SM-26

A self-contained subtractive synthesizer written in modern C++ on top of JUCE. It ships as a VST3 on macOS and Linux plus a macOS Audio Unit, with a hand-rolled DSP core, 320 factory presets and an embedded 4x80 HD44780-style LCD driven by a cascaded on-screen menu.

Why this is (still) pretty good

One real dependency, always fetchable. JUCE is the only external thing this project needs, and the build fetches it automatically into ./build/ on the first make. Your source tree stays clean: no vendored JUCE, no submodules to go stale, no manual setup.
A tiny, readable DSP core with real character. Twelve voices, two oscillators with gliding, a self-oscillating state-variable filter with drive, an ADSR, and a tempo-synced delay — all in one focused SynthEngine with no external DSP libraries. Easy to read, easy to hack.
A UI people actually look at. A 4x80 pixel LCD renderer with a real menu (PRESETS / OSCILLATORS / FILTER / ENVELOPE / DELAY / SYSTEM) navigated with a diamond of arrow keys plus ENTER/ESC. A DAW-native plugin that wears its own little OS.
Knobs that mean something. Four front-panel knobs that change meaning per preset (KnobView) — every preset ships with a curated mapping and a sensible value range, not just raw MIDI CCs.
Reproducible from a single command. make = fetch JUCE → configure → build → you're done. make install even ad-hoc-signs and un-quarantines the macOS bundles so your DAW and auval accept them immediately.

Features

12-voice polyphonic engine with voice stealing and glide
320 factory presets across Bass / Lead / Pad / Keys / Pluck / String / Organ / Bell / Stab / Arp / FX / Wind / Brass / Voice / Perc / SFX / Grit / Retro / Ambient
Click the patch line on the LCD to open a categorized preset browser
Dual-waveform oscillator section (sine / tri / saw / square / noise …)
SVF low-pass filter with resonance and drive
ADSR with a per-voice envelope and cutoff modulation
Tempo-synced delay with rhythmic subdivision, locked to host BPM
4x80 LCD with live knob values, active preset, voice count and transport
Footer that shows the exact git revision and build time

Requirements

C++17 compiler (Apple Clang or GCC)
CMake >= 3.22
Git (to fetch JUCE on the first build)
Linux: X11/ALSA development headers

Build

make            # fetches JUCE into build/ (once), configures and builds
make install    # installs + ad-hoc signs + un-quarantines the plugin bundles
make uninstall  # removes the installed plugins
make clean      # removes compiled artefacts only
make distclean  # wipes build/ entirely (including the fetched JUCE)

macOS installs to ~/Library/Audio/Plug-Ins/ (AU + VST3).
Linux installs to ~/.vst3/.

Jumping straight into CMake also works: cmake -S . -B build builds a Release plugin and grabs JUCE from the same build/juce location.

If a freshly installed AU is not visible to auval / your DAW:

sudo killall -HUP coreaudiod

(or just restart the host).

Usage

Feed the plugin MIDI; the four front-panel knobs drive whichever parameters the current preset maps them to (cutoff, resonance, envelope, delay — and a wide range of other routings).
Navigate with the arrow diamond + ENTER/ESC:
- root → PRESETS / OSCILLATORS / FILTER / ENVELOPE / DELAY / SYSTEM
- up/down move, left/right adjust, ENTER opens/confirms, ESC goes back
The LCD shows the active preset, knob mappings with live values, host BPM and voice count. The delay's SYNC mode locks to the host tempo and lets you pick rhythmic subdivisions.
Click the patch line on the LCD to browse presets by category: a "SELECT PATCH CATEGORY" menu opens, ENTER drills into a category, and confirming a patch loads it and returns you home.

Layout

Build: Makefile -> CMake -> JUCE (fetched into build/juce, never committed)
Source/
  PluginProcessor.*  audio processor + DSP shell
  SynthEngine.*      osc/filter/ADSR/delay voice engine (12 voices)
  Presets.*          320 preset definitions + per-preset knob routings
  SynthParams.*      parameter model + formatting
  PluginEditor.*     panel, knobs, nav diamond, status footer
  LcdDisplay.*       4x80 HD44780-style display renderer
  MenuSystem.*       cascaded menu state machine
tools/gen_buildinfo.sh  generates git-revision + build-time header

Everything the project needs at build time lives under ./build/, which is git-ignored — the only things committed are your sources, this README and the build glue.

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