A preamplifier, or preamp, is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and sufficient for further processing or sending to a power amplifier and loudspeaker. It is used to boost the signal strength to drive the cable to the main instrument without significantly degrading the signal-to-noise ratio (SNR) . A preamp typically offers volume controls, input switching, and may also provide tone controls or other filters. It is important to note that integrated amplifiers, receivers, amplifiers, and processors are not strictly preamps.
A preamp is not a magic bullet that will solve all audio problems, but it can let you get more out of the good audio youre already getting. It is the icing on the cake, and if the cake isnt good, even the best icing wont fix it. Preamps are used to amplify signals from analog sensors to line level. They are often integrated into the audio inputs on mixing consoles, DJ mixers, and sound cards, and can also be stand-alone devices.
When looking for a preamp, it is important to understand the differences and get the proper preamp for your setup. Specific instruments will either have a built-in preamplifier or use a separate preamp to boost their overall or specific frequency levels. For example, some acoustic instruments like guitars, violins, mandolins, or double bass will use a small device that "picks up" the pressure waves from the instrument. This signal that the pickup receives is very low, so a preamp has to be used to boost this signal.
