The term "Microphone preamplifier" is used to describe an amplifier designed specifically to accept microphone inputs and increase the signal level to Line level. The term "MicPre" is used interchangeably with Microphone Preamplifier.
A Microphone preamplifier can either be a "stand-alone" unit that provides an input or multiple inputs for microphones and corresponding Line level outputs; or can be integrated into other equipment such as a "channel strip" of a multi-track console or desktop mixer, rack mounted multi-function units, or "lunch box" units that house modules in the form used in multi-track consoles.
For good performance; the inputs are balanced and optimized for low-impedance microphones typically used in professional applications, which have a source impedance in the range of 50-600 Ohms. In some instances, input impedance settings are available to better match Ribbon microphone impedance. Some form of adjustable gain is usually provided to allow for variations in both microphone output level and acoustic source level. Gain in the range of 20-65dB is common; with higher levels of gain only available in very low-noise designs. Balanced line-level outputs are typical of "stand-alone" MicPre units.