The Doomidrive is a version of the Univox Unidrive. A high output overdrive booster from the early 70's. It uses the same N.O.S. Matsushita 2SC859 transistors found in the originals. With the right setup it creates a very dynamic overdrive and can border on a fuzz distortion when coupled with an already distorted amp. The bottom knob lets you control the amount of bass entering the circuit. This makes it useful as a treble booster as well.