and amplifies it through a power amplifier; it is then projected through loudspeakers. When the preamp and power amp circuits are combined with one or more loudspeakers in a single enclosure, it is known as a combo. When the preamp and power amp are housed together for use with an external speaker cabinet, it is known as a head.

There is a wide range of sizes and power ratings for guitar amplifiers, from small, low-wattage