A head is an amplifier unit that contains the preamp and power amp but does not include a built-in speaker. It is designed to be used with an external speaker cabinet, allowing players to choose different cabinet and speaker combinations to shape their sound.

Amp heads are popular with guitar and bass players who want flexibility and scalability, as the same head can be paired with different cabinets for home, studio, or live use. They are commonly available in valve, solid-state, and hybrid designs, and range from compact low-watt models to powerful stage-ready amplifiers.