Built with stacked FET-based circuitry for an injection of grit in your overdrive, the Electro-Harmonix Operation Overlord Allied Overdrive is a versatile stomp box providing warm presence for a shop's worth of instruments. Adjust the Input Level switch to accommodate guitars or keys and dial in the three-band EQ and boomy Bass knob for throwback tube tone with the stomp of a switch. There's even a separate boost channel and stereo ins/outs to push your playing dynamics and tone past the frontline.