The first simple form of a vacuum tube (diode) was invented in 1904 by J. A. Fleming. In the first half of the twentieth century, vacuum tubes became an important part of electronic circuits. Vacuum tubes were critical to the development of radio, television, radar, sound recording and reproduction, long-distance telephone networks, and even to the development of analog and early digital computers. It was the invention of the vacuum tube that made these technologies widespread and practical, creating the discipline of electronics. Up to and including the 1970s, countless types of vacuum tubes were developed and produced by manufacturers all over the world. A number of manufacturers of vacuum tubes that are (or have been) of particular importance to the audio world will be highlighted in a separate web page. These are:
- Philips and a number of linked manufacturers
Enough people prefer tube sound to make tube amplifiers commercially viable in three areas: musical instrument (e.g., guitar) amplifiers, devices used in recording studios, and audio[hile equipment.
Guitarists prefer using valve amplifiers to solid-state models, often due to the way they tend to distort when overdriven. Any amplifier can only accurately amplify a signal to a certain volume; past this limit, the amplifier will begin to distort the signal. Different circuits will distort the signal in different ways; some guitarists prefer the distortion characteristics of vacuum tubes. Most popular vintage models use vacuum tubes.