What is Input Gain?
Input gain, often referred to simply as “gain,” is the amplification applied to the incoming audio signal before it is processed and outputted by the amplifier. It determines how much the input signal’s voltage is increased or decreased before being sent through the amplifier’s circuitry.
Functionality:
Input gain serves several purposes in a hi-fi amplifier:
1. Signal Amplification: The primary function of input gain is to amplify the weak audio signal received from the source component, such as a CD player, turntable, or media streamer. By boosting the signal strength, it ensures that the audio signal is at an optimal level for further processing without introducing noise or distortion.
2. Matching Signal Levels: Input gain allows you to match the levels of various audio sources connected to the amplifier. Different sources may output signals at varying levels, and adjusting the input gain ensures uniformity in volume across different sources, preventing sudden jumps or drops in volume when switching between them.
3. Pre-amplification: In some amplifiers, particularly those with separate preamp and power amp stages, the input gain acts as a pre-amplification stage. It prepares the signal for further processing by the power amplifier stage, enhancing the overall signal-to-noise ratio and fidelity.