Bryston BD-225-1 AmplifierA Class D amplifier is a type of audio amplifier that uses a digital switching technology to amplify audio signals. It is also known as a switching amplifier or a digital (erroneously) amplifier. Un like traditional analog amplifiers, which use continuous voltage waveforms to amplify signals, Class D amplifiers employ a more efficient method that switches the input signal on and off rapidly. Features High Efficiency Pulse Width Modulation Compact Size