SansAmp Bass Driver DI Effects Pedal. 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. The core of the SansAmp Bass Driver and all of its tones remain true to its original design. CONTROLS Presence: Controls the amount of definition and upper harmonic content Drive: Adjusts the overall gain structure and overdrive Level: Regulates the XLR and effected 1/4" output levels Blend: Allows you to mix the direct bass signal with SansAmp Tube Amplifier Emulation circuitry (which is particularly useful for basses equipped with piezo pickups) Bass & Treble: Active EQ controls, specifically tuned for bass guitar, that cut or boost +/- 12dB