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Regrader is a VST/AU plug-in which provides a delay effect in which the repeats degrade in various ways to provide a nice twist on the ears. The delays repeats can be synced to the host tempo and time signature and be fully automated.

If you require some inspiration, it is used pretty much all over the Imago album by Drosophelia. Alternatively, you can read what others say.

On compatibility

Build as VST 2.4

VST3 is great and all, but support across DAW's is poor (looking at a certain popular German product). You can however build as a VST2.4 plugin and enjoy it on a wider range of host platforms.

However: as of SDK 3.6.11, Steinberg no longer packages the required ./pluginterfaces/vst2.x-folder inside the VST3_SDK folder. If you wish to build a VST2 plugin, copying the folder from an older SDK version could work (verified 3.6.9. vst2.x folders to work with SDK 3.7.0), though be aware that you need a license to target VST2. You can view Steinbergs rationale on this decision here.

Once your SDK is "setup" for VST2, simply uncomment the following line in CMakeLists.txt:


And rename the generated plugin extension from .vst3 to .vst (or .dll on Windows).

Build instructions

The project uses CMake to generate the Makefiles and has been built and tested on macOS, Windows 10 and Linux (Ubuntu).

Environment setup

Apart from requiring CMake and a C(++) compiler such as Clang or MSVC, the only other dependency is the VST SDK from Steinberg (the projects latest update requires SDK version 3.7.0).

Be aware that prior to building the plugin, the Steinberg SDK needs to be built from source as well. Following Steinbergs guidelines, the build target should be a /build-subfolder of the /VST3_SDK-folder. To generate a release build of the library, execute the following commands from the root of the Steinberg SDK folder:

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
cmake --build .

The result being that {VST3_SDK_ROOT}/VST3_SDK/build/lib/Release/ will contain the Steinberg VST libraries required to build the plugin. NOTE: Windows users need to append --config Release to the last cmake (build) call as the build type must be defined during this step.

If you intend to build VST2 versions as well, run the following from the root of the Steinberg SDK folder (run the .bat version instead of the .sh version on Windows) prior to building the library:


And if you are running Linux, you can easily resolve all dependencies by first running the following from the root of the Steinberg SDK folder:


Building the plugin

Run CMake to generate the Makefile for your environment, after which you can compile the plugin using make. The build output will be stored in ./build/VST3/regrader.vst3 as well as symbolically linked to your systems VST-plugin folder (on Unix).

You must provide the path to the Steinberg SDK by providing VST3_SDK_ROOT to CMake like so:

cmake -DVST3_SDK_ROOT=/path/to/VST_SDK/VST3_SDK/ ..

Compiling on Unix systems:

mkdir build
cd build
cmake -DVST3_SDK_ROOT=/path/to/VST_SDK/VST3_SDK/ ..
make .

Compiling on Windows:

Assuming the Visual Studio Build Tools have been installed:

mkdir build
cd build
cmake.exe -G"Visual Studio 16 2019" -DVST3_SDK_ROOT=/path/to/VST_SDK/VST3_SDK/ ..
cmake.exe --build .

Running the plugin

You can copy the build output into your system VST(3) folder and run it directly in a VST host / DAW of your choice.

When debugging, you can also choose to run the plugin against Steinbergs validator and editor host utilities:

{VST3_SDK_ROOT}/build/bin/validator  build/VST3/regrader.vst3
{VST3_SDK_ROOT}/build/bin/editorhost build/VST3/regrader.vst3

Build as Audio Unit (macOS only)

Is aided by the excellent Jamba framework by Pongasoft, which provides a toolchain around Steinbergs SDK. Execute the following instructions to build Regrader as an Audio Unit:

  • Build the AUWrapper Project in the Steinberg SDK folder
  • Create a Release build of the Xcode project generated in step 1, this creates VST3_SDK/public.sdk/source/vst/auwrapper/build/lib/Release/libauwrapper.a
  • Run sh from the repository root, providing the path to VST3_SDK_ROOT as before:

The subsequent Audio Unit component will be located in ./build/VST3/regrader.component as well as linked in ~/Library/Audio/Plug-Ins/Components/

You can validate the Audio Unit using Apple's auval utility, by running auval -v aufx dely IGOR on the command line. Note that there is the curious behaviour that you might need to reboot before the plugin shows up, though you can force a flush of the Audio Unit cache at runtime by running killall -9 AudioComponentRegistrar.

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