Short for preamplifier. A type of amplifier specifically designed to amplify very weak signals before they are fed to subsequent gain stages or devices. Preamps are commonly used to bring things like the output of microphones up to a level where more equipment can work with the signal. Similarly, magnetic pickups (as used in guitars and basses), and phonograph cartridges are generally run through a preamp to prepare the signal to be used by other equipment downstream. Preamps are called upon to deliver extremely high amounts of gain while introducing very low amounts of noise and distortion. As such they are a critical component in the audio chain, and in recent years have come under much scrutiny by recording engineers causing many dozens of stand-alone mic preamps to be developed that allege to have superior sonic characteristics.