Just wondering if someone has had a problem with no distortion on dirty channels while using the 4 Cable Method. Really frustrating... is it the amp? or is it improper routing ? Something in the Global settings? 4 CM routing confirmed and re-checked. Using Meas Boogie MkV, channel switching working fine with TRS cable. We tried putting one cable into the front of the amp and it works fine, sent ins and outs from HX Effects through FX loop in MkV and worked fine, but in 4CM, after channel switching, channels 2 and 3 have no distortion and Master volumes within the channels are disabled. Making arrangements to get the head into the shop but I figured I'd try on this forum.