Recently upgraded my mixer, and now I notice my Matrix 6R is fairly noisy. It seems to have a low level noise and synth rumble on all the patches. What's unique is that the sound changes from patch to patch, but is always there. You can here it when the synth is not being played, and I've even removed the midi cable, and turned everything else off, just the module and the mixer........

I guess I could turn the main volume down on the unit, but is there something else I could do


Should I replace the caps, and where are they and what do they look like

Is this common