I have a Peavey ValveKing 112 that is making a strange noise. On certain notes I get an almost gurgling noise from the amp. It's not very loud it's kind of a background noise. Could this be due to a tube that is ready to die? These are the original tubes but the amp is less than a year old (bought it Xmas 2007). I don't play loud ever, I use this amp in a bedroom in my house and I don't think that I've ever had the volume past about 9 o'clock.