Getting the '68 Vibrolux to go from clean to overdrive takes some skill. If you are not careful the speakers can flap if the amp attempts a bowel movement. Some owners notice that the 6L6 tubes can produce low end frequencies and that can translate into the power section trying to output all of that either clean or overdriven. If the dynamics go way beyond the operational limits then you get the amp dumping power and the speakers flapping - it sounds horrible. So, to solve this problem: EQ the low end to avoid the amp giving a burping sound when loud. Then get a compressor in the front end, something like an Empress compressor, with variable compression ratio. Then you have armed the '68 Vibrolux to be a deadly weapon. The '68 Vibrolux has a lot going for it: 6L6 power tubes, almost twice as much power as the similar sized and weighted Deluxe, two 10" Celestion rock and roll speakers, custom channel that gives a tweed sound option, classic tube driven reverb and vibrato, footswitch and amp cover.