Electro Harmonix US-BM Big Mu Pi (Classic)The Electro Harmonix US BM Big Mu Pi replicates the appearance and sweet, singing tone of artists from Jimi Hendrix to Santana to Korn. 3 controls that let the player dial in the finest harmonic distortion sustain ever produced. Volume control adjusts the output level. Sustain control optimizes the long sustain with just the right amount of harmonic distortion. Tone control provides a range of sounds, from warm bass to crisp treble. The distortion