For most purposes, the vacuum tube has been replaced by the much smaller and less expensive transistor, either as a discrete device or in an integrated circuit.
and Canadian English) or (thermionic) valve (outside North America) is a device generally used to amplify, or otherwise modify, a signal by controlling the movement of electrons in an evacuated space.
Although the envelope was classically glass, power tubes often use ceramic and metal.This is only a very brief overview and we suggest consulting additional resources if you are interested in additional information. Most good guitar amplifiers use tubes rather than solid-state components. The amplifier is a critical element in achieving the sound the musician desires. Tube amps are warmer, richer and have a more desirable tone than solid-state amps.The distortion and speaker-damping characteristics of a tube amp with an output transformer matched to the speaker load is hard to replicate with solid-state devices.Tube amps are particularly popular with serious musicians.Many musicians prefer to play vintage Fender, Marshall and Gibson amps.