[String7th]

I'd first set the reverb and delay to 0, that's probably the main source of any mud coming from the amp. A lot of guitarists think they need to add reverb and effects to thier amp directly but all it does is add a color to the amp only describeable as butthole.

The channel switch delay is a part of the amp. Aside from downloading any driver updates Peavy may offer, you are stuck with it. Are you familiar puch overdubing and punch in/out in reaper?

Those heaphones are prob ok to work with.