A digital audio system to store and reproduce a digital PWM signal and a
method of processing an audio signal. The method includes; converting an
audio source signal into a digital pulse width modulation (PWM) signal
through a series of signal processing processes and storing the PWM
signal in a separate storage medium, when an audio signal is reproduced,
reading the digital PWM signal stored in the storage medium and decoding
the signal into an analog PWM signal, and performing a power switching
operation with the decoded analog PWM signal and extracting an audio
signal.