Abstract: An electronic audio device, such as a radio having an audio loudspeaker is described, as well as a method of operation of such a device. The device has an audio stage (6) having an audio output for providing an audio output signal, an acoustic transducer (12) coupled to the audio output for outputting an acoustic signal and a microphone element (13) acoustically coupled to the acoustic transducer to provide a feedback signal representative of the output of the acoustic transducer. A comparison circuit (15) compares parameters of the audio output signal and parameters of the feedback signal; and a control circuit (16, 24, 50) responsive to the comparison circuit controls the audio stage when a parameter of the feedback signal differs from that parameter of the audio output signal by a predetermined amount.

Abstract: An amplifier structure (200) includes a main amplifier loop (203) for efficiently amplifying an input signal at a power amplifier (228) coupled to a load susceptible to impedance variations. The amplifier structure (200) includes a DC correction circuit (214) for detecting and correcting misadjustments in the amplifier (200) in order to eliminate DC offset associated therewith.