Audio Frequency Amplifier is an amplifier that has one or more transistor stages designed to amplify audio-frequency signals.
An amplifier that operates in part or all of the frequency range 20 Hz to 20 kHz. High-fidelity amplifiers function over a somewhat wider range (e.g., 10 Hz to 50 kHz).
See also, Audio Amplifier Linear Amplifier Difference Amplifier Buffer Amplifier
is an electronic amplifier that strengthens low-power, inaudible electronic audio signals such as the signal from radio receiver or electric guitar pickup to a level that is strong enough for driving (or powering) loudspeakers or headphones.