A preamplifier is an electronic component that is connected to a low-level signal source for providing suitable impedances and gain in an amplified signal. A singled ended preamplifier amplifies a single ended input signal by a gain factor such that the output signal is equal to the input signal multiplied by the gain factor. Differential preamplifiers are a particular type of preamplifier wherein the differential input signal comprises a positive rail component and a negative rail component. Preamplifier circuits are used in numerous applications. Typically, sound engineers use preamplifiers to amplify and process sound signals to achieve volume boosting while at the same time manipulating certain frequencies. High performance microphones require immediate preamplification of the signal generated by the microphone capsule. Microphones have low-level outputs, but microphone preamplifiers are generally designed to eliminate hum pick-up through the use of balanced-input circuitry, which electronically cancel any noise that is induced on both leads coming from the microphone. The ability of the output signal of a preamplifier circuit to faithfully reproduce the input signal is a function of many factors, including the bandwidth of the preamplifier, the frequency of the input signal, the impedance of the input system and transmission line impedance that provides the input signal, and the input impedance of the preamplifier.
Preamplifier (pre-amplifier) product listings
ITC T-6201 is a public address pre-amplifier with totally 10 inputs: 5 unbalanced MIC inputs, 3 AUX level inputs and 2 EMC (priority) level inputs. Priority muting is achieved via MIC5 and EMC 1 (secondary priority) for overriding music for paging and emergency alarms. Individual volume control for 5 each MIC inputs and 3 AUX level inputs, bass and treble for overall tone control.