Dexed is a free, open-source multi-platform FM synthesizer closely modeled on the Yamaha DX7. It exists so that the defining digital instrument of the 1980s — electric pianos, metallic basses, glassy bells, and brittle brass — is available to anyone without hunting vintage hardware or paying for a boutique recreation. Alongside the synth engine, Dexed doubles as a DX7 SysEx cartridge librarian, which is why collectors and patch archivists treat it as infrastructure as much as an instrument.
It excels at authentic FM timbres and patch interchange. Load a classic DX7 bank and you are hearing the language of 1980s pop, R&B, and soundtrack work: the EPs, the plucks, the mallet tones. Because it speaks SysEx, decades of community and commercial cartridges remain usable. Cross-platform builds (Windows, macOS, Linux) and VST/AU/LV2 support mean it fits nearly any serious setup, including free/open DAW stacks.
The trade-offs are the same ones the DX7 always had. Six-operator FM is powerful and unforgiving; parameter names like frequency ratio and envelope rates do not teach themselves. Dexed does not try to be a modern multi-engine synth — no wavetables, no sample layer, no giant effect rack. If you want guided FM with a visual matrix and factory polish, FM8 or a modern hybrid like Phase Plant / Surge XT may be faster for new sound design.
Against its alternatives, FM8 is the paid, friendlier FM workstation inside the NI ecosystem. Phase Plant and Surge XT are broader hybrid synths that include FM among many other engines. Reaktor is a modular playground, not a DX7 specialist. Choose Dexed when you specifically want free, accurate DX7-style FM and SysEx compatibility — it remains the standard open answer to that brief.