Re: Denon AVR-1912

Very, very carefully, of course.

Can you get to the rectifiers easily? I imagine they will be close to the main transformer and filter caps. Maybe one lead on them is marked with a + or -. Measure to the metal chassis, if you can't find the center tap of the transformer.

Another way is to be extremely careful and measure the voltage on each transistor lead. The transistor with positive voltage should have one lead that measures what the rated supply voltage is supposed to be, say + 50 volts or so. The other transistor, connected...

Re: Denon AVR-1912

The pop is DC offset. Does it do this on all channels?

The offset occurs, for some yet unknown reason, because the conduction of the faulty channel(s) output transistors is not the same- one is powered from the positive supply and the other from the negative supply, and when all is well, in a perfect world, the conduction cancels to yield 0 volts DC offset. That unequal conduction can be from an offset voltage applied to the output stage from a previous stage, the transistors themselves, unequal power supply voltages (maybe), or something like that....