Tech 21 SansAmp Bass Driver DI V2 Presence, Drive, Level, Blend, Bass and Treble controls Three outputs: an effected XLR, effected 1/4 in. and parallel, uneffected 1/4 in. Phantom power operable, optional DC power supply or 9 V alkaline battery The SansAmp Bass Driver DI has been an arsenal staple for players and studios almost since the day it was introduced in 1994 This multi-function, multi-application pedal dials up big vintage tube tones, bright modern slap sounds, gnarly distortions, and all in between Since the popularity of 5- and 6-string basses has gone beyond fad status and become mainstream, Tech 21 added a switch to adjust the bass frequency to extend into those lower registers They also added a mid-range control and a switch to adjust its frequency