MXR M288 Base Octave Deluxe The MXR M288 Bass Octave Deluxe effectively doubles the sound of an electric bass guitar by adding a parallel signal that's one octave lower than your natural tone. The M288 lets you manipulate and alter the sound of the sub-octave tone to suit your needs, to produce some powerful and amazing bass effects. Watch the two videos we've provided, to get a quick idea of what this means. It runs on a single 9 volt battery, a Dunlop ECB-003 AC Adapter, or a Dunlop DC Brick. What you get is a dual voice octave pedal that offers organic analog tone, and a wide variety of tone shaping options. Two Independent Octave Voices Growl Octave - for a throaty octave-below tone Girth Octave - for deep;, smooth voicing for octave-below tone Dry Control - to mix your natural signal with the octave effect Mid Switch - adds up +4 to +14 dB of internally adjustable mid-range punch at 400 or 850 Hz, to connect the highs and the lows True Bypass - straight through signal path (effects OFF), for a clean through put Exceptional Tracking - octaves that don't decay or drop out, all the way down below low E Constant Headroom Technology (CHT)* - for power and studio performance headroom All aluminum case 9 volt / AC adapter *Constant Headroom Technology� The M288's CHT circuit produces 18-volts of headroom from a single 9-volt battery or external power source. CHT utilizes voltage step-up techniques, which supplies constant 18-volt headroom regardless of source voltage. For example, CHT will produce 18-volt headroom from a used battery down to 4.5-volts and voltages up to 30-volts. CHT also protects against incorrect reverse polarity and AC voltages. Click here to see our other effects pedals.