FM Synthesis: From the DX21 to the FM2 – A Journey Through Hardware Grit and Glory

My first real introduction to FM synthesis came through the Yamaha DX21 — a bottom-of-the-range keyboard that’s still a gem for anyone wanting to dip their toes into the FM world. You can pick one up for a pretty low price these days and despite its limitations, it offers a great crash course in the rawness and unpredictability of FM sound design.

The DX21 runs on a 4-operator FM engine, a stripped-back version of what you’d find in its more famous sibling, the DX7. While I did use it for certain sounds, I always had one eye on the DX7, knowing it could do more — and sound better.

But here’s the thing: the DX21 had charm. There’s a gritty, lo-fi quality to its sound that gives it a unique voice in the mix. It doesn’t try to sound smooth or polished — instead, it delivers abrasive textures, metallic edges, and harsh digital tones that somehow just work in the right context. For electronic music, especially when you’re looking for something with a bit more bite or character, that rawness becomes a strength.

It’s a synth that feels unrefined in the best possible way — a little wild, a little unpredictable, and very capable of surprising you. Whether you’re sculpting basslines, strange percussive hits, or alien pads, the DX21 can spit out weird and wonderful results that often feel more exciting because of their imperfections.

A few years later, I finally got hold of a DX7 II — the full stereo version, with deeper tone and, frankly, more balls. This synth is a beast. The bass tones in particular are where it shines — they cut through the mix with ease and always sit perfectly without much fuss. That’s the magic of a well-designed FM engine.

Owning both the DX21 and the DX7 II made the differences clear. The DX7 II had that polished edge, a clarity and depth the DX21 couldn’t match. But still — the DX21 had character. Its grit, its rough-around-the-edges textures — there was something charming about it. When I eventually sold it, I genuinely missed what it brought to the studio.

Fast-forward to today, and FM synthesis is still alive and kicking in hardware form. Korg’s Volca FM and especially the FM2 are carrying the torch in a big way. The FM2, in particular, puts me right back in that DX7 space. And considering you can load the original Yamaha DX7 library into it, there’s clearly some shared DNA in the architecture. It sounds solid — raw where it needs to be, but capable of pristine stereo tones too.

Plugin Versions

And if you’re more into working in-the-box, software has more than stepped up. Arturia’s DX7 V brings a beautifully enhanced take on the classic DX7, with extra features, effects, and a much more visual approach to editing. Then there’s Dexed, the open-source DX7 emulator that nails the architecture and lets you load original DX7 patches — totally free and surprisingly authentic.

These plugins have made FM synthesis more accessible and tweakable than ever, especially for those who might be intimidated by the often non-intuitive interface of the originals. Whether you’re hunting for that classic 80s bell tone, glassy pads, or biting basslines, there’s now a full spectrum of FM available — from battered vintage hardware with character to clean digital emulations.

So whether you’re picking up a cheap vintage unit, a classic synth icon, a modern reinterpretation, or diving into the plugin realm, hardware and software FM synthesis still offers something unique and inspiring. It’s not the easiest world to dive into — but if you’re feeling stuck or looking for new sonic directions, it’s absolutely worth your time.