Meaning of preamplifier

pre•am•pli•fi•er

Pronunciation: (prē-am'plu-fī"ur), [key]
— n.
  1. a device in the amplifier circuit of a radio or phonograph that increases the strength of a weak signal for detection and further amplification.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.