Much to my annoyance, I had to return my 2 month old Ashdown ABM 500 EVO II Head (dream amp) to the dealer after it suddenly started screaming at me in the middle of a rehearsal! Almost 2 weeks later I receive a replacement head (apparently a capacitor went on the old one). I get it home, plug it in to my Ashdown 4x10, and thankfully it works, but with a good dose of the dreaded speaker buzz! For godsake!!! I tried various cables, power points, with and without bass guitar plugged in, eq on and off, etc, etc... no change. How much cab buzz should one endure? (Btw, the original amp was quiet as a mouse. It also looked more insulated.) I don't want to turn into the customer from hell, but I'm going to take my whole rig back to dealer and see if they'd be happy with what they hear. Any advice? Maybe I should have bought that Ampeg rig after all...!?!