So i just noticed this today when fighting with some gawd aweful feedback issues that have been creeping up on me.

With my 6505+ Combo on the LEAD channel i can hear a difference in the "HISS" or amp noise when i press the crunch button on the Rythem channel. Then with the crunch button depressed if i turn the pre up on the Rythym channel the "HISS" gets louder. I would have expected this to have NO effect whatsoever but here I am wondering if this is actually the way this amp is designed? Does anybody else have this amp and can test theirs?
Might just head to gc today and have a listen to other 6505's to see if they are the same. i understand some of the pre amp tubes are shared between channels so wondering if thats why it does it..