You may. Try turning the input/gain down and the master up.

This is happening because the power supply section of the guitar amp is being maxxed out, and the pilot lamp dims a bit in response to this. Bass notes tend to pull more current, making the lamp dim more when the kick hits. This happens in a LOT of gear, some PA gear will do this. The only damage that you may come across is blowing the speaker drivers. Because of the clipped waveform (courtesy of the overdriven power amp section) and the low frequency AND transient peak of the kick drum (like a gunshot), the Ampeg's Eminence speakers can handle only so much torture before they will eventually blow out. Cleaning up the sound will save the speakers' lives, but there goes that gnarly distortion you were wanting.All you really have to do is turn the Master so that there isn't so much swing from the power amp clipping. Let the preamp section do the "fuzzing up"...