What is a characteristic of a Class A amplifier?

A Class A amplifier is characterized by its ability to conduct current continuously, even in the absence of an input signal. This means that current flows through the amplifier at all times, allowing it to provide a linear amplification of the input signal. Because of this continuous current flow, Class A amplifiers typically exhibit very high linearity in their output, which results in high-quality audio reproduction with low levels of distortion.

The feature of constant current flow makes Class A amplifiers less efficient than other amplifier classes, as they consume power continuously, regardless of whether there is an input signal to amplify. This is a distinguishing aspect that sets them apart from more efficient amplifier designs that switch off during periods of no input.

In contrast, other classes of amplifiers, like Class B and Class D, either do not conduct current without an input signal or use switching technology to improve efficiency.