The Tech 21 Sans Amp Bass Driver is the bassists solution to acquiring three interchangeable tones at the press of a switch. The all analog circuitry features the same controls as its single channeled predecessor: Drive, Bass, Treble, Presence, Blend and Level. To achieve a number of classic and modern tones has never been easier. Through tweaking the various knobs the user can find a tone then double tap on a foot switch to save it.