UNSTABLE Logo

expressive · emotional · evocative

Inspired by the pinnacle of analog synthesizers, UNSTABLE takes on the legendary Yamaha CS-80 — and gets closer to the real hardware than anything else out there. Soulful, organic, and with a mind of its own!

UNSTABLE Synthesizer Interface

UNSTABLE SYNTH

A modern go at the famous Yamaha CS-80 Synthesizer.

ANALOG OSCILLATORS

UNSTABLE features two synthesis layers, each offering a noise, sawtooth, and pulse wave oscillator, with adjustable pulse width and variable speed pulse width modulation. Unlike the Yamaha CS-80, the level of each oscillator is adjustable, allowing for free mixing of the waveforms, which are closely modelled after the original.

Waveform comparison: real CS-80 vs UNSTABLE

Waveform comparison across octaves: real Yamaha CS-80 (grey) vs UNSTABLE (purple)

FILTERS

The CS-80 features two state-variable filters in series, which allow for a unique subtractive sound synthesis, unlike most common synthesizers. In UNSTABLE, the high-pass filter is modelled after the original; I put a little more beef into the low-pass filter, however, providing a vaster range of musical harmonics.

RING MODULATOR

The Yamaha CS-80 features the most musical ring modulator ever built, and I did our best to model it as closely as possible, with its own analog-style attack and decay envelope modifying the modulation speed.

RIBBON CONTROLLER

Use the innovative on screen ribbon controller to pitch bend your sound up to an octave.

POLY PRESSURE

UNSTABLE supports full polyphonic aftertouch, just as the original hardware did.

ARPEGGIATOR

UNSTABLE features a sophisticated 16 step arpeggiator with variable note and modulation values.

ANALOG DRIVE

A dedicated drive circuit adds analog warmth and subtle harmonic distortion for loudness and crisp presence that cuts through your mix without sacrificing dynamics.

EFFECTS

UNSTABLE features the popular effect engines of DarkStar Reverb and Delay, as well as the luscious WingMen Chorus, to bring your sound to the next level. Imagine a CS-80 with something along the JUNO-60 Chorus and Blackhole reverb.

Audio Demos

All demos are UNSTABLE only, no external effects!

Ring Modulator

Blade Runner Lead

Soft Bells

CS-80 Guitar

Pulsed Organ

Smooth Mover Arp

System Requirements

Operating Systems

MAC:
macOS Ventura (13.6) or higher
(Apple silicon Macs supported)
64-bit only

PC:
Windows 10 or 11
64-bit only

Plugin Formats

VST3 (PC/MAC), AU (Mac only)

Screen Resolution

Recommended minimum screen resolution is 1920x1080 pixels.
Plugin size is 1580x900 at 100%. GUI zoomable from 50% to 200%.

Made with FAUST

TRY UNSTABLE — FREE

UNSTABLE is fully functional for 10 minutes per session — no features removed, no watermarks. Load it up, play it, and hear what it can do. When you're ready, unlock unlimited use with a license.

Current version: v1.1

Please note updating from v1.0.12 or earlier requires redialing the LPF in your saved presets, as LPF envelope mapping was moved to hardware accurate exponential octave domain

FACTORY PRESETS

To download the factory presets click the button below and put them into the preset folder. You can get to the preset folder by clicking on the top left button "MORE" in the preset browser. Have fun!

Download Factory Presets

LICENSING

Enjoyed the trial? License codes are available on Patreon and Gumroad.

FREE PROMOTIONAL LICENSE

If you are running a decent YouTube Channel and looking to review the plugin, I may be able to provide a free license. Please contact me at morphoice@gmail.com with your channel details and review proposal.

LATEST CHANGES

v1.1
- Greatly improved physical model of the original Yamaha CS-80 oscillator voice cards, including nonlinearities and instabilities, based on intensive measurements of the original hardware.

v1.0.15
- New highly improved DarkStar Reverb / Delay engine
- New Chorus engine
- Fixed an issue where arpeggiator time would not change
- Fixed an issue where LFO would not control VCA

v1.0.14
- Fixed an issue where SIN oscillator would blip when turned to zero
- Fixed an issue where SIN oscillator wouldn't react to Initial Pitch Bend
- Fixed an issue where VCA Level Slider would not workflow
- Added Compressor Dials to Effect section

v1.0.13
- Fixed LPF envelope mapping to be hardware accurate exponential octave domain, filter envelope sweeps are more musical, but existing presets will sound darker at mid filter settings and may need their LPF level/envelope re-dialed.
- Fixed an issue where the sustain pedal would behave weird
- Minor bugfixes

v1.0.12
- Fixed pitch bend

v1.0.11
- Added polyphonic aftertouch

CONTRIBUTE PRESETS

If you wish to contribute presets please feel free to send them to morphoice@gmail.com. I am happy to have a listen and add them to the factory content if suitable.