2011, 05:49 PM   #8
diyAudio Member
 
Join Date: Apr 2011
Theres no other pins on the transformer as well... just the 8 pins on one side with all the writing.
  Reply With Quote
Old 13th April 2011, 05:51 PM   #9
diyAudio Member
 
Rundmaus's Avatar
 
Join Date: Aug 2005
Hi there,

no need for testing, the writing tells very clearly what will come out:

If you put in 120V (primaries parallel) or 240V (primaries in series) it will put out 70V center-tapped on the secondaries.

I think there's not much use for 70V in tube audio, except for a negative bias supply perhaps...

Greetings,
Andreas
  Reply With Quote
Old 13th April 2011, 06:04 PM   #10
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
Quote:
You cant use this transformer for a tube output stage.

Not necessarily. The available 70 VAC could be voltage multiplied by the type of circuitry shown here. Five stages should get the rail into KT88/6550 "territory". That 35-0-35 is quite adequate for powering a 100 W. "sand" amp. and should support 50 tube W. easily enough. BIG 'lytics are needed in the multiplier.
__________________
Eli D.
  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
dunb-noob transfomer question sturmj Parts 8 15th October 2010 03:31 PM
Simple SE power transfomer question? ryc989 Tubelab 29 3rd May 2010 07:29 PM
another transfomer question AltecDarpa Power Supplies 1 2nd April 2010 07:10 PM
Proposed Transfomer/Valve Layout BL21DE3 Tubes / Valves 5 23rd May 2004 10:44 PM
Super isolated power transfomer for pre-amp. Brian Guralnick Solid State 3 21st April 2003 06:23 AM


New To Site? Need Help?

All times are GMT. The time now is 09:45 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