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Spektra-5000

The first software recreation of the Kawai K5000 advanced additive synthesizer. 64 harmonics per source. Six sources. Spectral MORF morphing. A 128-band formant filter. And a librarian for your real K5000 hardware.

$79 · VST3 · CLAP · Standalone · Windows · No subscriptions

Harmonic Spectrum — ADD Source A

Odd harmonics, decaying — classic pipe organ

What is it?

The K5000 was the most ambitious
additive synth ever built.

Released in 1996, the Kawai K5000 gave each note its own 64-harmonic spectrum with independent envelopes — every partial could grow, shrink, and evolve independently over time. It produced sounds no subtractive synth could touch: impossibly rich strings, evolving bells, vocal-like pads. Then Kawai discontinued it, and nobody rebuilt it.

Until now. Spektra-5000 faithfully recreates the entire K5000 additive engine in software — and extends it with MORF spectral morphing, a 128-band formant filter, and 32-voice polyphony.

Features

Everything the K5000 had.
Plus what it should have had.

64-Harmonic Additive Engine

Each note has its own 64-harmonic spectrum with soft and loud envelopes, giving every partial independent control over time. Six ADD sources per patch, each with a completely different spectrum.

MORF Spectral Morphing

Morph between two complete harmonic spectra in real time — interpolate every partial independently. Sounds no subtractive filter can produce: bells that become strings, organs that breathe.

128-Band Formant Filter

A 128-band vocoder-quality formant filter that sculpts the harmonic content into vocal shapes, vowel motions, and resonant body tones — the K5000's signature sound-design tool, fully implemented.

All 37 Effect Types

Every effect from the original K5000 — chorus, delay, reverb, distortion, EQ, rotary, compressor, and 30 more — faithfully recreated and chainable. Plus modern improvements where the originals had aliasing or noise.

K5000 Bank Import

Load your existing K5000 sound banks directly — .KAA, .KA1, and .SYX SysEx formats. Your 25-year-old patches load and sound exactly as they did on the hardware. Export back to .KA1 for hardware round-tripping.

32-Voice Polyphony

The original K5000 managed 16 voices, taxed. Spektra-5000 delivers 32 voices of full additive synthesis on a modern CPU — enough for dense pads and layered performances without voice stealing.

Hardware Integration

Your K5000 patches, loaded.

If you've been maintaining K5000 sound banks for decades, Spektra-5000 doesn't ask you to start over. It reads the original binary formats directly.

  • .KAA / .KA1 file import — load Kawai's native patch and bank dumps
  • .SYX SysEx import — bulk-dump from the hardware via MIDI
  • .KA1 export — send patches back to the hardware
  • Librarian mode — organize, audition, and transfer banks
.KAA.KA1.SYX
SysEx Transfer — K5000 ↔ Spektra-5000
K5000
Hardware
Spektra-5000
Plugin

Full bidirectional SysEx transfer · tested with 403 Kawai bank files

Factory Library

55 original presets.

Every preset was designed from scratch using Spektra-5000's additive engine — not ported, not converted. 48 hand-crafted factory presets: evolving pads, glassy bells, rich organs, vocal textures, and sounds that don't have a category yet.

Cathedral Glass
Pad
Resonant Bloom
Pad
Midnight Bell
Bell
Vocal Whisper
Formant
Pulse Organ
Organ
Spectral Strings
Strings
MORF Sequence
Motion
Harmonic Rain
Texture
Crystal Reed
Lead
Deep Resonance
Bass
Aurora Drift
Pad
Phase Vowel
Formant

+ 43 more · Plus a built-in preset generator for endless variation

Technical Specs

The details.

SynthesisAdditive — 64 harmonics per ADD source, 6 sources per patch, per-harmonic envelopes (soft + loud)
MORFSpectral morphing — real-time interpolation between two complete 64-harmonic spectra
Formant Filter128-band vocoder-quality formant filter with vowel/resonance shaping
EffectsAll 37 K5000 effect types — chorus, delay, reverb, distortion, EQ, rotary, compressor, and more
Polyphony32 voices (up from 16 on the original hardware)
ModulationLFO, AM, arpeggiator, DCF, DCA with per-source routing, velToEnv, LFO key-scaling, BP/Notch filter modes
K5000 Import.KAA, .KA1, .SYX SysEx bank import · .KA1 export · hardware librarian
Presets48 hand-crafted factory presets — curated pads, leads, basses, bells, organs, strings, FX, MORF morphing, and filtered textures
FormatsVST3, CLAP, Standalone
RequirementsWindows 10+ (64-bit, x64) — macOS and Linux builds planned, not yet shipping
BuildJUCE 8.0.13 · 6,700+ lines of C++
Pricing

Get Spektra-5000.

No subscriptions. No iLok. Buy it, own it forever.

Perpetual license — buy once, own it forever.