Sega Genesis 1 va3 pcb taiwan

Sorry for bad english. I have a problem with the sound on the board genesis 1 va3 taiwan, , If you increase the volume on the headphones, there is distortion of the sound if playing FM + PSG Game SEGA GENESIS , small volume of headphones distortion sound . Master Sysytem game for flashcards play sound normal no distortion only PSG sounds great at a small volume of headphones out silence As it should be .

Replaced all the capacitors did not help - sound distorted .

PSG from capacitor C40 no distortion sound .

http://gamesx.com/wiki/lib/exe/fetch.php?media=schematics:genesis_sound_and_video.png

Please , tell me very much I ask from what point to take the signals that would mix the signals in mega-amp and what circuit to use for va3 board genesis 1 .

1) https://www.sendspace.com/file/s4b6wi headphone out low volume to high UMK3

2)cxa1034p pin 1 and 8 distortion sound also .

3) Actually ym2612 pin 21 (MOL), 22 (MOR) if you take the signal FM from there no distortion. And PSG singly pin С40 capacitor no distortion sound .

4) LM358 from mono signal sound distordion also.

Can you show the mixing points in mega-amp fron board va3 model 1 .

Native amplifier and mixing is completely not working sound distorted((

Please Help .

cxa1034p mixng FM+PSG sound on the board? If it broke without it you do not mix FM + PSG?