AMPSDiscrete (no opamps) F.E.T Hi-Gain Distortion and discrete F.E.T Overdrive/Booster IN ONE BOX. You could think of them as 2 separate pedals in one box...or think of them as stages to be linked together for endless combinations. Hi-Gain side has Volume, Distortion knobs, Bass, Mid, and Highs minipots. Booster Side has Volume, Overdrive knobs, Bass and Highs minipots.(these new hi-Q sealed minipots don't break BTW) Hard clipped distortion (the way most pedals achieve distortion) at one point in a circuit can be cool, but stage after stage of FET (GT-500) is very real, very amplike, has ridiculous amounts of sustain even at low volume, does the great chunky low string rhythm stuff and cleans up incredibly well when you turn down the guitar's volume.