An audio amplifier is to transition between a power-down mode and an active mode, based on assertion and deassertion of a power down signal. A power down control module is to selectively assert and deassert the power down signal to the audio amplifier. The power down control module may identify at least one of a digital detection signal and an analog detection signal. The digital detection signal indicates the availability of a digital audio signal to be amplified, and the analog detection signal indicates the availability of an analog audio signal to be amplified.