Developer Joe Landers has released Profligacy, a free and open-source emulation of the Korg Prophecy synthesizer for macOS and Windows.
This one is definitely rough around the edges, but it is worth your attention if you’re into classic 90s synth sounds. Profligacy emulates the original Prophecy hardware at a low level and runs the instrument’s firmware.
The Korg Prophecy arrived in 1995 as a monophonic synthesizer built around the company’s MOSS synthesis system. It combines virtual analog and physical modeling techniques, with oscillator models covering analog-style waves, noise and comb filtering, variable phase modulation, cross/ring modulation, and modeled instruments.
Profligacy emulates the Prophecy’s NEC V55PI and Hitachi H8/3003 processors, along with its three TI TMS57002 DSP chips. The dev has spent months probing communication between the chips and comparing the emulated DSP output with the original hardware.
The post-DAC analog output stage is not modeled, but the digital path is definitely the main attraction here anyway. The current alpha also exposes the complete factory program list to compatible hosts and lets you automate several performance controls, including the wheels and X/Y/Z controls.
The short demo below features Profligacy playing a couple of patches we all recognize from The Prodigy’s The Fat of the Land.
There is one major requirement: Profligacy does not include the copyrighted Korg firmware. On first launch, you must point it to a folder containing korgprop/ic12_v17.bin and korgprop/ic22_v17.bin, or a korgprop.zip archive containing those files.
The developer cannot provide the firmware, and the project is intended for people who already own the original hardware and firmware. This is similar to the setup required by the recent Vintage Emulator Studio project and hardware-level emulations from The Usual Suspects, such as OsTIrus and Xenia.
The current release is Profligacy 1.0.0 alpha 8. The macOS version requires Apple Silicon and macOS 15 or newer, with AU, VST3, and standalone formats. Windows users get an experimental 64-bit VST3 and standalone preview.
Installation is also less polished than a typical plugin. The bundles are copied manually, the macOS build is not notarized, and the Windows preview is unsigned. Only one Profligacy engine can run inside a host process, so additional instances remain inactive.
In other words, this is not yet the Prophecy emulation I would trust in a critical project. However, it is a pretty cool technical preview for anyone interested in the original instrument, provided you have legitimate firmware dumps and do not mind some setup work.
Profligacy is released under the AGPLv3 license. The plugin packages, source code, checksums, and detailed installation notes are available on GitHub without an account.
Download: Profligacy (FREE)
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Last Updated on September 16, 2026 by Tomislav Zlatic.
