M281 This pedal combines the tone-sweetening magic of the Echoplex® Preamp with a three-band EQ and midrange frequency adjustment so that you can dial in the perfect bass tone to punch up a solo, boost your signal in a live mix, sculpt more edge into the sound of a passive bass, and more. This pedal can be powered by a Dunlop ECB003 9-volt adapter, or the DC Brick™, Iso-Brick™, and Mini Iso-Brick™ power supplies (not included).