Wiktionary
n. An electronic musical instrument with a keyboard and a separate amplifier and speaker unit, a forerunner to the analog synthesizer.
Wikipedia
The clavioline is an electronic keyboard instrument, a forerunner to the analog synthesizer.
It was invented by Constant Martin in 1947 in Versailles. It consists of a keyboard and a separate amplifier and speaker unit. The keyboard usually covered three octaves, and had a number of switches to alter the tone of the sound produced, add vibrato, .
and provide other effects. The Clavioline used a vacuum tube oscillator to produce a buzzy waveform, almost a square wave, which could then be altered using high-pass and low-pass filtering, as well as the vibrato. The amplifier also deliberately provided a large amount of distortion. .
Several models were produced by different companies; among the more important were the Standard, Reverb, and Concert models by Selmer in France
and Gibson in the United States
in the 1950s. The 6-octave model employing octave transposition was developed by Harald Bode, and under licensed by Jörgensen Electronic in Germany.
In England the Jennings Organ Company's first successful product was the Univox, an early self-powered electronic keyboard inspired by the Selmer Clavioline.
Also in Japan, Ace Tone's first prototype, Canary S-2 (1962) was designed based on Clavioline.