I got my repaired head back the other day...and i popped it into my rack, with my power conditioner, tuner, and compressor. I plugged into my head and let her rip. There was a massive clipping noise coming from my cab. I have an 810E brand new. I thought my head was still messed up. So i took it back to long and mcquade and we tested it. NOTHING was wrong...really weird eh? Now we came to the conclusion that its the POWER where i was plugging in to. I plugged into a different outlit across the room and the sound went away...Has anyone ever expereinced this?