M196 The A/B Box allows you to route your instrument's signal to two separate output amp paths, with a Thru jack for use with a tuner or other device meant to receive a constant signal. This pedal can be powered by a 9-volt battery, a Dunlop ECB003 9-volt adapter, or the DC Brick™, Iso-Brick™, and Mini Iso-Brick™ power supplies (not included).