Clavioline

Clavioline circuit diagrams (U.S. patent 2,563,477)

Fig.1 Oscillator and keyboard

Fig.2 Vibrato effect

Fig.3 Filter assembly

The clavioline is an electronic analog synthesizer. It was invented by French engineer Constant Martin in 1947 in Versailles.^[1][2]

The instrument consists of a keyboard and a separate amplifier and speaker unit. The keyboard usually covered three octaves,^[3] and had a number of switches to alter the tone of the sound produced, add vibrato (a defining feature of the instrument),^[1] 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 aided in creating the instrument's signature tones, by deliberately providing a large amount of distortion.^[1]

Several models of the Clavioline were produced by different companies. Among the more important were the Standard, Reverb, and Concert models by Selmer in France^[3] and Gibson in the United States^[4] in the 1950s. The six-octave model employing octave transposition was developed by Harald Bode^[5] and manufactured under license by Jörgensen Electronic in Germany.^[6] In England, the Jennings Organ Company's first successful product was the Univox, an early self-powered electronic keyboard inspired by the Selmer Clavioline.^[7] In Japan, Ace Tone's first prototype, the Canary S-2 (1962), was based on the Clavioline.^[8]