Kurzweil 1000PX
A single-rack-space module that packed 120 Kurzweil 250-grade presets and 24-voice polyphony into a working musician's budget.
Overview
The 1000PX is the rack-mount expander at the head of Kurzweil's 1000 Series, a line the company built explicitly as an integrated family of "powerful, cost-effective electronic musical instruments for live performance and recording." The pitch in the manual is blunt: the 1000 Series inherits the sonic legacy of the Kurzweil 250, and identical voices played on a 250 and a 1000 Series instrument are described as "virtually indistinguishable from one another." That claim is the whole reason the 1000PX exists — it's the K250's sound library, repackaged.
The module carries 120 presets spanning Grand Piano, Strings, Choir, Organs, Acoustic Bass, Vibes, Woodwinds and Brass, and runs 24-note polyphony. For context, that polyphony figure was the top of the 1000 Series lineup: Mix (March 1988, p.131) noted in the line's own advertising that the 1000PX and K1000 offered 24 voices while the 1000SX, 1000GX and 1000HX each ran 20. The sounds are built on 16-bit floating-point digitally-sampled waveforms, and Kurzweil credits VLSI (Very Large Scale Integration) circuitry with cramming up to 120 Programs into each unit. The 1000PX is also fully multi-timbral, able to respond to all 16 MIDI channels in any combination — the spec that made it useful as the sound source in a sequencing rig rather than a single-timbre piano box.
Programming goes deeper than the preset list suggests. The 1000 Series includes both Compiled Effects — pre-programmed, adjustable treatments like Chorus, Vibrato, Tremolo and Leslie — and Modular Effects, which let the player build signal chains rather than pick from a menu. That's the difference between a rompler and something closer to a modular synth in behavior, and it's the part of the 1000 Series the manual leans on hardest when it describes the instruments as combining sample playback with "digital emulation of a traditional modular synthesizer in a single unit."
Recording Engineer (September 1988, p.79) reviewed the 1000 Series in a Hands On column, describing the 1000PX as the rack-mount version of the K1000 sampling keyboard and characterizing its sounds as "Kurzweil's greatest hits" — grand piano, orchestral strings, choir and baritone horn among them. That framing is fair and worth repeating: the 1000PX was never sold as a sound-design frontier. It was sold as the Kurzweil library, affordable, in a rack.
The 1000 Series was introduced on June 27, 1987, according to the product listing in Mix (October 1987, p.249), which described the line as making "Kurzweil 250-quality sounds" available in four rack-mount modules. The 1000PX sat alongside the 1000SX String Expander (99 presets, 20-note polyphonic), the 1000HX Horn Expander (100 presets, 20-note polyphonic) and the 1000GX Guitar Expander (20-note polyphonic), with the K1000 keyboard — 115 of the 1000PX's presets on a weighted 76-note keyboard with dual pedal switches and three 10-location programmable memory banks — as the line's only keyboard model.
Real-world use shows up in period studio inventories rather than in glossy copy. Recording Engineer documented Wendy Carlos running a 1000PX and a 1000SX alongside her Synergys and GDS Slave 32s, and composer/performer Orin using a 1000PX with a Kurzweil MidiBoard as his main controller. A player quoted in Electronic Musician kept coming back to a 1000PX rack piano across years of records specifically because it responded well to touch — the kind of endorsement no spec sheet produces.
What the record does not give is production years, original pricing, dimensions, weight, or the module's front-panel layout. Collectors chasing a 1000PX should expect a working module with the 250-derived preset library intact and should verify the effects and multi-timbral behavior on the actual unit, since none of that is documented in the available sources. What is documented is the design intent: 120 presets, 24 voices, 16-channel multi-timbral response, and a sound set Kurzweil itself claimed was indistinguishable from the 250. For a rack module from 1987, that's a specific and defensible promise.
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