There's a Conrad-Johnson "diggers" website that Jordan went on and pulled up what appears to be close to the correct schematic. Unfortunately, the literature appears to be about the MV75, no suffix, and there are significant differences between the machine we have in for repair and the schematic we downloaded.

Channel 1 is about 6dB down, following replacement of an open 20 ohm cathode resistor for one of the 6550A's. Output transformers appear to be okay -- and symmetrical -- that is, using a signal generator they have the same "gain" primary-to-secondary and vice versa.

Ideally, we would like a schematic and board layout for the MV75A-1variant of this model.

Thanks in advance!!

Fred

Fred,
I'm guessing this one is the one you have already?

That's the one Fred and I have already.

On the model we have, there is MAJOR additional filtering in the negative bias supply. Plus (don't you always hate this?) some "amateur brain surgeon" has been in there, and it's hard to tell what's "stock" and what's not.

Fred