Noise when using input selector switch

[Nuuk]

I mean input pin directly on the amp board, AFTER the switch, not the RAC input jack on the box. Just to be sure. Do you have a coupling cap?

Aha! OK, I already have 47K directly on the input after the attenuator. No, there is no coupling cap.

[moamps]

Does it happen when you do not switch the sources' grounds?

[Nuuk]

Does it happen when you do not switch the sources' grounds?

Somebody had suggested not switching the source grounds Moamps and that would have been my next job.

But I tried something else first! I was using the 4 pole 3 way switch for two inputs and using the third position for mute. I had 47K resistors soldered across the pins of the switch. I changed the arrangement to make the switch a 2 way and did away with the resistors. And voila, no more noise when switching.