The Electro-Harmonix Hot Tubes OD reissue was designed to replicate the organic overdrive of a vintage tube amp. It has controls for Volume, Tone, and Overdrive knobs plus a Tone On/Off switch. Volume sets overall output level while Overdrive adjusts gain. The Tone control adds warmth or sizzle, and the player can disengage the Tone circuit for a more-transparent sound. True-bypass switching preserves signal integrity while the pedal is not in use. The pedal is housed in a compact die-cast package with a 9-volt battery and can be powered by an AC adapter. Read more at www.ehx.com.