The Head (hɛ́d) of an amplifier refers to a stand-alone portion of a guitar amplifier setup, which contains the pre-amp and power amplifier sections, but not speakers. An electric guitar is plugged into the wood or metal-enclosed head, which in turn is plugged into the speaker cabinet. The head is responsible for the pre-amp stage of the guitar signal, which usually contains controls for gain and tone, which then feeds into the power amp stage, which is responsible for volume output to the speakers.

The head is usually placed above one or two stacked speaker cabinets. This configuration is referred to as a “half-stack” or “stack,” as opposed to a “combo” amplifier which contains the pre- and post-amp, including a speaker(s), within a single cabinet.