What it is and what it was built for
It is a series of analog music synthesizers produced from 1975 to 1979. It was built to play chords — the first production synthesizers capable of doing so.
How it works, in terms a player would use
It uses multiple SEM modules — each generating one voice — under shared keyboard control. A digitally scanned keyboard routes notes to active SEMs. A two-channel sequencer records and plays back patterns.
What it does better than anything else
It delivers unmatched chordal thickness and depth from random variance between discrete analog SEMs — a trait no later polyphonic synth replicates identically.
What it does badly
It offers no voice allocation logic beyond fixed assignment. It has no patch memory. Tuning drifts across SEMs. Maintenance is costly and parts are rare.
What people made with it
Musicians used it to create layered, evolving pads and basslines that breathe with instability — textures defined by SEM-to-SEM inconsistency, not precision.
Who should use it, and who should not
Use it if you work with hands-on, performance-driven analog synthesis and accept tuning instability as part of the voice. Do not use it if you rely on recallable patches or stable intonation.
Is it worth your time
Yes, if you need chordal analog synthesis with organic variation between voices. No, if you need reliability, patch memory, or modern workflow integration.