Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

Upgrading output transformers
Upgrading output transformers
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
Thread Tools Search this Thread
Old 18th December 2008, 03:47 PM   #11
richwalters is offline richwalters
diyAudio Member
richwalters's Avatar
Join Date: Sep 2003
Location: Schwartzwald
Tigro; enclosed are some early loop gain graphs: The upper Majestic is far more consistent. Both examples sampled over modest powers.
Note, as the transformer size goes up, so do the parasitics which effect the upper bandwidth far more than with lower power examples and relies on nfb to correct response. As mentioned regarding snubbers; a 10KHz square wave pushed through at 100W ++ will easily destroy 3W rated stuff, so components must be rated accordingly. Hint: The driver stage must not slew before the output stage and class A balanced drivers will sink min 30mA per pair.
Hope this helps

Attached Images
File Type: jpg 8659_mag perf.jpg (70.8 KB, 332 views)
  Reply With Quote
Old 4th January 2009, 01:18 AM   #12
tigro is offline tigro  Romania
diyAudio Member
Join Date: May 2006
Dear Rich

Thank you for your detailed and well documented answer.
I use an existing design, it's an Antique Sound Lab AQ 1008DT
monoblock and I want to upgrade the output transformer.
I will use Sowter U059 model and have it modified for 2.25K
primary impedance insrtead of 1.75K.


  Reply With Quote
Old 4th January 2009, 09:12 AM   #13
cypher is offline cypher  Poland
diyAudio Member
Join Date: Mar 2007
Location: Gdynia, Poland
Originally posted by kevinkr
...ASL HK makes very reasonable quality OPTs .....
Do you know website where I can check models and prices, thanks ?
  Reply With Quote
Old 4th January 2009, 03:09 PM   #14
kevinkr is offline kevinkr  United States
diyAudio Moderator
kevinkr's Avatar
Join Date: Sep 2004
Location: Boston, Massachusetts
Upgrading output transformers
Here is the Antique Sound Lab site, I no longer see any transformers listed there since the redesign so you will need to email them and find out if they still sell a line of transformers. (As I've indicated they used to make some good ones, they wind all of the transformers and chokes used in their products and used to offer a selection at retail as well.)


The odd choice of text and background colors make their site a very difficult read on my computer.
"To argue with a person who has renounced the use of reason is like administering medicine to the dead." - Thomas Paine
  Reply With Quote
Old 5th January 2009, 05:45 AM   #15
richwalters is offline richwalters
diyAudio Member
richwalters's Avatar
Join Date: Sep 2003
Location: Schwartzwald
I agree. Lack of imagination. Easier and more exact reading my 1950's slide rule.

  Reply With Quote


Upgrading output transformersHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Pointers on upgrading CDP output stage. S.Spielbergo Digital Source 23 21st July 2015 09:47 AM
Difference between SE output transformer and push-pull output transformers hilbert_mostert Tubes / Valves 12 8th March 2009 05:10 PM
Help identifying a pair of output transformers and power transformers mjk130 Parts 3 30th January 2009 10:44 AM
upgrading to bal. output trannys redrabbit Solid State 7 1st January 2006 08:42 AM
SE Output Transformers DVDHack Tubes / Valves 32 19th January 2004 10:52 AM

New To Site? Need Help?

All times are GMT. The time now is 05:13 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio