This Kawai K5m Synthesiser Module is in great working order, and comes complete with its original box. Here's a quick spec...
 
Kawai K5m Synthesizer Module
The Kawai K5m Synthesizer Module is a powerful and uniquely expressive digital instrument from the late 1980s, offering real‑time additive synthesis in a rack‑mount format. Released in 1987, the K5m delivers the full sound engine of the Kawai K5 keyboard synthesizer, bringing deep harmonic control and advanced multitimbral performance to professional MIDI studios. 
True Additive Synthesis Engine: Construct sounds by controlling the levels of up to 126 individual sine‑wave harmonics, allowing unparalleled precision in shaping complex digital timbres, evolving textures, and experimental soundscapes.
Dual Harmonic Generators: Features paired harmonic sets that can be layered, detuned, or assigned independently, enabling rich ensembles, animated pads, and highly detailed tonal movement. 
Extensive Envelope Control: Each harmonic group is shaped by multi‑stage envelopes, alongside dedicated envelopes for pitch, filter, and amplifier stages—delivering an unusually high level of articulation for a digital synthesiser of its era. 
Dynamic Digital Filtering: Includes digital resonant low‑pass filters and an 11‑band digital formant filter, allowing subtractive shaping and spectral sculpting after harmonic construction. 
16‑Voice Polyphony & 15‑Part Multitimbrality: Designed for advanced MIDI setups, the K5m supports complex splits, layers, and multi‑channel sequencing across its internal architecture. 
Flexible Studio Outputs: Provides four assignable individual outputs plus a stereo mix output, making it ideal for detailed mixing, processing, and live performance routing. 
Legendary Sound & Heritage: Known for its shimmering digital pads, evolving textures, and crystalline harmonic tones, the K5m has been used by notable artists including Jean‑Michel Jarre and Jan Hammer, and remains highly regarded among sound designers and collectors. 
Professional Rack‑Mount Design: Housed in a robust 4U rack chassis with full MIDI In/Out/Thru support, external memory card expansion, and comprehensive system control for serious studio integration.
 
Whether you’re exploring advanced additive synthesis, expanding a vintage MIDI rack, or searching for a digital instrument with truly unique sonic capabilities, the Kawai K5m Synthesizer Module stands as one of the most ambitious and distinctive synthesisers of its time.