Keio Gijutsu Donca Matic DE-20 Analog Drum Machine

1963 saw the launch of the Donca Matic DA-20 from Keio (later Korg), the first drum machine from Keio. It was designed for solo entertainers with keyboards who couldn't afford or didn't want a drummer. It was more comprehensively equipped than Wurlitzer's competitor, the Sideman, which had been on the market since 1959. In 1966, Keio launched the Donca Matic DE-20 as a smaller and lighter version.

The Donca Matic DE-20 uses tube circuits for the sounds and mechanical wheels for the rhythm patterns. As with the Wurlitzer Sideman, an electric motor drives a rotating arm fitted with spring contacts. This scans a Pertinax plate with circles of soldered contact points. When the spring touches a contact, a drum sound is triggered. The rhythms are created by the arrangement of the contact points on the carrier plate. The device has an internal tube amplifier and a loudspeaker. 
The 20 rhythm presets are combined in pairs: Foxtrot / Swing, Rock 1 / Rock 2, Rock 3 / Rock 4, Ballad / Western, Bossanova 1 / Bossanova 2, Tango / Habanera, Rumba / Beguine, Mambo / Chacha, Samba / Baion, Waltz 2 / Waltz 2. Switches can be used to activate bass drum, snare drum or claves. Cymbal / Brush, Snare Drum / Bass Drum, Volume, Tone and Tempo can be changed. A metronome can also be activated.