AutoSimpler

An auto sampler VST3/AU plugin. AutoSimpler automatically samples any synthesizer or instrument and exports SFZ soundfonts with mapped WAV samples.

Insert AutoSimpler on a track, play a MIDI clip through your synth, and the auto sampler captures each note and exports a ready-to-use SFZ instrument with velocity layers, key splits, and trimmed samples.

Note: Only tested on macOS with Ableton Live. Other platforms and DAWs may work but are untested.

Features

• Auto-capture audio tagged by MIDI note number and velocity
• Velocity layers with automatic midpoint splitting
• Silence trimming with configurable threshold and zero-crossing detection
• Normalization scales all samples so the loudest hits 0dBFS while preserving relative dynamics
• Stereo/mono export toggle
• SFZ format compatible with sforzando, Sfizz, Decent Sampler, and any SFZ player
• 24-bit WAV samples at session sample rate
• 128-key piano roll with velocity axis visualization
• Suprematist UI inspired by Kazimir Malevich

DAW Setup

Ableton Live

AutoSimpler is an instrument plugin with a sidechain audio input.

1. Track 1 (MIDI): Load your synth, add MIDI clips with the notes you want to sample
2. Track 2 (MIDI): Load AutoSimpler as the instrument, duplicate the same MIDI clips
3. In AutoSimpler's device view, set the Sidechain input to Track 1
4. Set Track 2's monitor to In

AutoSimpler receives MIDI from its track's clips and audio from the synth via sidechain.

REAPER

Insert AutoSimpler after your synth in the same track's FX chain. MIDI flows through the entire FX chain automatically. No special routing needed.

Logic Pro

Use AutoSimpler as a MIDI-controlled effect on the synth track, or place it on a separate instrument track and configure audio sidechain routing from the synth track.

Usage

1. Click RECORD
2. Play your MIDI clip (one note at a time for cleanest results)
3. Click STOP
4. Click EXPORT SFZ..., enter a patch name, choose a folder
5. Load the exported .sfz file in your sampler of choice

Tips

• Leave gaps between MIDI notes to avoid audio bleed between samples
• Use the Release setting to capture the synth's natural decay after note-off
• The Threshold setting controls how aggressively silence is trimmed from sample heads and tails
• Playing the same note at the same velocity replaces the previous capture
• Playing the same note at different velocities creates velocity layers

Export Structure

For a patch named "Piano":

Piano/
  Piano.sfz
  Piano_samples/
    Piano_C4_vel64.wav
    Piano_C4_vel127.wav
    Piano_E4_vel64.wav
    Piano_E4_vel127.wav
    ...

The SFZ file automatically maps:

• Key splits at midpoints between adjacent sampled notes
• Velocity layers at midpoints between adjacent velocity values
• Single velocity captures span the full 1-127 range

Settings

Expand the settings panel with the triangle toggle at the bottom left.

Setting	Default	Description
Release	200 ms	How long to record after note-off
Threshold	-48 dB	Silence trim level for export
Normalize	On	Scale all samples relative to the loudest
Stereo	On	When off, mixes down to mono

Building from Source

Requirements: CMake 3.22+, Xcode (macOS), or a C++17 compiler.

JUCE 8.0.6 is fetched automatically via CMake FetchContent.

git clone https://github.com/wudpeker/autosimpler.git
cd autosimpler
cmake -B build -G "Unix Makefiles"
cmake --build build --config Release -j8

Plugins are automatically copied to:

• ~/Library/Audio/Plug-Ins/VST3/AutoSimpler.vst3
• ~/Library/Audio/Plug-Ins/Components/AutoSimpler.component

A standalone app is built at build/AutoSimpler_artefacts/Standalone/AutoSimpler.app.

License

All rights reserved.