Electro Harmonix XO Octave Multiplexer Analog Sub-Octave GeneratorGet down! Generates deep, phat bass tones one octave below the notes you play. Two separate smoothing filters enable you to tailor your sub octave signal to the exact bass sound you desire, separating the Octave Multiplexer from other octave devices. Run your vocals through it and sound just like Ike Turner. This is a monophonic device and works only on single notes. True bypass Create very smooth and natural bass tones one octave below your played