Helm - a free polyphonic synth with lots of modulation
Clone or download



Helm is a free, cross-platform, polyphonic synthesizer that runs on GNU/Linux, Mac, and Windows as a standalone program and as a LV2/VST/AU/AAX plugin. Release is in beta so there are outstanding bugs. Please send any bugs found to matthewtytel@gmail.com


Go to tytel.org/helm for builds.


If you want to build AAX plugins You'll need its SDK located in ~/srcs
For AU on the Mac you'll want to put the CoreAudio SDK in /Applications/Xcode.app/Contents/Developer/Extras/CoreAudio
Nothing extra is needed for building VST/LV2 plugins


To build and install the standalone, lv2 and vst plugin:

sudo make install

Other make commands:

# Build just the Linux standalone executable:
make standalone

# Build just the Linux LV2 plugin:
make lv2

# Build just the Linux VST plugin
make vst

# Install just the Linux standalone executable:
sudo make install_standalone

# Install just the Linux LV2 plugin:
sudo make install_lv2

# Install just the Linux VST plugin
sudo make install_vst

The standalone executable is built to standalone/builds/linux/build and installed to /usr/bin The LV2 plugin is built to builds/linux/LV2 and installed to /usr/lib/lv2 The VST plugin is built to builds/linux/VST and installed to /usr/lib/lxvst


Open /standalone/builds/osx/Helm.xcodeproj for standalone version
Open /builds/osx/Helm.xcodeproj for plugin versions


Open /standalone/builds/vs15/Helm.sln for standalone version
Open /builds/vs15/Helm.sln for plugin versions


  • 32 voice polyphony
  • Interactive visual interface
  • Powerful modulation system with live visual feedback
  • Dual oscillators with cross modulation and up to 15 unison oscillators each
  • Sub oscillator with shuffle waveshaping
  • Oscillator feedback and saturation for waveshaping
  • 12 different waveforms
  • Blending between 12 or 24dB low/band/high pass filter
  • Low/Band/High Shelf filters
  • 2 monophonic and 1 polyphonic LFO
  • Step sequencer
  • Lots of modulation sources including polyphonic aftertouch
  • Simple arpeggiator
  • Effects: Formant filter, stutter, delay, distortion, reverb

alt tag