The amp had a few shorted outputs on the high side so I replaced all the outputs, octocouplers and op-amps in output section. Under 12 volts of input I have rail to rail oscillation, once I crack the voltage above 12 volts rail to rail oscillation disappears and I’m left with the following image below. Powersupply functions like it should under or above 12 volts.
Attachments
On BOTH ends of the resistor or just on the muting transistor end of the resistor?
You may have to drive a signal into the amp to see the amplitude of the signal change.
You may have to drive a signal into the amp to see the amplitude of the signal change.
Yes, I lose rail to rail when a signal is inputted and when I turn the voltage from my powersupply above 12 volts. The image above is the signal when a input signal is provided to the amplifier.
That is the signal on both ends of the R4110 when a signal is inputted is what that message was supposed to say.
Yes, the pre-amp board is installed. I tested a 40hz tone and 100hz tone and produced the same results.
Do you see your drive signal on the resistors (end closest to the edge of the board) 4011 and 4016?
On R4011 I have the drive signal on both ends of resistor. On R4016 I have -14 volts on both ends of the resistor.
With a 40hz tone inputted
Pin1 0 volts
Pin2 0 volts
Pin3 0 volts
Pin4 14 volts
Pin5 0 volts
Pin6 0 volts
Pin7 0 volts
Pin8 -16 volts
Pin1 0 volts
Pin2 0 volts
Pin3 0 volts
Pin4 14 volts
Pin5 0 volts
Pin6 0 volts
Pin7 0 volts
Pin8 -16 volts
Follow the circuit from the output pins of that op-amp to the two resistors (4011/16) to confirm that the outputs of this op-amp drive those 2 resistors.
I just realized I was looking at the wrong resistor for R4016 I have the drive signal on it. And yes the outputs of the NE5532 go to resistors 4011/16.
Do you see your drive signal on the output terminal of the left-most op-amp (near the resistors) when you lose r-r oscillation on the outputs?
