Korg Pa50 Low Volume

Hi,

I have a perfectly working korg pa50 arranger with low volume. It slightly goes up a little after turning it on for 10-15 minutes but still is low. Did many tests, checked supply voltages,and reviewed the schematics and isolated it to the signal coming from the main board.

When using the back inputs, the amp is low and clear. When sourcing the outputs to an external amp, it is low.

I can take it apart to dig into the main board but was hoping if someone has experienced it and can give me some hints .

The output is clear and balanced, ie both channels are equally low and go up slightly as the keyboard warms up.

When compared to pa1x, it barely reaches 1/4 of the 1x loudness with volume maxed and being in for an hour.

The volume knob was replaced and is new. The issue was the same with the old pot too.

Any ideas ?

Thanks

did this work?

I’ve ordered the op-amp. Haven’t received it yet.