A preamplifier (preamp), or control amp in some parts of the world,'s an electronic amplifier which precedes another amplifier to prepare an electronic signal for further amplification or processing. The preamplifier circuitry may or may not be housed as a separate component. Description In general, the function of a preamp's to amplify a low-level signal to line-level. A list of common low-level signal sources would include a pickup, microphone, turntable or other transducer. Equalization an… (More on Preamplifier)