As the subject says, I have a 112R with some
problems. Specifically, it has a blown speaker
(this seems to be common, I think) and it shows
about 44VDC on the output terminals. Try as I
might, I just can't seem to locate a faulty component. Both power transistors seem fine, as do all other transistors. I'm guessing that this 4558 in the circuit is some type of servo to used to minimize DC offset, but I can't tell for sure. Any suggestions?