Welcome to Solid State Guitar Amp Forum | DIY Guitar Amplifiers. Please login or sign up.

September 30, 2022, 07:44:44 PM

Login with username, password and session length

Recent Posts


100W ACDelco SS with Interstage Transformers, winding info included!

Started by matthias, January 04, 2015, 01:44:16 PM

Previous topic - Next topic


Looking around for information on Interstage Transformers I found this.
Figured I'd share it here...

J M Fahey

Thanks for posting  :dbtu:

This was a killer, grounbreaking design, the first high power, real 100W RMS amp to be published.

Most important is that both power transformer and the usually mystery driver one detailed winding data are included, and both use standard, available materials.

Mind you: DTG110B are germanium, circuit as is provides 0.22V bias.

It can be easily modded for Silicon and the 2N3055H version has been very popular here in Argentina for the last 45 years, go figure.

Yes, they are still being built today  :o
Very simple, very robust, specially if using a pair of modern MJ1502x or MJ2119x

Very easy to repair too; since there is no DC coupling because driver transformer separates power transistors from the rest of the amp, usually you just replace both output transistors and burnt resistors (a 10 minute job) and they start again.

Very popular in faraway provinces and small towns for that reason.


 Thank you for posting this.

This is somewhat similar to Professor Bereskin's solid state amp as included in the designs on Pete Millett's site. There was a somewhat similar FET version posted by a DIY designer in the UK as I recall.