The Electro Harmonix Bass Preacher Bass Guitar Effects Pedal is a compression pedal especially designed to tackle the lower frequencies in the bass register, suitable for both active and passive instruments, and is packaged in a rugged user friendly chassis.
Bass guitars possess a huge dynamic range and produce powerful low frequencies. Designed for and by bassists, this compact compressor/sustainer features fully adjustable controls that can subtly transform the dynamic qualities of a bass guitar or take them to the extreme. From transparently levelling out notes so they sit in a track to creating an intensely squashed sound, this pedal is highly effective at getting your message across in a professional no nonsense manner.
The main features of the Electro Harmonix Bass Preacher Bass Guitar Effects Pedal include:
Compact compressor designed especially for bass guitar
Input sensitivity ranges from -10 dBu to +2 dBu making it a perfect fit for both passive and active basses of varying output levels
Maximum gain reduction of 21 dB, with enough make-up gain to return your signal to full volume at maximum sustain (compression)
Attack toggle switch changes the timing of the onset of compression and provides three selectable settings: Fast, Medium and Slow
True bypass for maximum signal path integrity when in bypass mode
Tough, compact die-cast package
9-Volt battery included
Optional EHX9.6DC-200mA power supply available
Dimensions in inches: 2.75 (w) x 4.5 (l) x 2.1 (h)
OKKO FX Motörbass
Behringer Bass Brassmaster Fuzz
Electro Harmonix Bass Big Muff Pi Bass Fuzz Gui tar Effects Pedal 
TC Electronic SpectraComp Bass Compressor
Electro Harmonix Bass Clone