Abstract: A system for controlling the gain of an input signal in an audio signal amplifier. The system includes a user-operable gain control, and analog and digital circuit elements that together are configured to modify the gain of the input signal in response to the user-operable gain control.

Abstract: A system for controlling the gain of an input signal in an audio signal amplifier. The system includes a user-operable gain control, and analog and digital circuit elements that together are configured to modify the gain of the input signal in response to the user-operable gain control.

Abstract: A method and audio signal processor for detecting feedback in an electrical amplification system divides a frequency spectrum into a plurality of frequency bands, classifies a tone present in an incoming audio signal into one of the plurality of frequency bands based on a frequency of the tone, selects a threshold value based on the frequency band into which the tone is classified, and disqualifies the tone from potentially being feedback if an amplitude of the tone is greater than an amplitude of a harmonic of the tone by less than the threshold value. The tone is deemed to be potentially feedback if the amplitude of the tone is greater than an amplitude of a plurality of harmonics of the tone by at least the threshold value.

Abstract: An apparatus for driving speakers includes user-configurable amplifier cells for driving selected speakers, a synchronous rectifier circuit, and a control system. Each cell connects between power rails. The rectifier circuit provides current on the rails for consumption by the cells. The current depends on the configuration. The control system implements a model of the rectifier circuit and cells and uses it to control an audio input signal in response to information concerning electrical outputs of the amplifier cells. This indirectly limits current drawn from the synchronous rectifier circuit.

Abstract: A method and audio signal processor for detecting feedback in an electrical amplification system divides a frequency spectrum into a plurality of frequency bands, classifies a tone present in an incoming audio signal into one of the plurality of frequency bands based on a frequency of the tone, selects a threshold value based on the frequency band into which the tone is classified, and disqualifies the tone from potentially being feedback if an amplitude of the tone is greater than an amplitude of a harmonic of the tone by less than the threshold value. The tone is deemed to be potentially feedback if the amplitude of the tone is greater than an amplitude of a plurality of harmonics of the tone by at least the threshold value.

Abstract: An apparatus for driving speakers includes user-configurable amplifier cells for driving selected speakers, a synchronous rectifier circuit, and a control system. Each cell connects between power rails. The rectifier circuit provides current on the rails for consumption by the cells. The current depends on the configuration. The control system implements a model of the rectifier circuit and cells and uses it to control an audio input signal in response to information concerning electrical outputs of the amplifier cells. This indirectly limits current drawn from the synchronous rectifier circuit.