AMYplug

A free, open-source AU / VST3 instrument plugin that puts the AMY synthesizer inside your DAW — and can also drive a real AMYboard as hardware.

AMYplug loads AMY as a normal instrument: play it live, design and save patches, automate every knob, and have the whole sound recall perfectly with your project. It’s the first AMY plugin to exist.

Two plugins, one download: the AMYplug instrument, and AMYplugFX — AMY’s complete filter and effects bus (plus a bit crusher and a diode-clipper saturator) as a standalone insert effect for any track.

• macOS · Audio Unit + VST3 + Standalone · Apple Silicon & Intel · macOS 11+
• License: AGPL-3.0 (it links JUCE). AMY’s own C engine is MIT.

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⚠️ Read this first: one instance makes sound at a time

AMY is a single global engine — there is one of it per host process, not one per plugin instance. So only one AMYplug can be sounding at any moment, no matter how many you load. This is a property of AMY itself, not a bug or a licensing limit.

Load a second AMYplug and it deliberately stays silent rather than fighting over the engine (two renderers would corrupt each other’s voices and double-pull the sample clock). Its header shows:

○ SILENT · engine in use by another instance

…next to a USE ENGINE HERE button. Click it and the engine moves to that instance immediately — the other one falls silent. That’s the fast way to hop between AMYplugs while designing sounds; no rendering required.

Load as many instances as you like, in any order — they simply take turns. There’s no rule about removing one before adding another; only one is ever audible.

To have several AMY parts playing together in the final mix, print each finished part to audio (bounce/freeze that track). Only one instance can sound live, so a part that’s already audio doesn’t need the engine any more — hand it to the next instance with USE ENGINE HERE and carry on. You can leave the finished instance loaded and silent; it keeps its patch, so you can always reclaim the engine and revise it later.

Important: bypassing does not hand over the engine. A bypassed instance keeps holding it. The engine changes hands only when another instance takes it with USE ENGINE HERE, or when the current owner is removed or switched to Hardware mode (a silent instance then picks it up automatically).

Nothing is lost while an instance is silent. Every instance keeps its own complete state — patch, all parameters, engine choice — saved with your DAW project and restored on reload, whether or not it owned the engine. Your user patches are stored on disk (~/Library/Application Support/AMYplug/Patches/), so they’re shared by every instance and survive across projects. A silent instance is idle, not amnesiac.

The same rule applies to Hardware mode: there’s one physical AMYboard, so one instance owns it. The others show “board in use by another AMYplug instance” and stay idle until it’s freed.

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Two modes

Mode	What makes the sound	When to use it
Software (default)	AMY’s C engine compiled into the plugin, rendered right in your DAW	Everyday use. Full host automation, sample-accurate recall, and no hanging notes — the plugin owns every note on/off.
Hardware	A physical AMYboard over USB-MIDI; the plugin is the editor/librarian	Play and edit real AMYboard hardware from your DAW. The plugin sends silence; you record the board’s audio through your interface.

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Install — the easy way (no coding)

1. Download the latest AMYplug-macOS.zip from the Releases page.
2. Unzip it. You’ll get the AMYplug instrument (.component / .vst3), the AMYplugFX effect (.component / .vst3), an optional AMYplug.app (Standalone), and install.sh.
3. Run the installer. Open Terminal, type cd (with a trailing space), drag the unzipped folder onto the Terminal window, press Return, then run the script:

   cd /path/to/AMYplug-macOS
   ./install.sh

   It copies the AU + VST3 into your user plug-in folders and clears macOS’s Gatekeeper quarantine so your DAW will load them.
   • Want the standalone app too? ./install.sh --standalone
   • To remove everything later: ./install.sh --uninstall
4. Restart your DAW (or rescan plug-ins). AMYplug appears as an instrument by Mando369.

Why the installer, and why Gatekeeper? The plugins are ad-hoc signed, not notarized by Apple, so a downloaded copy is quarantined and macOS may say it “can’t be opened” or “is damaged.” That’s not a real problem — the installer runs xattr -dr com.apple.quarantine and re-signs locally, which is the standard fix. To do it by hand, see Troubleshooting.

Manual install (if you’d rather not use the script): copy AMYplug.component to ~/Library/Audio/Plug-Ins/Components/ and AMYplug.vst3 to ~/Library/Audio/Plug-Ins/VST3/, then run xattr -dr com.apple.quarantine on each.

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Install — build it yourself (developers)

Requires Xcode command-line tools, CMake ≥ 3.22, and git.

git clone https://github.com/Mando-369/AMYplug.git
cd AMYplug
./scripts/bootstrap.sh            # fetches the JUCE and AMY submodules
cmake --preset mac-release
cmake --build --preset mac-release
./scripts/install.sh              # installs what you just built

Run the tests / validation:

ctest --preset mac-release        # unit tests (Catch2)
auval -v aumu Amyp Mand           # AU validation

See CLAUDE.md for the architecture brief and docs/ for deeper notes.

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Quick start

1. Add AMYplug on an instrument track and play — it boots on a Juno-6 patch and makes sound immediately.
2. Open the editor. Use the patch browser at the top to pick any of AMY’s built-in sounds (Juno, DX7, piano, PCM…). They play straight away.
3. To change one, press “To Editor” first. Factory presets play as-is; To Editor decodes the selected preset into the editable engine and fills in every knob — a Juno preset lands on the Juno tab, a DX7 preset on the DX7 tabs, and the plugin switches you there. Until you press it, the tabs show the editor’s own settings, not the preset you’re hearing.
4. Now edit:
   • Juno — a full analog editor (OSC A–D, LFO, VCF + filter env, amp ADSR).
   • DX7 1–4 — a 6-operator FM editor; or import your own .syx cartridges.
5. Tweak, then Save… to store a named user patch. Everything you change is host-automatable and recalls with the project.

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Features

• All AMY engines reachable, with proper per-engine editors for Juno-style analog and DX7-style FM.

• Built-in patch browser with real names (Juno 0–127, DX7 128–255, piano, PCM presets).

• User patches — save/load your own; organized by cartridge on import.

• Import DX7 .syx cartridges (32-voice bulk dumps) straight into the browser — each import lands in its own named folder. Decades of DX7 patches are freely available; a good place to start is the huge Dexed Cart 1.0 collection compiled by Jacques Prestreau (BlackWinny).

• Voice modes: Poly / Mono / Legato (true pitch-only slur with glide/portamento), plus Unison with detune.

• Polyphony: 6 notes at once by default, for both the analog and FM engines (that’s the classic Juno-106 / DX7-era voice count). Turn it up to 16 with the Voices knob in the VOICE section — it’s host-automatable and saves with the patch like everything else. Unison (1–4) stacks extra detuned oscillator copies inside each voice, thickening notes without using up polyphony.

  The real limit is your CPU. AMY renders every voice in software, and each one costs: the analog engine builds 6 oscillators per voice (more with Unison), and each DX7 voice runs 6 FM operators. So 16 voices with Unison 4 is many times the load of the 6-voice default. If you hear crackles or your DAW reports overload, lower Voices (or Unison) first, or raise your audio buffer size.

• Juno LFO modes (Poly / Free / Key / Tempo-Sync).

• AMY’s full FX bus on the master — EQ, chorus, echo and reverb.

• Two extra output effects of our own, on top of AMY’s bus: a Bit Crusher (independent sample-rate + bit-depth reduction) and a Diode Clipper — a wave-digital-filter model of an antiparallel diode pair, for analog-style saturation rather than generic distortion. Both are Faust ports, and both are automatable like everything else.

• A second plugin included — AMYplugFX: the entire output section (filter + EQ + chorus + echo + reverb + bit crusher + diode clipper) as an AU/VST3 audio effect you can insert on any track. Unlike the instrument, you can run as many of these as you like.

• Full host automation of every sound parameter, with bit-faithful recall — the plugin keeps a canonical patch model that saves and restores with your DAW project.

• No hanging notes: deterministic note-off, transport-stop flush, and a Panic button.

• Hardware mode to drive a real AMYboard (see below).

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The interface, tab by tab

Everything above the tabs is always visible: the patch browser (factory presets + your own user patches, with Import DX7 and “To Editor”), the OUT GAIN master, an engine indicator showing whether you’re hearing Software or Hardware, the engine selector, and PANIC.

Playing a preset vs. editing it — the “To Editor” button

AMY’s built-in presets are stored as the engine’s own patch data, not as knob positions. Selecting one in the browser plays it immediately, but the Juno/DX7 tabs are a separate editable voice — so they keep showing whatever they hold, not the preset that’s sounding. The engine indicator tells you which you’re hearing: SOFTWARE · Factory means a browser preset, · Analog or · FM means the editable voice.

“To Editor” bridges the two. It decodes the selected factory preset into the editable engine, fills in every knob, and jumps you to the matching tab — Juno presets (0–127) to Juno, DX7 presets (128–255) to the DX7 tabs. From there it’s yours to change and Save… as a user patch. Your effects and output settings are kept; only the synth voice is replaced.

Piano and the AMYboard default (256–257) have no editable structure, so the button is greyed out for them — they play, but there’s nothing to decode.

This is also why a freshly-opened DX7 tab can look near-empty with five operators dimmed: that’s the editable voice at its DX7 INIT VOICE default (OP 1 only), not the preset you’re hearing. Press To Editor to pull the real patch in.

Juno — the analog engine

A full Juno-106-style voice. OSC A–D are the audio oscillators (wave, frequency, coarse/fine tuning, pulse width, level). VCF is the analog filter — cutoff, resonance, keyboard tracking, envelope amount and type — driven by its own VCF ENV, while AMP ENV shapes the level. LFO has selectable mode (Poly / Free / Key / Tempo-Sync), wave and rate, plus separate depths for pitch, PWM and filter. VOICE sets Poly / Mono / Legato, the Voices count (polyphony, 1–16), glide, and unison with detune.

Parameter-by-parameter mapping to the real Juno-106 (and what AMY does with each) is in docs/JUNO_PARAMETERS.md.

DX7 1 — algorithm & operator tuning

Pick one of the 32 FM algorithms and the diagram redraws to show which operators modulate which — modulators stacked above the carriers they feed, feedback marked. Feedback sets how hard the algorithm’s feedback operator drives itself. Below, each of the six operators gets its DX7-native tuning: Coarse, Fine, Detune, output Level, Vel (velocity sensitivity) and ratio/fixed Mode.

An operator sitting at Level 0 contributes nothing, so it’s faded — on its card, on its envelope row, and in the algorithm diagram. That’s why a fresh patch shows one bright operator: it’s the DX7’s own INIT VOICE (algorithm 1, OP 1 only), which is exactly why an un-edited DX7 sounds like a plain sine.

Want patches? Use Import DX7… to load any 32-voice .syx cartridge. The Dexed Cart 1.0 collection by Jacques Prestreau (BlackWinny) is an enormous, freely available starting point.

DX7 2 & 3 — operator envelopes

Each operator has the DX7's 4-stage rate/level envelope (R1–R4, L1–L4), drawn live as a curve so you can see the shape you're dialling in. Operators 1–3 live on DX7 2, operators 4–6 on DX7 3 — same layout on both.

DX7 4 — global pitch, LFO & routing

Transpose, the Pitch EG (its own 4-stage envelope applied to all operators), and the patch LFO — speed, wave, vibrato depth and sensitivity, tremolo — plus the per-operator switches for which operators the LFO's tremolo actually reaches.

FX-Master — the output section

Shared by both engines: EQ (low/mid/high), Chorus (level/rate/depth), Echo (level/time/feedback/tone) and Reverb (level/size/damping) — these are AMY’s own bus effects. Then the two host-side effects: Bit Crusher (sample rate + bit depth) and the Diode Clipper, a wave-digital-filter diode saturator whose Drive you push against Synth Vol, the level feeding it.

AMYboard — hardware control

Only needed if you own the hardware. Pick the board's MIDI port (notes) and Serial port (patch/parameter edits — Detect finds it), Connect to hand sound-making over to the board, Send Patch to Board to push the current patch, and Check for Firmware Update to compare the board's build against the latest release. The status line always states plainly what's making sound.

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Hardware mode (driving a real AMYboard)

Full guide: docs/HARDWARE_MODE.md.

Short version:

1. Connect the AMYboard by USB. In the plugin, switch to Hardware and pick the board’s MIDI port and Serial port (use Detect).
2. Notes are sent over USB-MIDI; patch/parameter edits go over the board’s serial REPL (the plugin handles both).
3. The plugin outputs silence in this mode — record the board’s audio through your interface.
4. Check for Firmware Update reads the board’s build over USB and compares it to the latest AMYboard release on GitHub. AMYboard firmware is a rolling release (no version number — a YYYYMMDD-<hash> build id), so it reports “up to date” or shows the newer build with a link to the WebSerial flasher. It never flashes for you. See docs/FIRMWARE_UPDATE_CHECK.md.

🌐 Heads-up: one optional internet request

Pressing Check for Firmware Update is the only time AMYplug talks to the internet — it makes a single HTTPS GET to the public GitHub Releases API (api.github.com/repos/shorepine/tulipcc) to read the latest firmware’s date + commit hash. No account, no token, and no data about you or your project is sent (just a User-Agent: AMYplug header). Nothing happens unless you click the button. Everything else in the plugin — audio, patches, editing, saving — is 100% offline.

⚠️ If hardware audio ever sounds glitchy, “bitcrushed,” or drifts in pitch/latency — CHECK YOUR AUDIO MASTER CLOCK FIRST.

A misconfigured macOS Aggregate Device (two interfaces with bad drift correction) causes exactly these symptoms, intermittently, and it will masquerade as a board or plugin bug. Use your interface directly on its own clock, or set a single clock master. This cost us a full debugging session — don’t repeat it. Details in docs/HARDWARE_LATENCY.md.

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AMYplugFX — the synth’s whole FX bus as an effect plugin

The download also includes AMYplugFX, an AU/VST3 audio effect that is AMYplug’s complete output section, usable as an insert on any track. Its DSP is extracted from AMY itself (engine-free, so any number of instances run independently), in the synth’s exact signal order:

Filter → EQ → Chorus → Echo → Reverb → Bitcrush → Diode Clipper → Output

• Filter — AMY’s analog VCF (LP 24/12, HP, BP) with cutoff/reso and an envelope follower so it opens with input level.
• EQ — 3-band (800 / 2500 / 7000 Hz), Chorus, Echo (time/feedback/tone), Reverb (size/damp) — the same AMY bus effects the instrument uses.
• Bitcrush + Diode Clipper — the Faust output-stage DSP (the diode is driven non-compensated here, so pushing Drive clips hotter/louder).
• Each effect has a bypass toggle in its title bar; every control is host-automatable.

It’s especially handy in Hardware mode: the instrument outputs silence, so insert AMYplugFX on the AMYboard’s audio-return track to process the board’s sound with the same effects.

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Troubleshooting

• “AMYplug can’t be opened” / “is damaged” → Gatekeeper quarantine. Run the installer, or by hand:

  xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/Components/AMYplug.component
  xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/VST3/AMYplug.vst3

• Plugin doesn’t show up → rescan plug-ins in your DAW. For AU, first-scan validation can take a moment; force it with auval -v aumu Amyp Mand. Logic caches AU results — quit and reopen if needed.
• No sound in Software mode → check the track isn’t muted and the plugin’s master volume is up; try loading a bright patch (e.g. a Juno lead) from the browser.
• Hardware mode is glitchy / laggy / pitch-drifting → see the master-clock warning above. Then confirm the board plays cleanly from amyboard.com/editor to isolate board vs. host.
• Wrong architecture → if the release build won’t load, build from source for your machine.

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Requirements

• macOS 11 (Big Sur) or newer, Apple Silicon or Intel.
• Any AU or VST3 host (Ableton Live, Logic, Reaper, Bitwig, Cubase, GarageBand, …), or run the Standalone app.
• Hardware mode additionally needs an AMYboard connected by USB.

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Support

AMYplug is free and open source, and it stays that way. If it’s useful to you and you’d like to say thanks:

☕ Buy me a coffee on Ko-fi

Entirely optional — bug reports and patches are just as welcome.

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License & credits

The plugin links JUCE 8 (free license: AGPLv3), so any distributed binary is AGPL-3.0 — see LICENSE. AMYplug’s own first-party sources are additionally offered under MIT where noted, but any binary that includes JUCE must comply with AGPL-3.0. Bundled AMY remains MIT and is kept as an unmodified submodule. Full third-party breakdown in NOTICES.md.

• AMY by DAn Ellis & Brian Whitman / Shore Pine Sound Systems (MIT).
• AMYboard hardware · shorepine/tulipcc.
• Built with JUCE (AGPLv3).
• DX7 patches — the Dexed Cart 1.0 cartridge collection compiled by Jacques Prestreau (BlackWinny). Not bundled with AMYplug and not affiliated with it — linked because it’s the most comprehensive freely-available source of .syx cartridges to import.
• AMYplugFX DSP — the filter, EQ, chorus, echo and reverb are extracted from AMY (MIT) into src/amyfx/; the bitcrusher and WDF diode clipper are ported from Faust under the STK-4.3 license (ba.bitcrusher by Julius O. Smith III, ba.downSample by Romain Michon, diode WDF model by Dirk Roosenburg, KalosSoftClipper.dsp by Thomas Mandolini). Full attribution in NOTICES.md; STK text in licenses/STK-4.3.txt.

How this was built

AMYplug is, so far, a hybrid human/AI project. It’s directed, specified and tested by a human — every sound-affecting change is verified by ear, and the hardware behaviour was confirmed against a real AMYboard — with the implementation written in collaboration with Claude (Anthropic), working from the brief in CLAUDE.md and the research notes in docs/.

Mentioning it because it’s honest and because it shapes the codebase: the docs are unusually thorough (they’re the shared context), and the design decisions and their reasoning are recorded rather than assumed. Bugs are still bugs — please report them.

This is an independent community project and is not affiliated with or endorsed by Shore Pine Sound Systems.

Repo: https://github.com/Mando-369/AMYplug — issues and PRs welcome.