Patent ID: 8081781
Filing Date: 2011-12-20
Classification: H03F,H04S

Abstract:
1. An A/V amplifier selectively switchable between a multi-channel reproduction mode and a 2-channel stereo reproduction mode, the A/V amplifier comprising: a decoder that decodes a multi-channel encoded input signal and outputs a multi-channel signal in the multi-channel reproduction mode, or outputs a 2-channel stereo signal in the 2-channel stereo reproduction mode; a plurality of PWM amplifiers for amplifying an output signal of said decoder, corresponding in number to a number of channels in the multi-channel reproduction mode; a plurality of terminals connected to a plurality of speakers in one-to-one correspondence, for transmitting outputs of said plurality of amplifiers to said speakers; a channel selecting unit for selecting the multi-channel reproduction mode or the 2- channel stereo reproduction mode; and a switching circuit for switching a connective relationship between said decoder and said plurality of amplifiers, and between said plurality of amplifiers and said plurality of terminals according to the mode selection; wherein when said channel selecting unit selects the multi-channel reproduction mode, said switching circuit enables the output signal for each channel in said decoder to be sent to said plurality of terminals via a respective one of said plurality of amplifiers; and when said channel selecting unit selects the 2-channel stereo reproduction mode, said switching circuit enables at least two amplifiers among said plurality of amplifiers to be connected in parallel between output terminals for each of channels L and R of said decoder and said terminals corresponding to each of the channels L and R, and enables timing of noise in output signals of the plurality of amplifiers to be varied.