center negative

Center negative describes a DC power connector polarity in which the center pin of the barrel plug carries negative voltage and the outer sleeve carries positive, a standard used by many pedal power supplies¹. Manufacturers specify it as a power requirement for pedals, for example 9V DC center negative²,³, 18V DC center negative⁴, or regulated 9VDC center negative only⁵. Pedals list a center-negative power supply input among their connections⁶,⁷, and power distribution units provide center-negative DC outputs for supplying multiple pedals⁸. Some positive-ground circuits include a voltage inverter or charge pump acting as a polarity reverse circuit so the pedal can run on a standard center-negative adapter while keeping its original operation, and in one case allowing daisy chaining with other pedals⁹,¹⁰.