SD-1 [21-voice ver.] © 1990 Ensoniq.
The Ensoniq SD-1 was a flagship music production workstation combining advanced wavetable synthesis (Transwave technology), a powerful multitimbral engine, and a full onboard sequencer. Built by Ensoniq, it evolved from the VFX/VFX-SD architecture and introduced improved ROM waveforms, enhanced effects processing, and deeper modulation capabilities. The SD-1 was designed as an all-in-one production instrument capable of sound design, sequencing, and performance without external gear.
61-key keyboard (velocity + poly aftertouch)
12-part multitimbrality
Built-in 24-bit multi-effects (reverb, delay, chorus, flanger)
3.5" floppy disk storage
MIDI In/Out/Thru
Studio-grade stereo outputs
Layered “voice stacking” architecture
The SD-1 evolved directly from the VFX-SD, sharing much of its architecture.
Ensoniq’s “voice stacking” system allows extremely thick patches at the cost of polyphony.
It is famous for a distinct “warm + slightly gritty digital” character.
The SD-1 helped establish the foundation for the later Ensoniq Fizmo sound.
Many users still consider it one of the most “musical” digital workstations of its era.
The SD-1/32 upgrade was not just firmware—it often required hardware changes (board revisions).