Abstract: For overcurrent protection of a switch-mode power supply in a high power audio amplifier, an active feedback overload shut-down circuit acts though a control input of a PWM (pulse-width modulator) in the switch-mode power supply. In a multi-output switch-mode power supply, e.g. a dual-rectifier supply providing .+-.53 volts and .+-.100 volts suitable for a class H amplifier, instantaneous currents in each of the two rectifier circuits are monitored by primary windings of a current-sensing transformer, providing from its secondary winding a signal that is rectified and monitored by a comparator-timer for current overload at a predetermined threshold. The primary windings are made to have a particular turns ratio so as to proportion the protection sensitivity for each dc output voltage. Upon sensing overload from either rectifier circuit, the comparator-timer applies a shut-down signal to the PWM, shutting down the power supply safely for a predetermined time period, e.g. 17 seconds.