MXR M288 Bass Octave Deluxe The M288 Bass Octave Deluxe is a dual-voiced octave pedal from MXR Bass Innovations that offers organic analog tone, true bypass, and a wide variety of shaping options. Powered by a single 9-volt battery, MXR's 18-volt Constant Headroom Technology (CHT) delivers studio performance headroom and superior tracking. Use the Dry button to mix your direct bass signal with the Octave effect, or press the Mid+ switch to add up to +14 dB of Bass-Mid (400Hz) or Midrange (850Hz) Punch adjustable internally. Bassists will love the two separately processed, individually voiced octave controls: Growl (for guttural, midrange octave-below notes) and Girth (for deep, smooth octaves below). The Bass Octave Deluxe comes in a durable, lightweight aluminum casting and features the same high-quality plugs and switches that have made MXR pedals the road standard for cranksets around the world for over 30 years.