preamplifier - Computer Definition
(1) In the hi-fi stereo world, a preamplifier accepts signals from audio sources (CDs, turntables, etc.) and boosts the current to the level required for amplification. For details, see preamp.
(2) An electronic device that boosts signals to a certain level, which may be further amplified. Preamplifiers are used in fields such as test and measurement, optical detection and audio engineering.