Beta Bass Rescue

[george]

I just picked up (rescued) a BB from Craig's list. The amp will needs some TLC since it is not functional. Though it "powers up" the red and green LEDs don't light up and there is only a loud hum at the output. I assume that either the +-15V supply is gone or the wonderful CMOS logic needs to be replaced. Can anyone point me to replacement pots for the tone/level controls? Just assuming that the Moto CMOS devices are unobtainium as well? How often do these devices fail  - ESD??? Hope it's the power supply

THX

[loudthud]

On the Beta Lead I bought it was the +15 reg that died. Everything looked normal except no sound. All the CMOS logic (except the chips in the signal path) and LED's run off the -15 so look there. The two regulator transistors run hotter than I'd like. Still debating if I should try clip on heat sinks or something on the chassis. The CMOS chips can still be found, just type the numbers into a search engine and you'll get several hits for people selling them.

[george]

Thanks for the reply. I'll check out the TIP29/30's in the morning. Any chance that you know where to source the pots for this amp? The level pot on one of the channels had the plastic shaft sheared off.

THX