Highly doubt it, i will change it but even with no input from the pre amp, there should be switching in the class D, the PWM is not generated there. Pre amp only carries the analog signal. Even if you remove the cap entirely we are just decoupling the pre amp from the class D, nothing else.
At NE5532 pin 6 there is also -->10k resistor --> Zener -->100k resistor --> GND not sure what is this all about. I still don't think the voltages at NE5532 are correct.
At NE5532 pin 6 there is also -->10k resistor --> Zener -->100k resistor --> GND not sure what is this all about. I still don't think the voltages at NE5532 are correct.
I don't think they're right. A leaking capacitor could interfere with correct biasing.
Check for pulses while the cap is out of the circuit.
Check for pulses while the cap is out of the circuit.
Do you still have 33.6v on pin 5 of the 5532?
Are the 16 ohm resistors at the speaker terminals within tolerance?
Are the 16 ohm resistors at the speaker terminals within tolerance?
Do you still have 33.6v on pin 5 of the 5532? = yes
Are the 16 ohm resistors at the speaker terminals within tolerance? = yes
Are the 16 ohm resistors at the speaker terminals within tolerance? = yes
If you connect a speaker or dummy load across the speaker terminals, do you read any DCV across it?
Does that correct the biasing issue and allow pulses to be produced from both IC?
Try. If the circuit is still in production, they won't release it.
Try. If the circuit is still in production, they won't release it.
Does that correct the biasing issue and allow pulses to be produced from both IC? = no, it does not.
But if you try to start the amplifier while having a load hooked up, it won't. It will go into protect.
Adding a dummy load while the amp is already running does not make it go into protect.
But if you try to start the amplifier while having a load hooked up, it won't. It will go into protect.
Adding a dummy load while the amp is already running does not make it go into protect.
Is there a 20k resistor connected to pin 5 of the 5532?
If so, does removing it make a difference in the drive or on the voltage on pin 5 of the 5532?
If so, does removing it make a difference in the drive or on the voltage on pin 5 of the 5532?
Removed it. No difference.
The side of the resistor directly connected to pin 5 from the 20k resistor stays at 35v.
The other one is at 30v.
The side of the resistor directly connected to pin 5 from the 20k resistor stays at 35v.
The other one is at 30v.
I don't know how much more time you want to spend on this but if you could find a few points on the circuit, it would make things easier.
For example, what is the voltage across and the value of C138?
For example, what is the voltage across and the value of C138?
For example, what is the voltage across and the value of C138?
C138 = 10.3v (Tied to pin 1 IC1)
C148 = 10.3v (Tied to pin 1 IC2)
C138 = 10.3v (Tied to pin 1 IC1)
C148 = 10.3v (Tied to pin 1 IC2)
How much more time are you willing to put into this amp? This is going to be a slow process and will take quite a few more posts and may not be successful.