FM + AM synthesis, made visible

Bend a pitch fast enough and it becomes timbre.

FM/AM Sound Machine is a six operator synthesizer that turns the physics of synthesis into something you can see, and mind bending sounds into something you can play. In your browser, or as a Mac app.

6 operators · build any algorithm · 33 presets
a 303 sequencer · MIDI in · mic ring mod · no installs
What you are hearing
Carrier Sidebands Output
index 0.0 · sidebands appear at fc ± n·fm, at Bessel amplitudes. This is real FM, drawn live.
It shows its work

Most synths hide the synthesis. This one teaches it.

Every voice is colour coded down to the pixel, so you always know which line is doing what. A live spectrum draws the sidebands the math predicts, right where the new partials grow. The result is a synth that is genuinely fun to learn on, and deep enough to never leave.

Carrier

The tone you start from. Blue, everywhere, so you can follow it.

FM modulator

Wiggles the carrier pitch. Orange sidebands bloom in the spectrum.

AM modulator

Wiggles the volume. Violet, from soft tremolo to full ring mod.

Output

The sum of it all. Green, on the scope and in the wave you hear.

01 / THE ENGINE Six operators, build any algorithm

One deep engine, from a single sine to controlled chaos.

DX style phase modulation across six operators, with feedback you can wrap around a whole run of them, not just one. The AM stage rides on top, and one knob takes it from gentle tremolo all the way to ring modulation.

6 op phase modulation

Operators modulate operators. Sidebands grow their own sidebands, the way FM gets its bite.

Build your own

Start from the six classics or the 32 DX7 algorithms, then drag operators into your own routing and loop any run of them.

The AM continuum

Depth from 0 to 200 percent. Past full, the carrier cancels and only the sidebands survive: ring mod.

Per voice character

Filters with envelopes and key tracking, unison up to seven with stereo spread, a sub oscillator.

02 / SOUND DESIGN A warehouse in a web page

From a pure tone to a rave hoover in a few moves.

The tools you reach for when a patch needs to move: a real hoover kit, a 303 style step sequencer, an arpeggiator off a proper master clock, and a full effects rack.

The hoover kit

Unison swarm, a parallel octave layer, and the signature pitch swoop into every note.

16 step 303 sequencer

Slides that glide one voice, accents that bark the filter, ratchets that double a hit.

Character and space

Tube, fold and crush drive, chorus, tempo synced delay, and a doom reverb you can freeze forever.

Arp and pump

A hardware style arpeggiator and a sidechain pump, both locked to the same tap tempo clock.

03 / PERFORM Hands, keyboard, or voice

Play it however you want. Even with your own voice.

Plug in a controller, use the computer keys, or hold a chord and talk. The mic turns your keys into silent carriers, so the notes you play pitch your speech.

Real MIDI in

Velocity, pitch bend, mod wheel and sustain pedal, picked up the moment you connect a device.

Mic ring modulation

Your voice times the notes you hold. The classic robot vocoder trick, live.

XY pad and CC learn

Play two knobs at once, and map any hardware control to any parameter by wiggling it.

Record and bounce

Capture everything to a WAV, or bounce a tempo perfect, sample exact loop for your DAW.

04 / LEARN See the sidebands appear

The best way to understand FM is to watch it happen.

Five guided lessons walk you from a bare sine to a full hoover. A live spectrum predicts the sidebands with Bessel functions and draws them as ghost bars, right before they grow.

Five guided tours

What FM is, why bells ring wrong, AM to ring mod, filter and drive, and the anatomy of a hoover.

Predicted spectrum

Ghost bars mark where the partials will land, so the sound and the picture become the same fact.

Plain language read out

A caption that recomputes from your knobs and the last note, in words, not jargon.

33 patches, each explained

Every preset ships a short story on why it sounds the way it does. Learn by taking things apart.

The range

Thirty three ways in.

The factory bank spans the whole territory, from the first lesson in what a sideband is, all the way to a nine second doom drone you can freeze and walk away from.

Wherever you make sound

Runs in a tab. Or on your Mac.

The same synth and the same sound, whichever way you open it. Start in the browser in one click, or keep it in your dock for the moment inspiration hits.

In your browser

Open it and play

Nothing to install, and nothing to sign up for. It loads in a tab, and keeps working even when you go offline.

  • No sign up, no download, instant
  • Add it to your home screen if you like
  • Share any patch as a link
Open the machine →
On your Mac

A proper desktop app

The whole synth, in your dock and ready the moment you want a sound. Same feel, same interface, no browser in the way.

  • Opens with a double click
  • Plays your MIDI gear and your mic
  • All 33 presets, the lessons and the sequencer
Download for macOS ↓

Apple Silicon, macOS 11 or later. Unzip and drag it to your Applications folder.

Go make something strange

Open the machine.

Hold a chord, turn one knob, and watch the spectrum answer. That first moment is the whole pitch.