With no differential transistors, does the base-emitter voltage change on the driver transistors with the drivers in or out of the circuit?
No there isn any significant change on the B-E with no diff transistors installed. Q9 measure 0.45v and Q10 measures 0.01v.
I did find with no diff transistors, drivers installed and R61 lifted, the solder pad from Q9’s emitter to the positive rail pad on R61, measured 148ohm. R53 checks ok both in and out of circuit, no shorted outputs or other devices.
I’ve soldered in the diff and driver transistors and with sone fancy bending, I’ve connected the emitter of Q9 to the pos rail with a through hole equivalent resistor, without using the solder pads and copper trace.
Powered up and now the amp draws high current. I”ve rechecked all components for shorts, none found. That’s where I stopped last night.
I did find with no diff transistors, drivers installed and R61 lifted, the solder pad from Q9’s emitter to the positive rail pad on R61, measured 148ohm. R53 checks ok both in and out of circuit, no shorted outputs or other devices.
I’ve soldered in the diff and driver transistors and with sone fancy bending, I’ve connected the emitter of Q9 to the pos rail with a through hole equivalent resistor, without using the solder pads and copper trace.
Powered up and now the amp draws high current. I”ve rechecked all components for shorts, none found. That’s where I stopped last night.
Have you tried swapping the transistors between channels to see if all transistors worked as they should in the good channel?
Have you tried measuring the resistances on the good channel to see how they compare to the bad channel?
Have you tried measuring the resistances on the good channel to see how they compare to the bad channel?