VCV Rack is a virtual modular synthesizer that is free and open source. It can be used to patch together modules for sound design and music creation all by itself, and it can also be used with MIDI controllers.

You'll use it with the excellent Stoermelder MIDI-CAT and Trowasoft trigSeq modules so that the NeoTrellis 8x8 can both send and receive MIDI messages. This is a simplified version of the excellent system created by PatchworkBoy here.

MIDI messages sent from the NeoTrellis to Rack will be used to change the sequencer trigger patterns of three drums and a bass synth.

In the other direction, MIDI messages from Rack to the NeoTrellis will be used to keep the NeoPixel lighting in sync with the on-screen GUI.

VCV Rack and Plugins Required

• VCVRack2 + Fundamentals
• Audible Instruments (Mutable Instruments) Plaits
• Stoermelder PACK-ONE Dev Builds
• Trowasoft-VCV

Download and install VCV Rack 2 for your operating system. This will include the Fundamental modules as well.

Then, from the Rack Library, install Audible Instruments Macro Oscillator 2 (software version of the esteemed Mutable Instruments Plaits module).

Download Stoermelder PACK-ONE. Then, put the .vcvplugin file in the /Documents/Rack/plugins directory.

Finally, download the Trowasoft-VCV dev build. Extract the zip, then place the folder in the /Documents/Rack/plugins directory.

Use the Controller with Rack

Once the controller is selected in the MIDI-CAT module, hit Reset and then Play in the Pulses module to start the trigger sequencers.

Now, you can add triggers to any of the four drum sequencers with the NeoTrellis and the VCV Rack GUI will match. Same goes for the other direction! Click any triggers in the Trowasoft trigSeq modules and the NeoTrellis will adjust the NeoPixels to match.

Acknowledgements

This project would not have been possible without the excellent work done by PatchworkBoy in creating the TrowasoftControl code, workflow, and example patch seen here.