cppsynth, short for C++ synthesizer, is a simple open source wavetable polyphonic synthesizer made in C++ with the JUCE framework. It can be compiled as a VST3 plugin, or as a standalone application.
A short demo of the plugin running inside Bitwig Studio can be found here : https://www.youtube.com/watch?v=t_3MBXmM0h8
- Dual wavetable oscillators, offering real time morphing between sine <-> triangle wave shapes, triangle <-> square wave shapes, and square <-> saw wave shapes
- Real time adjustment of OSC2's pitch by +/- 24 semitones and +/- 50 cents
- Polyphonic mode, with up to 10 voices simultaneously, and monophonic mode with last note priority
- White/Pink noise generator
- Sine wave low frequency oscillator (LFO) (~0-20Hz), with adjustable depth for pitch, low pass filter cutoff frequency, and high pass filter cutoff frequency
- ADSR amplitude envelope with attack/decay/release adjustable between 0-10 seconds
- State variable low pass and high pass filters, with adjustable cutoff frequency (0-20000Hz) and resonance, each with their own reversable ADSR envelope
- Overall output level adjustment from -24dB to +6dB, and overall pitch adjustment by +/- 100 cents
- MIDI keyboard input, with support of sustain, mod wheel and pitch wheel functionalities
- Additional features : Ring mod, phase randomizer on new note, and velocity sensitivity toggle
You will need the latest version of JUCE 7. To remove the JUCE splash screen, make sure to enable GPL Mode by clicking on the "Sign in..." button at the top right of the Projucer window, and selecting "Enable GPL Mode".
You will need Xcode and the Command Line Tools for Xcode in order to build the project.
- Open the
cppsynth.jucerproject in JUCE's Projucer - Make sure the selected exporter is set to Xcode (MacOS), and click on the "Save and export to IDE" button
- In the scheme selection dropdown at the top of the IDE, select either "cppsynth - VST3" or "cppsynth - Standalone Plugin"
- Build the project using the Start button, or by pressing
cmd+B - The exported build will be in the
cppsynth/Builds/MacOSX/build/Releasefolder - If you compiled the project as a VST3 plugin, make sure to move the VST3 file to a folder that your DAW will recognize!
You will need Visual Studio 2022 with C++ in order to build the project.
- Open the
cppsynth.jucerproject in JUCE's Projucer - Make sure the selected exporter is set to Visual Studio 2022, and click on the "Save and export to IDE" button
- In the Solution Configurations dropdown menu at the top of the IDE, select "Release"
- In the Solution Explorer, select either "cppsynth_StandalonePlugin" or "cppsynth_VST3"
- Build the project by right clicking on the selected solution and selecting "Build", or by pressing
ctrl+shift+B - The exported build will be in the
cppsynth\Builds\VisualStudio2022\x64\Releasefolder - If you compiled the project as a VST3 plugin, make sure to move the VST3 file to a folder that your DAW will recognize!
The goal of this project was for me to learn about audio synthesis and digital signal processing, and to discover C++ and the JUCE framework. Making this project was mostly possible thanks to the excellent Creating Synthesizer Plug-Ins with C++ and JUCE book by Matthijs Hollemans (@hollance, The Audio Programmer), as well as various tutorials on sound synthesis by Jan Wilczek (@JanWilczek, WolfSound). Big thanks! Other references are directly in the code as comments.
The font used for the user interface is the JetBrains Mono font.
Since this project was done mostly as a learning exercice, this plugin is far from perfect, and there will be a lot of (maybe obvious and unnecessary) comments. Comments preceded by "LRN" are notes about C++/JUCE/audio programming concepts I learned while making this project. Feel free to clone or fork it, and make it better!