The Mastotron is a sub-heavy silicon fuzz with some new twists: An input impedance control that adjusts for weaker passive pickups (turn all the way to "push') or for active pickup basses and guitars (turn down a bit), or to line level for re-amping ("relax"). It works very well for re-amping bass tracks that need to be fuzzed up after tracking, and keyboards, which usually overload fuzzes. There's also a three-position sub control switch, a treble tone control, flexible pulse width control for square to narrow pulses, and a wide fuzz depth control. More flexible than any silicon fuzz to date, the Mastotron is part of the new Vextron series with heavy paint, a single silkscreen layer, and the new black 3PDT switch. Rock!