75v is full rail and shouldn't be there if the signal from the generator is swinging above AND below ground. The voltage I'd expect on the output may not be a near perfect 0.000v but it shouldn't be more than a fraction of a volt at 50% duty cycle swinging both above and below ground.
The signal you're feeding into it is similar to a carrier wave. I'm trying to divide the circuit to see if I can see a problem.
The signal you're feeding into it is similar to a carrier wave. I'm trying to divide the circuit to see if I can see a problem.
A few days ago I did get this amp functioning correctly. I have it all back together with all new power supply fets and drive resistors. How tight do you clamp down the transistors to the chassis? Just snug then by feel for the most part like any other transistors? The amplifiers I regularly
repair dont have a aluminum clamp like this amp does.
repair dont have a aluminum clamp like this amp does.
What was ultimately the final problem?
Use your best judgement.
Hopefully you found the lead-in threads when threading the screws in.
Use your best judgement in tightening, remembering that you're screwing into soft aluminum.
Use your best judgement.
Hopefully you found the lead-in threads when threading the screws in.
Use your best judgement in tightening, remembering that you're screwing into soft aluminum.
I simply replaced the octocouplers and the amp powered up and functioned like it should. No more whining from the power supply. I didnt test it running full output yet but should be able too pretty soon. I realized all the silpads they used had paste and or some kind of glue (maybe to hold them in place during manufacturing). I didnt use any paste as I used the pink bergquist I cut to size for them. I did notice the original silpad in there was quite thick. The stuff I used was a little thinner but think it should be ok.