Korg SAS-20 (1983)

The SAS-20 is one of those Korgs that almost slipped through the cracks. It's a home/personal keyboard from the early '80s. The Electronic Soundmaker advertisement from September 1983 files it under "Keyboard - Home/Personal," and that's about the firmest thing anyone has written down about it. A Mix magazine studio directory from May 1987 (p.136) lists the Danbury Electronic Recording Studio with its noise-reduction gear, which gives a rough idea of the small studio setting these instruments turned up in. It appears to be Korg's first arranger keyboard. The pitch was a built-in computer that analyzed the melody you played and generated accompaniment underneath it. That's a notable "first" for the company, and it survives mainly in demo videos and collector chatter rather than in any official history.

The service manual is the best source we have, and it fills in a lot of what the catalog listings leave blank. The keyboard is 61 keys, split so the lower 19 handle accompaniment and the upper 42 are for melody. The instrument voices are a very 1983 list: piano, strings, organ, flute, electric piano, vibraphone, harpsichord, brass ensemble, jazz organ, clarinet, jazz guitar, and clavi-synth. The auto-accompaniment runs sixteen patterns — two beat, ballad I and II, country, bossa nova, rock I through IV, shuffle, disco, 3 beat, bluegrass, Latin, R&B, and jazz — with a one-bar fill for each. There's a "Compu Magic" accompaniment section with major I/II and minor I/II selectors, plus melody chord, sustain, and stereo effects. The chorus circuit is a BBD (bucket-brigade) design, and the amp drives a pair of 12 cm, 4-ohm, 7-watt speakers. Mic input is 1 MΩ with a 2–90 mV range; line out is 2.5 Vp-p max; the headphone output is 75 Ω at 100 mW into 600 Ω. Master tune is ±50 cents, transpose spans Db–F# major in twelve steps, and tempo runs from 40 to 240 BPM. The whole thing is built around a set of KLM-series boards (KLM-455 power/chorus/amp, KLM-456, KLM-459 for the switch/LED and filter logic), and there's a ROM pack holder on the case — an expansion cartridge slot, which explains why surviving units turn up with cartridge adapters.

Beyond that, the record gets thin and contradictory. Sellers title these "1984" units and the 1983 ad is solid, but one database claims a late-1990s release. That doesn't square with the BBD chorus, the 61-key split, or the ad date, so treat the late-'90s claim with suspicion. There's also a claim of "16-voice polyphonic, 16-bit sampler, 16-track sequencer" floating around, but it comes from a single aggregator source and doesn't match anything in the service manual, so the Archive won't assert it. No original retail price, no weight, no dimensions, and no period reviews have surfaced. What does exist is a small aftermarket for "Factory OS EPROM rescue" firmware. That tells you the OS lives on a socketed EPROM and that dead units are common enough to support a repair trade. A Reverb listing in Portugal had one at €150 before it ended. US eBay asking prices have run from about $214 up to the high $200s for complete examples with cover and papers. One YouTube description credits the SAS-20 with the drum pattern, bass, and the horn at the end of a Philip Glass-adjacent recording.

Known specs:

Introduced: 1983 (per Electronic Soundmaker ad, September 1983)
Type: home/personal arranger keyboard — Korg's first
Keyboard: 61 keys, lower 19 accompaniment / upper 42 melody
Voices: piano, strings, organ, flute, electric piano, vibraphone, harpsichord, brass ensemble, jazz organ, clarinet, jazz guitar, clavi-synth
Accompaniment: 16 patterns, one-bar fill each
Effects: melody chord, sustain, stereo (BBD chorus)
Speakers: 2 × 12 cm, 4 Ω, 7 W
Power: AC or 12V DC (car adapter)
Expansion: ROM pack cartridge slot