BOOSTER PEDAL Clean Boost pedal. Very versatile. 2-band active equalizer. 12dB boost. Transparent bypass. Internal voltage doubler from 9V to 18V. Controls: Oil (Boost), Treble, Treble Frequency (850hz-8.2khz), Bass and Bass Frequency (120hz-1.2khz). Also useful for bass or acoustic guitar. It works with a 9V battery or optional power supply not included. Current consumption: 28mA.