Epsilon Audioby Epsilon Records

Free · Open source · MIT

Fourteen plugins
cut from one rock.

Synths, filters, a tape delay, a reverb, compressors, an EQ, a limiter, a gate, a de-esser and a multiband distortion from Epsilon Records. Every one is free, MIT-licensed and built for macOS, Windows and Linux.

Browse the plugins View on GitHub
14plugins, 2 instruments and 12 effects
482factory presets in total
VST3 · AUplus CLAP everywhere, VST2 on Windows and Linux
3platforms: macOS universal, Windows x64, Linux x64
Section A–A′ · release order, oldest at the baseBoundaries drawn as each plugin's signal

The catalogue

Pick a specimen

Numbered in release order. Each plugin lives in its own repository, with tests, presets and a Releases page holding builds for all three platforms.

How they fit together

Shared bedrock

Monolith's filter runs through most of the series. Later plugins borrow whole systems from earlier ones, so a sound you learn in one carries into the next.

Lineage: Monolith's filter feeds Caldera, Obsidian and Flint. Caldera's filters feed Strata and, simplified, Basalt. Obsidian's modulation feeds Strata. Gneiss, Mica, Granite, Slate, Magma, Talc, Schist and Geode stand on their own. filter filter filter simplified filters modulation MonolithSYNTH · 2002 SET CalderaDUAL FILTER ObsidianPOLYSYNTH FlintSATURATING FILTER BasaltLIVE DUAL FILTER StrataTAPE DELAY NEW GROUND GneissCOMPRESSOR MicaEQUALIZER GraniteLIMITER SlateGATE MagmaDISTORTION TalcDE-ESSER SchistMB COMPRESSOR GeodeREVERB
Monolith

Its 12 dB filter is a style in Caldera, Obsidian, Strata and Basalt (where it's called Fat). Flint is built on it.

Strata

Caldera's filters in the delay's feedback loop, driven by Obsidian's modulation system.

Basalt

Caldera with the modulation removed and the controls enlarged for live use.

Gneiss

The first dynamics plugin: a stereo compressor with sidechain.

Mica

The first mixing EQ.

Flint

A small, CPU-light filter with an envelope follower.

Granite

A look-ahead brickwall limiter with oversampling, dither and true-peak metering.

Slate

A gate and expander with five styles, sidechain filters and MIDI triggering.

Magma

Multiband distortion with 16 styles and a drag-and-drop modulation system.

Talc

A de-esser with single-vocal detection, linear-phase split-band processing and a sibilance display.

Schist

A multiband compressor and expander with freely placed bands and three phase modes.

Geode

An algorithmic reverb with a stepless space control, a decay rate EQ and a post EQ.

Download & install

Get them running

Every plugin's Releases page has one zip per platform. Pick yours.

    Latest releases

    Common to every plugin

    Same tools, same habits

    • Factory presetsBrowsable from each plugin's header.
    • MIDI Learn and user presetsSaved as small text files that load the same on every OS. Monolith leaves these to the DAW.
    • Published DSP techniquesPolyBLEP oscillators, Zavalishin topology-preserving state-variable filters, one-pole envelopes.
    • TestsIn each repository's tests/ folder.
    • MIDI on effectsCaldera, Strata, Magma and Slate take MIDI for key tracking, triggered envelopes, gate triggering and modulation. In Logic Pro, insert them as AU MIDI-controlled effects; elsewhere, route a MIDI track to the plugin.

    Build from source

    Compile with DPF

    All fourteen are built on DPF. Clone a plugin's repo, add DPF, then run make. On macOS this also builds the AU.

    git clone --recursive https://github.com/DISTRHO/DPF.git dpf
make -C plugins/<Name>

# Windows cross-build
make -C plugins/<Name> WINDOWS=true \
  CC=x86_64-w64-mingw32-gcc CXX=x86_64-w64-mingw32-g++

    Need the catalogue in a script? plugins.json lists every plugin with its repo, type, version, formats and CLAP ID.

    Lineage & clean-room note

    Where the feature sets come from

    The series works through FabFilter's catalogue in release order, recreating each product's feature set as a clean-room design. It now covers all fourteen products up to Pro-R.

    Epsilon pluginFeature set ofOriginal release

    Each plugin was written from scratch, working only from FabFilter's public press releases, product descriptions, manuals and contemporary reviews. No FabFilter code, binaries, presets, artwork or trademarks were used. FabFilter is a trademark of its owner; Epsilon Audio is not affiliated with or endorsed by FabFilter.