The functions of an amp are split into two stages, preamplification and power amplification. Preamplification can be seen as ‘the part with all the knobs and switches’. It’s where you can select multiple inputs and level of gain (volume).

The second stage is where the magic really happens, where the actual amplification takes place. Gain (power) is added to the selected signal, boosting it in order to be used to power a pair of speakers, which then vibrate rapidly to produce sound.

The majority of amplifiers you will come across are called ‘integrated amplifiers’. This means that both the preamplification and power stages are contained within one unit, working together to create sound. While it’s a bit less common, preamplifiers and power amplifiers can be bought separately, and connected together via cables.

While there are pros and cons to both setups, the main idea behind keeping the two stages separate is that there is less chance of noise, keep the sensitive preamp circuitry, and the audio signals passing through, away from the electrically noisy power amplifier stage.

Now that you understand the basics of how it works, let’s look at a few other features that most amplifiers will have.