StutterCappy

StutterCappy is a tempo-synced stutter Audio Unit for Logic Pro. It captures the audio immediately before the effect is triggered, loops it rhythmically, and can accelerate from one note division to another for ratchet-style builds.

Features

• Tempo-synced rates from 1/4 to 1/64, including triplets
• Automatable Stutter trigger for placing the effect over individual regions
• Accelerating repeats with start rate, end rate, duration, and curve controls
• Reverse playback, stereo spread, gate, decay, dry/wet mix, and automatic recapture
• Mono and stereo processing
• Native Audio Unit v2 support for Logic Pro
• Standalone application for testing outside Logic

Download and install

The easiest installation is the prebuilt universal macOS release:

1. Open the latest release.

2. Download StutterCappy-AU-macOS-universal.zip.

3. Unzip it to reveal StutterCappy.component.

4. Quit Logic Pro.

5. In Finder, choose Go → Go to Folder… and enter:

   ~/Library/Audio/Plug-Ins/Components
   

6. Copy StutterCappy.component into that folder.

7. Reopen Logic Pro and insert Audio FX → Audio Units → StutterCappy Audio → StutterCappy.

The release contains both Apple Silicon and Intel code and targets macOS 12 or later. It is ad-hoc signed but not Apple-notarized. If macOS quarantines the download, verify that it came from this repository's release page and remove quarantine only from this plug-in:

xattr -dr com.apple.quarantine "$HOME/Library/Audio/Plug-Ins/Components/StutterCappy.component"
killall -9 AudioComponentRegistrar 2>/dev/null || true

You can also download StutterCappy-Standalone-macOS-universal.zip to test StutterCappy without opening Logic.

Using StutterCappy in Logic Pro

1. Put StutterCappy on the audio track containing the region you want to affect.
2. Play the project so the plug-in's history buffer receives audio.
3. Choose a Slice Rate, then adjust Gate, Decay, and Mix.
4. Press A in Logic to show automation.
5. Select StutterCappy → Stutter as the automation parameter.
6. Draw Stutter on over the portion of the region that should repeat, then turn it off at the end.

Audio Units cannot directly inspect or rewrite Logic's currently selected region. StutterCappy instead processes its track and exposes every creative setting to Logic automation, which lets the automation follow the exact region boundaries.

Creating an accelerating stutter

For a classic ratchet build:

1. Set Slice Rate to the starting speed, such as 1/16.
2. Enable Accelerate.
3. Set End Rate to the fastest division, such as 1/64.
4. Set Ramp Length to the intended effect length in beats.
5. Use Ramp Curve to choose whether the speed-up happens early, linearly, or near the end.
6. Automate Stutter on at the beginning of the region and off at its end. The ramp restarts each time Stutter turns on.

Controls

Control	Purpose
Stutter	Captures the preceding slice and starts or stops repetition.
Slice Rate	Selects the starting tempo division.
Accelerate	Enables the tempo-synced frequency ramp.
End Rate	Selects the target division for the ramp.
Ramp Length	Sets the ramp duration from 1 to 32 beats.
Ramp Curve	Moves the acceleration earlier or later in the ramp.
Auto Capture	Refreshes the frozen audio every eight repeats.
Reverse	Plays each captured repeat backward.
Gate	Shortens each repeat to create rhythmic space.
Decay	Progressively reduces repeat level.
Spread	Offsets the right-channel loop for stereo motion.
Mix	Blends dry and processed audio.

Build from source

Requirements:

• macOS 12 or later
• Xcode
• CMake 3.22 or later
• Git and an internet connection for the initial JUCE download

git clone https://github.com/zach1020/StutterCappy.git
cd StutterCappy
./install.sh

The script builds in a temporary directory, installs the Audio Unit in ~/Library/Audio/Plug-Ins/Components/, and creates a standalone ZIP in the repository folder.

To build manually:

cmake -S . -B build -G Xcode -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64"
cmake --build build --config Release --target StutterCappy_AU StutterCappy_Standalone

Validation

Version 1.0.0 passes Apple's auval validation, including custom UI loading, parameter publication and restoration, mono/stereo channel handling, host callbacks, scheduled automation, and rendering from 11.025 kHz through 192 kHz.

License

StutterCappy is released under the GNU General Public License v3.0. It uses JUCE; review JUCE licensing before distributing a modified closed-source build.