freestompboxes.org

Howdy!
I like the look of the Urei Mod One discrete opamp. It uses 5 BJT transistors.
My question is how do I adapt this circuit to germanium BJT transistors? Got a bunch of Soviet ones and would like to use them! I am trying to learn the math behind it, so I'd like to learn why/how it works or doesn't work.
Can I reverse engineer from silicon BJTs? (Essentially the opposite of this: http://www.hawestv.com/transistorize/germanium1.htm)
Thanks for your help in advance!

Old thread, but did not come across it earlier, interesting though

That is a very simple opamp, even more limited than the Melcor 1731, interesting!

You could try to start by keeping everything the same, but substitute than lonesome PNP in the middle with a germanium transistor.
The output stage probably doesn't do that much, but after substituting the middle BJT, maybe do the input pair by flipping it between the rails.

http://sureshotstudio.blogspot.com/2011 ... opamp.html
https://groupdiy.com/threads/urei-op-amp.16313/