Electro-Harmonix Bass9 Bass Machine Pedal (Used)Includes box and product guide The polyphonic BASS9 Bass Machine transforms a guitar into nine different basses and requires no special pickups, MIDI or instrument modifications. It relies on the same technology powering all EHX 9 Series pedals, like the award winning MEL9 Tape Replay Machine, but features a new algorithm maximized for transposing one to two octaves down with superior dynamics and tracking. A rotary switch allows the user to select