Ensoniq SD-1/32 (1990)
The last keyboard workstation Ensoniq ever built - 32 voices of 24-bit DSP power that the market barely noticed.
Overview
The Ensoniq SD-1/32 arrived in 1990 at a U.S. list price of $2,195. It had 32-voice polyphony and a 24-bit DSP engine that, on paper, outclassed nearly everything in its lane. It was the direct successor to the SD-1 and shared that instrument's sound engine, but with expanded memory: 180 internal patches, 40 internal presets, and 20 internal drum kits, with room for 40 more patches and 10 more drum kits on card. It was the most ambitious keyboard workstation Ensoniq ever shipped. It was also the last.
The SD-1/32 was the final keyboard workstation from Ensoniq. It's a complete music production station: a 16-track sequencer that stores 24 songs and 12,000 notes, a 24-bit effects section with 40 configurations, and drum machine-style functionality, all in one 61-key package. Owners describe it as essentially the keyboard version of the EPS sampler - same architecture, same philosophy - but with a synth engine instead of sampling. The chassis weighs 30 pounds, and the 80 waveforms inside give the sound designer real material to work with.
The SD-1/32 was a good workstation, not a great one. The sound was described as good but not great, and the presets were considered mediocre out of the box. Sequencing is where it excelled. Owners consistently praise the sequencer as powerful and call the SD-1/32 a great machine for sequencing. The polyphony and effects drew praise too, and at $2,195 it was considered a good value for the money.
Key Features
32-Voice Polyphony with 24-bit DSP
The headline spec is the 32-voice polyphony, which made the SD-1/32 three times more powerful than Ensoniq's earlier ESQ-1 and SQ-80 in raw voice count. It comes from a 24-bit DSP engine that handles both sound generation and effects processing. You can layer complex patches, run the 16-track sequencer, and still not run out of voices mid-song, which earlier Ensoniq players couldn't count on. The 24-bit effects section offers 40 configurations, so the internal processing has serious range without outboard gear. The ASR-10's 24-bit digital effects processor had 50 algorithms, and the SD-1/32's effects were similarly capable (EQ Magazine, February 1993, p.64).
Three LFOs, Three Envelopes, Two Filter Types
For a workstation aimed at sequencing and production, the SD-1/32 still has respectable synthesis depth. Three LFOs and three envelopes per voice give you real modulation flexibility, and two filter types let you shape the 80 waveforms. Those waveforms are a solid palette, even if the factory presets don't always show them in the best light.
16-Track Sequencer with 12,000-Note Storage
The sequencer is where the SD-1/32 earns its keep. Sixteen tracks, 24 songs, and 12,000 notes of storage made it a serious composition tool in 1990, and owners still praise it today. Sequencing, effects, and drum kits (20 internal, 10 more on card) work together, so you could build a complete arrangement without leaving the keyboard. Many players kept their SD-1/32 long after the presets had worn thin. The built-in 3.5-inch floppy disk drive handled storage, though that drive would become a common failure point decades later.
Historical Context
The SD-1/32 was introduced in 1990 as the successor to the SD-1, which itself was Ensoniq's follow-up to the ESQ-1 and SQ-80. It went up directly against the Korg M1 and the Yamaha SY77. The M1 was king when the SD-1/32 hit the market, and Ensoniq's almost nonexistent distribution meant the SD-1/32 never got the chance to fight for its share. Sales were poor, and the SD-1/32 went down as the last of the keyboard workstations from Ensoniq.
The SD-1/32 was arguably the most complete package Ensoniq had ever assembled. It combined 32-voice polyphony, a powerful 16-track sequencer, 24-bit effects, and drum machine functionality in one all-in-one production station.
Collectibility & Value
Current prices for the SD-1/32 range from $300 to $600, which makes it one of the more affordable ways into serious vintage workstation territory. At that price it's a bargain for sequencing work. The sequencer is powerful, and the 32-voice polyphony with 24-bit effects holds up well. The presets are mediocre, so plan on some time for sound design.
Common problems include a dead internal battery, which needs replacement to retain patches, and faulty keys. The floppy drive is also a frequent failure point, and spare parts are getting hard to find. If you're buying sight unseen, budget for at least a battery swap and possibly a key contact cleaning. The core electronics are generally reliable. The wear items are the usual suspects: battery, keys, floppy drive. The condition of the keybed and the drive mechanism should be your main negotiation points.
Similar items on eBay
No exact Ensoniq SD-1/32 listings are live right now — these searches show current Ensoniq and similar vintage synth gear on eBay:
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.