MXR M288 Bass Octave Deluxe The M288 Bass Octave Deluxe is a dual-voice octave pedal from MXR Bass Innovations that offers organic analog tone, true bypass, and a wide variety of tone-shaping options. Powered by a single 9-volt battery, MXR's 18-volt Constant Headroom Technology™ (CHT) provides studio-performance headroom and superior tracking. Use the Dry knob to mix your direct bass signal with the octave effect, or hit the Mid+ switch to add up to +14dB of internally adjustable low-mid punch (400Hz) or midrange pop (850Hz). Bass players will love the two separately processed and individually voiced octave controls-Growl (for throaty, midrange octave-below tone) and Girth (for deep and smooth octave below). The Bass Octave Deluxe comes in a durable, lightweight aluminum casting and has the same high-quality jacks and switches that have made MXR pedals the road-ready standard on pedal-boards around the world for over 30 years.