[an-sa]

An amplifier is an electronic device that increases the power of a signal. It works by taking a small signal as input and producing a bigger signal as output. The input signal is typically a low-power signal from a source like a radio, CD player, or microphone. The amplifier increases the power of this signal so that it can drive a load, such as a speaker, headphones, or another amplifier. The process involves the use of active components, often transistors or vacuum tubes, which introduce gain into the circuit, allowing the output signal to be stronger than the input signal.