Transformerless tube designs

[kpeek]

I am looking for information, schematics, etc. in applying discrete opamp circuits in lieu of transformers in tube circuits. Similar to M*lleniaM*dia, S*mmit, P*ndulm, and others.

I would like to use a passive EQ with a selectable SS/12au7 gain stage and then into a verymoo compressor- either a 6ES8 or 6BC8 or possiby 5670.

I am unsure about the driver stage- may borrow from the Verymoo, Sta-level or even the 436C for simplicity.

The use of 990 style opamps for input/output is where I become fuzzy.

The input should be simple.

The output is a bit more difficult. I would like to employ a DC servo type output but I am unsure about getting the driver stage to integrate with this type of output.

Can anyone educate me on this subject?

I have read Bruce Rosenbilt's book on OTL's but he doesn't address using opamp's to balance/unbalance his transformerless circuits.

 

[Gus]

Go to the sticky meta meta. read all the threads on eqs and compressors take some notes.

Then ask again with smaller more defined questions.

You are asking for alot of information, some has been addressed here.

Other things to read would be any of the Walt Jung books for opamp circuits, problems, how to use etc. Ap notes at the IC companys web pages. The Art of Electronics, old tube books