What is the function of Pre-Out port in an AV Receiver?

Pre-out stands for preamplification output. As the name suggests, it is a parallel output made available before the signal is amplified to be reproduced by the loudspeaker. Pre-out is a volume-controlled, source-selected analogue audio output. In a conventional receiver, it helps the signal pass through and later be amplified by another power source. Functions like source selection, volume control, DSP and other effects are controlled by the receiver, the power amplifier just drives the speakers. Pre-out is where you connect an external power amplifier in place of the built-in one integrated in the receiver.

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