MXR M133 Micro Amp Effect Pedal

This device adds a preset amount of gain using a single control. With a guitar, this lets you boost your signal for lead work, adjust between two different guitars with unmatched output (i.e., humbucker to single coils), or it can supply a permanent boost in a long effects chain where signal drop-off is a problem. Controls: Footswitch toggles amp on/bypass (red LED indicates on). Gain knob adjusts total output volume when micro amp is engaged. Power: Single 9-volt battery or Dunlop ECB-003 AC adapter (not included).