A cross platform plugin (VST3, AU, Standalone) for the Elektron SidStation, the MOS6581 SID desktop synth.
Control the three Elektron SidStation voices individually from your DAW.
The documentation site is at benjamindehli.github.io/sidstation-asid, and builds for macOS, Windows and Linux are on the releases page. The plugin is also listed on KVR Audio.
SidStation ASID streams raw SID registers over the ASID protocol instead of sending MIDI CC, so every register is reachable and each voice gets its own pitch and gate. One instance drives one voice. Put an instance on each of three DAW tracks, pick a voice per track, and the three voices become three monosynths you can sequence apart. Getting that out of the SidStation on its own is awkward.
Put the unit in ASID mode from the front panel before playing.
Per voice:
- The four SID waveforms, combinable, with noise exclusive as on the real chip.
- ADSR envelope, pulse width, coarse and fine tuning, and pitch bend with an adjustable range.
- Hard sync, ring modulation, and the raw TEST bit.
- Portamento, with a legato or always trigger and a smooth or stepped glide.
- An eight step wavetable, each step with its own waveform, sync, ring, test, pulse width and arpeggio offset, plus a step length in frames or as a host tempo synced note division, a length and a loop point.
- Three LFOs (pitch, pulse width, cutoff) with several shapes, a free Hz or host tempo synced rate, depth, mod wheel scaling, and a fade in delay.
Shared across the three voices, since the chip has one of each:
- The filter: cutoff, resonance, per voice routing, external input, and combinable low, band and high pass modes.
- Master volume, and a switch to silence voice 3 so it can serve as a pure modulation source for ring and sync.
Around the sound:
- A Commodore 64 styled pixel interface, colour coded per voice.
- Voice presets saved to disk, so a sound outlives the DAW project it was made in. Init puts a voice back to its default sound.
- A tempo readout (the host tempo in a DAW, or set by hand in Standalone), and a Panic that releases every voice.
- A MIDI load meter, since the SidStation shares one slow MIDI port across all three voices.
The dark strip along the top is the same on every tab. It holds the MIDI output picker with a Scan button, the tempo and the clock rate, a MIDI load meter, the voice selector, and the preset bar (browse with the arrows or the menu, then Init, Save and Delete).
Everything that shapes a single voice. Oscillator has the four combinable waveforms with Sync, Ring, Test and Pulse Width. Tuning has coarse and fine pitch, the bend range, the glide time, and the glide trigger (Legato or Always) and type (Smooth or Step) switches. Amp Envelope is the ADSR.
An eight step table that drives the waveform and more, one step per tick. The top row sets whether it runs, plus speed, length and the loop point. Each step row carries its waveform (Tri, Saw, Pulse, Noise), Sync, Ring and Test, a pulse width fader, and an arpeggio offset. The loop point and the playing step are marked on the left.
Two LFOs for this voice, one on pitch and one on pulse width. Each has a shape, a rate that is free in Hz or locked to the host tempo as a note division, a depth, a Mod Wheel switch so the wheel scales the depth, and a fade in Delay. Set the shape to Off and the LFO stops.
The settings the SID shares across all three voices. Filter has per voice routing (V1, V2, V3), the external input, the combinable LP, BP and HP modes, and Cutoff and Resonance. Cutoff Modulation is a third LFO on the filter cutoff. Master has the Voice 3 Off switch, Volume, Latency and Panic.
- Overview: what the plugin does, the four tabs, install steps and screenshots.
- DAW setup: running it in Ableton Live, Logic Pro, Cubase, Reaper, Bitwig and FL Studio, what the three instances share, and getting the hardware's audio back into the mix. Pro Tools loads AAX only, so it cannot load this plugin at all.
- Sound design: the wavetable, the three LFOs, presets, and the SID rules that decide which waveform, ring and sync combinations do anything.
- Troubleshooting: no sound, only one voice, notes dropping on fast passages, uneven modulation, and trimming note timing against a DAW.
- ASID protocol: the frame format, the two address spaces, the dead Direct Program path on OS 1.11 R34, and what four real patch banks revealed.
- ASID timing: the write behaviour to design around when streaming ASID from a DAW.
- Usable for playing the three voices.
- Voice presets (save, browse, delete) are in. Factory presets are not yet.
- Developed and tested against OS 1.11 R34 hardware on macOS. Windows and Linux are untested.
| Directory | What it is |
|---|---|
core/ |
Framework agnostic C++17 library for the SidStation MIDI, SysEx and ASID protocols, with no dependencies and its own tests. |
asid/ |
The plugin itself, including its JUCE UI and MIDI device layer. |
probe/ |
Command line tool for checking the protocol against real hardware. |
Via CMake and JUCE:
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build buildJUCE is fetched automatically by the root CMakeLists. With copy after build on, the AU and VST3 land in your user plugin folders, and the Standalone app is the quickest way to test.
To run the core library tests without JUCE:
cd core && make testThree languages, three formatters, one command:
make formatclang-format handles the C++ in stock LLVM style, Prettier the docs site and Markdown and workflow YAML, and Ruff formats and lints the Python tools. The first run installs them into node_modules and .venv, pinned so a local run and a CI run agree. CI runs make format-check, which is the same thing without writing.
The full resolution PNGs live in assets/screenshots/. To rebuild the responsive set the site serves:
make imagesThat writes AVIF and WebP at 488, 976 and 1444 wide into docs/assets/screenshots/, which the <picture> elements in docs/index.html point at. The output is committed, because GitHub Pages serves docs/ as static files with no build step, so CI runs make images-check to catch a source updated without re-encoding. Replace a PNG in assets/screenshots/ and re-run to update a screenshot.
core/README.md records what came out of testing against a real unit, and the ASID protocol notes write the same ground up for reading. The finding that shaped the whole plugin: on OS 1.11 R34 firmware the SysEx Direct Program path is dead, so streaming raw SID registers over ASID is the only way in.