Sansui AU-9500 Channel Issue

[Diyengineer]

Hello,

I have a Sansui AU-9500. I noticed that one of the channels is lacking some mid frequencies making the vocals a little muddy on one channel.

Doing some troubleshooting I swapped the left and right driver boards and the problem followed. I'm not sure what I should go after on this driver board that might cause this problem.


I've attached some pics of the board and schematic for reference.

Thanks

 

[rayma]

The first thing to try is replacing the electrolytic capacitors: C801, C807, C815, C817.