An audio amplifier comprising a Class D audio amplifier having an input receiving an analog input signal, a pulse width modulation stage for converting the analog input signal to a pulse width modulated signal, a driver stage receiving the pulse width modulated signal and for producing a driver PWM signal and an output switching audio amplifier stage receiving the driver PWM signal and providing an amplified PWM signal; an output filter stage receiving the amplified PWM signal for converting the amplified PWM signal into an analog audio signal; and a linear output amplifier stage receiving as inputs the analog input signal and the output of the output filter stage, the output of the output filter stage serving to bias the linear output amplifier stage. In one embodiment, two floating power supplies are superimposed on the output of the filter stage for biasing the linear amplifier, one at a preset voltage above the output signal of the filter stage and a second at a preset voltage below the output of the filter stage. The linear output amplifier stage provides an analog output to a sound reproduction transducer.