- Sarah Davachi
Electromechanical keyboard instrument designed in 1974 by Dave Biro of Yalesville, Connecticut, and patented on 2 June 1975. Between 1975 and 1977, Birotronics Ltd in High Wycombe, Buckinghamshire, manufactured the instrument in very limited quantities with the funding of the Yes keyboardist Rick Wakeman. Like the Mellotron and Chamberlin instruments, the Birotron uses a tape-replay mechanism to play magnetic-tape loops of pre-recorded sound. However, unlike the Mellotron—which was capable of sustaining a sample for only about eight seconds—the Birotron uses tape cartridges that enable it to maintain continuous sound indefinitely. Each cartridge contains eight separate tape tracks in parallel and is split into four different sounds; therefore, each cartridge spans two notes on the keyboard. To cope with the bleeding of sound that occasionally occurs between adjacent tape tracks, Biro designed the instrument in such a way that the two pitches corresponding to one cartridge are separated by the interval of a fifth. That way, in the event of bleeding between tracks, the resulting sound is consonant. The Birotron also features attack and delay controls. Similar in function to the VCA envelope of analogue synthesizers, these controls allow imitation of the natural attack and decay characteristics of the sampled instruments. Additionally, cartridges can be interchanged in order to split and layer a multitude of sounds across the keyboard....