A free, open-source guitar effect by Music For Robots: an early-'80s thrash rhythm rig. It's a gate, a mid-hump overdrive pushing a cranked British master-volume head, a 4×12 and a plate reverb, for tight, scooped, palm-muted gallops.
- Gate, for clean stops between palm mutes.
- Overdrive: an op-amp mid-hump design that only adds gain and clips above about 720 Hz (about 12 dB more gain at 1.5 kHz than at 150 Hz). With drive low and level high, it tightens and pushes an already-distorted amp rather than adding fizz.
- Head: a cascaded-preamp master-volume design, with a bright first stage, a cold-biased second stage, and the classic passive treble/middle/bass tone stack. The tone stack is computed from the circuit (the Yeh & Smith analog model) in double precision. After it come an EL34-style power stage with Presence, and a 4×12 with an upper-mid bite.
- Plate: a small eight-line feedback-delay-network reverb, for that big early-'80s room.
The default EQ (Bass 9, Middle 1, Treble 3, Presence 7) was found by searching against the measured tonal balance of a reference recording's rhythm guitars. It lands within about 1.9 dB on average, from 125 Hz to 6.3 kHz. LightTest --fit reruns that search.
| Section | Controls |
|---|---|
| Gate | Threshold (all the way down = off), plus an open/closed light |
| Overdrive | ON, Drive, Tone, Level |
| Amp | Preamp, Master, AMP + CAB on/off |
| EQ | Bass, Middle, Treble, Presence (0–10) |
| Plate | Reverb amount |
| Out | Output, and INIT to reset everything |
Knobs: double-click or Alt-click resets a knob, Ctrl/Shift-drag gives fine control, and you can click a value to type one in.
Formats: VST3 and Standalone (Windows 64-bit). Stereo output (from the reverb), mono or stereo input.
Download the latest release from the Releases page. Use the installer, or copy MFR-Lightning.vst3 into C:\Program Files\Common Files\VST3\ yourself, then rescan plugins in your DAW.
Requirements: CMake 3.22+ and Visual Studio 2022 with the C++ desktop workload. JUCE 8 is included as a git submodule.
git clone --recursive https://github.com/music-for-robots/MFR-Lightning.git
cd MFR-Lightning
cmake -S . -B build -G "Visual Studio 17 2022" -A x64
cmake --build build --config Release
The built plugin ends up in build/Lightning_artefacts/Release/VST3/. There are two offline tools:
LightTestchecks the tone stack, the overdrive's mid hump, voicing against the reference curve, held-chord stability (8-second chords must decay smoothly), the gate and the output level. It fails on regressions.LightSnapshotrenders the UI to a PNG.
To package it locally, run scripts/package.ps1. It needs Inno Setup 6.
- Bump
VERSIONinproject(...)inCMakeLists.txt. - Add a section for the new version to
CHANGELOG.md. - Commit, then tag and push, e.g.
git tag v1.0.1 && git push origin v1.0.1.
GitHub Actions then builds the plugin, runs LightTest and pluginval (strictness 10), and publishes a release with the zip and the installer.
MFR-Lightning is licensed under the GNU AGPLv3 (or any later version). It is built with JUCE, which is used under the AGPLv3, and with the Steinberg VST3 SDK. VST is a trademark of Steinberg Media Technologies GmbH. MFR-Lightning is an independent project.