Silvertone 1464 solid state 100 amp

[Leo_Gnardo]

Anything else I should consider?

This right here:

with the exception of the expensive power supply ones.

ANY old amp, a prime trouble spot is filter caps. Bet you half a peach swapping in new ones will diminish your hum to acceptable levels.

[freegan72]

Early on I removed everything from the bridge rectifier out and used a lab DC power supply for the +26 V and -26 V. I left the filter caps in initially. I just removed them--nothing changed.

[freegan72]

Thanks for the reply

[olddawg]

I hope this adventure works for you and you are doing it for the learning experience.. but I wouldn’t be heartbroken if you aren’t successful. Unless something has changed these amps aren’t very valuable, functional, or even usable.

[freegan72]

It's just for fun/challenge. I have no delusions that I am going to get anything out of it beyond that.

[52 Bill]

Other than suggesting that you start a new thread for your problem, you have already isolated the problem to the preamp (everything before Q5).

Continue to isolate the preamp sections to try and find the problem.

[olddawg]

Other than suggesting that you start a new thread for your problem, you have already isolated the problem to the preamp (everything before Q5).

Continue to isolate the preamp sections to try and find the problem.

Or swap in a bag of electrolytic caps starting with the filter caps...

[The Dude]

Conveniently, the schematic has transistor voltages. I'd start by measuring those and see if anything is off.