Simple Explanation

How much louder a signal is made by an amplifier or audio device.

Concise Technical Definition

The amount of amplification applied to an audio signal, typically expressed in decibels (dB) as the ratio of output level to input level.

Layman-Friendly Analogy

Like turning up the brightness on a flashlight—the beam gets stronger, just like gain makes a signal stronger.

Industry Usage Summary

Gain controls are found on mixers, preamps, and amplifiers to set input signal levels before further processing. Too much gain can cause distortion; too little can result in weak or noisy signals.

Engineering Shortcut

Signal boost (Vout/Vin); usually in dB.

Full Technical Explanation

Gain refers to the increase in amplitude or strength of an audio signal as it passes through an active electronic component such as an amplifier. It is often measured in decibels (dB) and represents the ratio between the output signal and the input signal—either in voltage, current, or power. Gain is a critical parameter in signal chains; proper gain staging ensures optimal signal-to-noise ratio and prevents distortion. In practical use, gain differs from a volume control in that it typically sets the input sensitivity, affecting tone and headroom, especially in preamps and mixers.