Abstract: An audio processing circuit that is adapted for operation in a partial distortion mode of operation particularly when transitioning from partial distortion to clean signal operation and including a gain control circuit for sensing the level of the audio signal to control gain so as to increase output signal gain as the volume control is decreased in volume. The circuit also includes a sensing circuit for sensing the audio level to boost high end signal content as the volume control is decreased so as to maintain high end or treble signal content at low volume.