I get occasional crackling noise in the right rear channel. It´s not the speaker and the noise is there on all inputs. The very odd thing is that it doesn´t seem to be linear with the volume level.

All, I posted this at DIYMA, and didn't get too may helpful responses, so figured I'd ask the Hive Mind. Back in the '90s, I used to set amp gains by turning the level pot all the way up and then ...