Had my Boogie (60w MarkIIC+ - no graphic or reverb) for years and had this problem all the while. Using the drive channel, even with the master on 0, its too loud compared to the clean channel, the treble shift (which I love) makes it worse. Can't adjust the balance so for gigging end up using a pedal for drive sounds. Love my amp and would love to solve this problem once and for all. Any help would be greatly appreciated.