The M288 Bass Octave Deluxe is a dual-voice octave pedal that offers analog tone, true bypass, and a variety of tonal options. MXR's 18 volt Constant Headroom Technology provides high headroom and superior tracking. Use the Dry knob to mix in your direct signal, and hit the Mid  switch to add up to  14dB of internally adjustable mid frequencies (400Hz or 850Hz). Finally, mix in two separately controlled octave voices%u2014Growl (for throaty tone) and Girth (for deep tone).