Full Bucket Matriq-Six: a free Oberheim Matrix 6R plugin prototype
Full Bucket Music releases Matriq-Six, a free Oberheim Matrix 6R emulation that runs the original OS on an emulated 6809 CPU. A prototype with candid limits.
German developer Bjørn Arlt (Full Bucket Music) has released Matriq-Six, a free emulation of the Oberheim Matrix 6R, the rack version of the 1985 Matrix-6 analog polysynth. Version 0.5.4, dated 23 October 2026 in the release notes, is billed as a prototype “for hardcore fans”.
It emulates the processor, not just the sound
Matriq-Six does more than mimic the Matrix 6R’s controls: it emulates the machine’s Motorola 6809 CPU and hardware, running an alternative ROM, version 2.15 by Bob Grieb (TaunTek). Interface behaviour, menus and patch handling are therefore those of the original.
The architecture follows the Matrix 6R:
- six voices, with two parts in keyboard split mode; the difference between voices and parts is explained in our voice count explainer;
- two digitally controlled oscillators (DCOs) per voice, more stable than VCOs;
- a resonant low-pass filter;
- three envelopes and two LFOs, routed through the modulation matrix that gave the range its name: each link pairs a source, a destination and an amount.
The prototype’s admitted limits
Full Bucket Music is unusually candid on its page:
- according to the author, the plugin does not sound like the hardware and its filters are weak;
- patches load only via SysEx over MIDI; tape import and export may not work;
- there is no manual: the author recommends getting the Matrix 6R owner’s manual, as the interface reproduces the original’s menu and keypad workflow;
- the page states that no AI tools were used in development; the code is native C++.
Who it is for, what it costs, what it competes with
Who it is for. Former Matrix-6 or Matrix 6R owners who want their workflow and SysEx banks back, and curious players ready to program a 1980s synth through its menus. Not for anyone after a ready-made Oberheim sound: the official page warns that it differs from the hardware.
What it costs. Free, downloadable directly from the official page with no sign-up. Formats: VST2, VST3, CLAP and AAX on Windows; VST2, VST3, CLAP, Audio Unit and AAX on macOS as a universal binary (Intel and Apple Silicon). The differences between these formats are covered in our plugin formats guide. The interface is resizable.
What it competes with. In software, the commercial reference is Arturia’s Matrix-12 V, sold for €149 on the publisher’s store: it emulates the twelve-voice big brother, with a modern interface and multimode filters, but does not run the original operating system. In hardware, the Matrix 6R is only found second-hand, and the Oberheim lineage lives on with the ACME XP60, a recreation of the Xpander, the eldest of the Matrix family. Matriq-Six stands out for its zero price and its faithfulness to how the machine works; it loses on sound, by its author’s own admission.
More free software in our Free and Open Source section, and more recreations in Vintage Emulations.
