Hi, I bought a used 8000p and find the right channel sometimes drops in volume for a short time before returning. It seems worse right after being powered on, once warmed up after about 5-10min it seems to stabilise and not have this issue any longer. I have been testing this by joining the left/right inputs together so they play the same source (in mono). I measured the bias as and found the left channel was almost zero and right a bit higher than expected. Both about 25mV now. I can’t see any overheated components or other damage (the right side +12V dropper resistor PCB through hole is a bit brown on one leg but not bad). Any ideas welcome as to what it could be!