An archtop guitar is a steel-stringed electric (semi-acoustic) guitar with a arched top, popular with jazz players.
Modern archtop guitars was originally built by Gibson, that has specialized in producing mandolin with arched top for a many years, when Lloyd Loar designed their archetypal accoustic Gibson L5 in 1922, with f-holes as a big band rhythm guitar made to cut through.
The acoustic qualities of an archtop is a tradeoff between that and amplified feedback. Several factors determines the acoustic qualities of an archtop.
- Depth and size of the body
- Carved top - superior acoustic tone, but expensive and most feedback.
- Solid top, not carved - two or three layers of selected spuce or sedar boards is pressed together. Has a warm soft accoustic tone with. Less feedback.
- Plywood with a thin veneer like a laminboard. Least expensive and least feedback.
- Floating pickup
- Thickness of the top
- On semi-hollow archtops, that has a center block or a solid core with hollowed out bouts (Gibson ES-335), feedback is less of a problem.
In these, the bridge is fixed to a solid block of wood rather than to a sounding board, and the belly vibration is minimised much as in a solid body instrument.
Thin-bodied semi-acoustic instruments, such as the Epiphone Casino. These possess both a sounding board and sound box, but the function of these is purely to modify the sound transmitted to the pickups. Such guitars are still intended purely as electric instruments, and while they do make some sound when the pickups are not used, the tone is weak and not normally considered musically useful.
Full hollowbody semi-acoustic instruments,