I bought a Supreme Fidelity Amp., The amp had apparently failed, and was given to someone to fix, they clipped a few wires, and never fixed it, there is no schematic in it. They did not mark anything. The tube lineup is as follows. (5Z3)(6A6)(6A6)(6B5)(6B5)(75)

Model PX5 / Serial 887. The company, out of New York City, is apparently now absorbed by Bogen. I would appreciate any other Info, or places I could look. My local public Libraries were no help. I had plans to try it out as an instrument amp, either guitar, bass,vocal. I don't' have the microphone that went with it, that was sold separately, so I guess I need to know what kind of load is required for inputs and outputs. It has two Gain Dials a Tone Dial, and two switches, I'm assuming one for Power and one for Standby, as only one is marked On/Off. I took it to a repair shop and the guy said he couldn't do anything with it. It would cost more than it's worth.etc.

I checked Riders, Riders PA and Sams; it isn't listed there.

Hope you didn't pay too much. Yes, they were acquired by David Bogen, but I was never able to find any documentation on the thing (I found one in a salvage bin in 1966). At the time, all of the old-timers I talked to said that they were contract-built for the military, were barely good for a low-power PA amplifier, and were famous for trashing power transformers. I eventually got mine running, but true to form, the transformer failed about a year later. It never sounded very good--pretty high distortion. A high Z crystal mike (50Kohms or better) drove the mic channel. A 3.5V crystal cartridge of similar impedance worked for the phono (second) channel. The second toggle switch on mine selected which input was active, but it showed signs of being rewired. Good luck!

Post some high-res photos here and we can probably help you figure it out