SD-1 [32-voice ver.] © 1991 Ensoniq
The Ensoniq SD-1/32, released as an expanded version of the SD-1, is a high-end music production workstation based on Ensoniq’s Transwave wavetable synthesis engine. It increases polyphony from 21 to 32 voices while retaining the same deep synthesis architecture, sequencer, and effects system. The instrument combines multi-oscillator wavetable synthesis, dual digital filters, a powerful 24-track sequencer, and integrated effects, making it a full all-in-one production workstation aimed at professional studio and performance use.
61-key keyboard (velocity + polyphonic aftertouch)
12-part multitimbrality
3.5" floppy disk storage
Built-in digital effects processor
MIDI In / Out / Thru
Split/layer performance modes
Deep voice stacking (very dense sounds possible)
Many SD-1 units were later upgraded from 21 ? 32 voices via hardware board revision.
Despite being called “32-voice,” polyphony is dynamic and voice-stacked, meaning complex patches reduce available voices.
The SD-1/32 is often considered the final “pure VFX lineage” machine before the Fizmo era.
It shares a strong design philosophy with the ESQ-1 and SQ-80 but with far more modulation depth.
It remains popular in modern electronic music due to its distinctive wavetable character.