Comments on: Altec 436 Compressor: Taming the Output Level

By: A Michael Fox

A Michael Fox — Wed, 07 Dec 2016 20:24:45 +0000

Hello: I am building a 436 clone from the attached diagram. I figured with your experience you could explain one thing: There are two stepped switches at the bottom of schematic from the 6AL5 back to the input stage. I understand input gain, output gain and ratio, but what to these other switches do ? Can they be potentiometers as well ? Thanks !!

http://i1110.photobucket.com/albums/h448/DBPendrill/436ControlAmp.jpg

By: Chris

Chris — Mon, 26 Sep 2016 03:09:20 +0000

Could you tell me please the utc transformers you used?

By: Etienne

Etienne — Fri, 29 Jan 2016 00:06:25 +0000

Hello!

I was wondering if you could help me on how is working the Altec 436c.

My specific question is:

how big is the gain made by the 6bc8 tubes ? I calculated approximately 20-25 (no units) . But it wouldn’t make sens beacause the 6cg7 tubes are biased with -3V at the cathodes.

How i am seing this is: if I put 1V peak sin wave as an input, it gets amplified by 25 first and then goes to the push-pull stage. but if the cathode are at -3V the input signal of the push-pull stage will easily be more than 3v (in this example it would be 1×25=25V)

And I know I’m not supposed to insert signals larger than the cathode bias.

What am I getting wrong?

Thank you very much for your help! It would be a lot appreciated.

Cordially,

Étienne

By: chris

chris — Wed, 04 Dec 2013 23:05:45 +0000

In reply to Christopher Dion. I don't have an original. but i've serviced them. it should be fairly flat 40-15K. if its not, it needs servicing.

By: Christopher Dion

Christopher Dion — Wed, 04 Dec 2013 23:00:58 +0000

Hello, I have an Altec 436C. I found it nice in some ways, but almost unusable. I wanted to know, is the frequency response quite flat on yours ? Because on mine it isn’t at all.

Chris