BSS DPR-402 repair
hello all, after reading these forums for some time I decided to register to ask for help on this specific matter, I have this BSS DPR-402 which has already been serviced three times and after little use it starts showing the same problem.
I have the schematics and I wonder if anyone can give me a clue to find and solve the issue. the unit has noisy ("scratchy") outputs and it shows signal on both the output meters.
I have been told something about the output being shorted when using the unit with unbalanced cables, so the output op-amp gets fried and the output is noisy.
I understand how the output can be shorted: since the BSS is pin3 hot, when using with single TRS insert console, the + gets shorted to ground.
BUT my unit has had the XLR wires swapped for "normal" polarity, PLUS my console has separate send/return jacks PLUS I always repatch the unit with power button switched off.
so where to look? my best guess is that some other component around the output op-amp is failing too and this leads to the chip that fries.
any help is appreciated, I have full schematics and a multimeter. I maybe could grab an oscilloscope if needed.
PS: I have another identical DPR-402 which is working fine but has a broken power switch (it does not latch anymore)... any source for the part? it is extremely difficult to get BSS parts here in Italy even through the distributor.
I can't make it less loud, sorry, the house master fader just broke