AbstractThe introduction of digital technology to audio electronics has become widespread over recent years and it is becoming increasingly desirable to produce a completely digital power amplifier to take over from its analogue counterpart. Class D amplification, which uses the principle of pulse-width modulation (PWM), can be adapted to perform the role of a completely digital power amplifier. The purpose of this paper is to show how distortion is introduced by the PWM sampling process used in the class D amplifier with particular reference to a bass-midrange amplifier with a bandwidth of 6 kHz. A new sampling process is presented which can enhance the performance of the amplifier by introducing lower levels of distortion compared with the usual natural and uniform sampling processes. In addition it is shown that the new sampling process is suitable for implementation in a completely digital system through the use of a digital signal processor.