Preamp

The first stage of an amplifier's signal path, which raises the instrument's small signal to a usable level and shapes its tone before the power stage.

In most designs it is also where distortion begins, since the gain control determines how hard the following stages are driven, and its tone stack sets the frequency balance that the power section then works on. A preamp can exist independently, as a pedal or a rack unit feeding a separate power amplifier, which is how players mix and match voicings and output stages. Its design, particularly the number and type of valves or transistors, largely defines an amplifier's character.

Example: sending a dedicated preamp into a power amp and cabinet lets a player keep a familiar tone while choosing a lighter power section.

Preamp

See also