Stumbled upon this free and open source synth for linux, OSX and Windows. It looks lovely but more importantly; if you are just getting started with coding synths and want to have a look under the hood of completed project this is a nice source to look at.
- 32 voice polyphony.
- Interactive visual interface.
- Powerful modulation system with live visual feedback.
- Dual oscillators with cross modulation and up to 15 oscillators each.
- Unison and Harmony mode for oscillators.
- Oscillator feedback and saturation for waveshaping.
- 12 different waveforms.
- 7 filter types with keytracking.
- 2 monophonic and 1 polyphonic LFO.
- Step sequencer.
- Lots of modulation sources including polyphonic aftertouch.
- Simple arpeggiator.
- Effects: Formant filter, stutter, delay.
Helm is a free download for Windows, Mac, and Linux. A debian package download, and source code for mac/pc is also available from Github.
Download the compild version here; http://tytel.org/helm/