Gain Amplifier

An amplifier or amplifier stage that doesn't actually amplify, namely the output is the same as the input. It does have useful purposes, for example to prevent signals internal to a system from leaking out of an input jack or port, or to convert from a low voltage high current circuit to a high voltage low current circuit or vice versa. This writer has seen radios with several unity gain audio driver stages designed for the sole purpose of having the radio possess the number of transistors it was advertised to possess.