This amp I have was serviced by professionals just recently, and I was wondering if it should be ripping my head off loud. I remember about 5 years ago this amp was awesome, but I don't remember how loud it really was. It has 250w/4ohms on the back, I'm running it through a 4 ohm cab. I have it halfway up and the hum of the amp being on is louder than the bass signal. Am I crazy or is it supposed to get to the loud levels after a certain point?