A vacuum tube relies on thermionic emission, usually from a heated filament, to release electrons that travel through a vacuum to an anode. By placing control grids in the electron path, the tube can amplify signals, rectify alternating current, or act as a switch. Though largely replaced by solid-state transistors, they remain in use for high-power RF transmitters, specialized audio equipment, and cathode ray displays.
Let the amplifier warm up for a minute so the vacuum tube heaters can reach operating temperature.
Also heard as
- tube
- valve
- electron tube
Related terms
Valve amplifier
An electronic amplifier that uses vacuum tubes instead of transistors to boost a signal.
Triode
A three-electrode vacuum tube capable of amplifying electronic signals.
Cathode ray tube
A vacuum tube containing one or more electron guns and a phosphorescent screen used to display images.
Solid-state
Built entirely from semiconductor materials without moving parts or vacuum gaps.