Crown IC 150 Preamp popping noise - source of problem?

[jimkarl]

I thought I woudl take a different approach to solving this. Since we can't figure out why C12 isn't filtering DC properly, I thought may we should figure out why it getting so much voltage in the first place, so i took some measurements (see pic). The first value is the problem left channel, second value is the now working right channel. If there is only one value, it is the same on both channels. You can see there is roughly 3 volts floating around on the left channel where there is not on on the right. Q1 was in a socket so I pulled and tested - tested good no leaks. Q2 was soldered in, but I pulled and tested too, again, tested good no leaks. R56 and R19 slightly out of tolerance so I pulled and replaced. R12 measures fine so left in place. C12/R20 of course were replaced previously. The only other item I suspected was C10 that 27pf cap. I pulled but not sure my meter reads correctly that low. Seeing about 70pf, but then again, my meter shows some 30+pf with no leads connected to anything, so I'm not trusting any readings there. i don't have a replacement to test with. Does it make sense that if C10 was bad that could be the cause of the 3 volts there? Or possibly C15 that 8.8nf cap? Or Q2 really is bad even though tested good? (Since Q1 was socketed I swapped channels - no change) I don't see any other avenues for that "extra" voltage to get created.

crown150-phono board voltages.jpg