Also found in: Wikipedia.
microphone preampAn electronic circuit or stand-alone device that boosts microphone input. A mic preamp is used to adjust the volume of the signal sent to powered speakers or an amplifier. Unlike a phono preamp, there is no standard equalization stage, although there may be a gain control to balance different inputs to the same level. See phono preamp.
|Single-Channel Mic Preamp|
|Because microphones have different output levels, the GAIN dial is used to balance various inputs so that the OUTPUT volume will always be the same. At the very left is a high impedance (Hi-Z) input port, typically for a guitar or bass instrument. (Image courtesy of Warm Audio LLC, www.warmaudio.com)|