The Deluxe Big Muff Pi Pedal from Electro-Harmonix is a harmonic distortion-sustain device pedal developed for the electric guitar player. The Deluxe Big Muff includes seven knobs: The Volume knob is a master volume control for the entire pedal. The Tone Knob provides a range of sounds from high treble to deep bass. The Sustain knob adjusts the amount of sustain and distortion. The Attack knob is a volume control for the Attack effect. Turning the Gate knob clockwise raises the Gate threshold requiring greater input amplitude to open the noise gate, allowing your notes to be heard and your instrument to pass through. The Mids Level knob either boosts or cuts up to +/- 10 dB, at the frequency set by the Freq knob located below it. The Deluxe Big Muff also includes a Bass Boost/Normal Switch, a Mids Q switch (high / low), a Mids footswitch, and a Bypass footswitch.