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. Specifications Big Muff Knob Layout - familiar Sustain, Tone and Volume controls Mids EQ - fully parametric Mids EQ includes variable frequency sweep, boost or cut level control and switchable Q or bandwidth amount Footswitch for Mids EQ -turn on the Mids EQ circuit with the stomp of your foot Gate - remove unwanted hum Attack -preserves pick attack with an enhanced version of your dry signal Bass Boost - switchable bass boost Expression Pedal Input - sweep the frequency of the MIDS EQ with your foot True Bypass