Then Amplifier Classes is the term used to differentiate between the different amplifier types.Īmplifier Classes represent the amount of the output signal which varies within the amplifier circuit over one cycle of operation when excited by a sinusoidal input signal. One method used to distinguish the electrical characteristics of different types of amplifiers is by “class”, and as such amplifiers are classified according to their circuit configuration and method of operation. A typical loudspeaker has an impedance of between 4Ω and 8Ω, thus a power amplifier must be able to supply the high peak currents required to drive the low impedance speaker. Generally, large signal or power amplifiers are used in the output stages of audio amplifier systems to drive a loudspeaker load. The main operating characteristics of an ideal amplifier are linearity, signal gain, efficiency and power output but in real world amplifiers there is always a trade off between these different characteristics. Not all amplifiers are the same and there is a clear distinction made between the way their output stages are configured and operate.
