Working on an old school mtx amp. "turns on, fries subs".
Put it on the bench and replaced the output capacitors and all of the op amps, the VCA, and the opto couplers while I installed IC sockets.
Everything looked good sitting idle so i brought it out to test, sure enough it fried a sub sitting idle.
Its seems something on the +/- 15V power supply is pulling way too much current.
Eventually R178 and R177 burned- looks to be for current limiting the positive and negative power supplies.
I have power at each inductor yet so im just looking for what could be puling so much current.
anybody have any insight on the input circuitry on this bad boy?
Put it on the bench and replaced the output capacitors and all of the op amps, the VCA, and the opto couplers while I installed IC sockets.
Everything looked good sitting idle so i brought it out to test, sure enough it fried a sub sitting idle.
Its seems something on the +/- 15V power supply is pulling way too much current.
Eventually R178 and R177 burned- looks to be for current limiting the positive and negative power supplies.
I have power at each inductor yet so im just looking for what could be puling so much current.
anybody have any insight on the input circuitry on this bad boy?