What is a Preamp?
A preamplifier (preamp) is an electronic amplifier which
precedes another amplifier to prepare an electronic signal for
further amplification or processing. Description In general,
the function of a preamp is to amplify a low level signal (possibly
at high impedance) to line-level. A list of common sources would
include a pickup, microphone, turntable or other transducer.
Equalization and tone control may also be applied. In a home audio
system, the term 'preamplifier' may sometimes be used to describe
equipment which merely switches between different line level
sources and applies a volume control, so that no actual
amplification may be involved. In an audio system the second
amplifier is typically a power amplifier (power amp). The
preamplifier provides voltage gain (about: 10millivolts to 1volt)
but no significant current gain. The power amplifier provides the
higher current necessary to drive loudspeakers. Preamplifiers
may be: •incorporated into the housing or chassis of the
amplifier they feed
•in a separate housing
•mounted in other pieces of equipment, such as turntables,
microphones and electric basses.
•close to the signal source, remote from the next amplifier --
eg: beside hi-fi system, then feeding into a computer in the home
office. Examples •the integrated preamplifier in a foil
•the first stages of an instrument amplifier.
•a stand-alone unit for use in live music and recording studio
•as part of a stand-alone channel strip or channel strip built
into an audio mixing desk.
•a masthead amplifier used with television receiver antenna or a
satellite receiver dish.