I checked both guitar inputs as well as the amp connections. The only that makes any unwanted noise is the footswitch cable if you really pound on the jack.

This type of crackling only seems to happend when I physically play. I was considering an amp tech ( I only go to Steve's ). But I need the amp the next two weekends and their usual turn around is 1-2 weeks. I'm gonna play around with it again tonight to see what I can find.