In a recent gig my practice amp, only the third time i have gigged was far too quiet, usually I would borrow a friends but my drummer said he had a rig lying around so he brought it round and it turned out to be a Laney DP 150 and a 2x15 cab from the same era and series. It goes crackly when you put it past five on the volume and when you play and change the knobs, why is this? And could anyone tell me more about these amps and your opinions?