For op-amps in a circuit that uses local feedback (this circuit), the output and inverting input of each op-amp section should closely match the non-inverting input.
That's essentially what you have.
The voltage that you saw change with the gain selector change is due to a change in local feedback.
Without a scope, it's difficult to know for certain whether the amp is 100% healthy. It likely is if it sounds OK, especially with the numbers you last posted.
That's essentially what you have.
The voltage that you saw change with the gain selector change is due to a change in local feedback.
Without a scope, it's difficult to know for certain whether the amp is 100% healthy. It likely is if it sounds OK, especially with the numbers you last posted.
It remains only to find a replacement for Q318 - 2SB1076M, instead of it there is still TIP107. Thank you very much Perry for your help and health during this difficult time.
Without Q319 in the circuit, does the amp produce audio? If so, I'd try virtually any transistor with a pin configuration that will match. Higher hfe is better but it's may not be that critical.