P-600-G VST3


P-600-G is a VST3 plugin designed to be used with the Prophet-600 analog synthesizer, released by Sequential Circuits in 1982. It presents all of the synthesizer’s program parameters in a single editor window within your DAW and allows for the automation of parameter changes. It also lets you store and recall programs, as well as quickly generate new sounds with the Randomize Program Settings dialog.

The Program Storage Bank window.
The Randomize Program Settings dialog.


At the moment, this plugin is only fully-functional in Reaper from Cockos (version 6 and later) and Cubase from Steinberg (version 10 and later). It is only compatible with 64-bit hosts (Windows OS only). The plugin is optimized for version SIX_0_8 of the Prophet-600’s firmware. It is not compatible with any third-party modifications to the firmware.


Simply download the .zip file below and extract the .vst3 file inside it into a folder on your computer where you store 64-bit VST3 plugins.

P-600-G Version 2.0.0 64-bit (.zip file)

There is a PDF in the download folder that explains how to set up tracks for using the plugin in Reaper and in Cubase. There is also this introductory video for using it in Reaper:

Build number 1.0.1 makes some cosmetic changes to the Randomize Program Settings dialog that are not reflected in the above video. Below is a quick demo of the revised interface:

A quick overview of the new features added to build 2.0.0:

Source Code

P-600-G was programmed in Microsoft Visual Studio 2022 using the Juce 6 Framework.
I have made my project files freely available on GitHub:


The P-600-G plugin and the code for it are provided “as is” without any warranty, and all warranties, whether expressed or implied, including merchantability and fitness for purpose, are disclaimed

The code in the Source folder of this project is open-source and you are free to use it however you see fit under the GPL v3 license. However, please credit Mister 1-2-3-4 Programming if you make use of substantial chunks of this code in your own project(s), and do not redistribute the code or the built plugin without permission. Also, if you find the plugin or code useful, please consider making a donation to support further development!

Version History

2.0.0 (latest)Interface: Double-clicking a knob control now lets you type in a new value for the parameter. Keyboard shortcuts have been added for several of the buttons. Randomization: Left-clicking the RAND button now randomizes all unlocked program parameters; right-click the button to open the Randomize Program Settings dialog. Buttons have been added for locking/unlocking program parameter sub-groups. Right-clicking a control in the Randomize Program Settings dialog now opens a sub-menu where you can place restrictions on which values can be generated when the parameter is randomized. In the main window, right-clicking a control now randomizes the parameter value. Randomization triggers have been added for each parameter. This enables the use of track envelopes for triggering parameter randomization at specific times during playback.
1.0.1 – Cosmetic revisions made to the Randomize Program Settings dialog and fixed some very minor display glitches in the export/import dialogs.
1.0.0 – First official Release!