...in that, when you turn it on, it vibrates. (Out of the gutter, please. ) It is an 80s Peavey combo. Most amps ime will hum or not, but this one has vibration as if from a fan, and actually feels and, although just barely audible, sounds a lot like a gaming PC case. This amp has no fan. It is also not a gaming PC. Are the above signs of an impending failure? ...or possibly just an old machine running as designed? It sounds very good and sees almost daily use, but, I stress because, me. Thanks.