Ap-3000

[megael9]

Low audio

 

[megael9]

This amp have very low audio. The power supply is Ok, and the pre +12 -12 is also good.
The problem is that the audio is very low, and there's a POP on power On.
Thanks in advance

 

[Perry Babin]

If that's the actual, complete model number, post a photo of the board.

 

[megael9]

Picture

Picture

 

[Perry Babin]

Is the audio output clean but low?

Do all controls work as they should on the front of the amp?

 

[megael9]

The audio is so low that it is hard to tell if it is clean, and All controls looks and feel Ok.

 

[megael9]

Do you know what's the audio IN pin for the driver card?

 

[Perry Babin]

Do you have rail-rail oscillation on the output transistors of both boards?

The following diagram should be close.
http://www.bcae1.com/temp/SLA1500.pdf

 

[megael9]

The schematic helped me to find the problem. It was the Op amp U1.
After it was replaced everything is working Ok.
Thank you Perry.