Slight distortion in power amplifier


2016-01-12 9:16 pm
I have a Duson B100 and allthough it functions, i sense a slight distortion in both channels.
But i can't find the cause, no parts are defective...
However have not yet replaced the main caps, as they are in total 8x 4700 uf.
It's on the low end of the freq spectrum... where i can hear it most.
However also on the midrange, as i played a cd of a band that i recorded and mixed and i can hear a slight edge of saturation on vocal lines.

If i was to play straight up death metal i doubt it would be noticeable.

The end signal does not go through fuses, it's relay protected.

Anyone got a hint where to look at?