A Preamplifier (prí ǽmpləfɑ̀yər) is also known as a “preamp,” which is a device that takes a low level electronic signal from a guitar, boosts it and then sends the boosted signal to the amplifier. Preamplifiers are judged by how well they boost the signal strength from the an instrument, without harming the signal to noise ratio.

Pre-amps can also be used to boost the signal coming from a microphone, turntable and other audio equipment. In the past, preamplifiers accepted and passed the signals from a guitar through an analog connection. In today’s age of digital production, pre-amps are now available with use other connection technologies such as fibre, MIDI, S/PDIF and even USB.