Reason CV to Moogerfoogers

Friday, June 5th, 2009 | 5:24 pm and filed in Reason, Gear, Tutorials.


The introduction of Volta from Mark of the Unicorn, is especially exciting news for those of us who have held on to our beloved analog gear. Volta is an application/plug-in that sends control voltage signals through MOTU hardware interfaces which can trigger and modulate analog hardware synthesizers and effects. The beauty of this system is that it is sample accurate and for old MOTU interface owners, adds new life to interfaces which might be considered obsolete.

I was pretty excited when I saw this since I have a MOTU 896HD (prior to volta I had seriously considered selling it). Then it dawned on me… in Reason 4.0, you can route control voltages to audio. Maybe i could create my own ‘ReVolta’? I’ve certainly used reason to trigger hardware envelope generators as gates, but the thought of sending DC signals from Reason had never crossed my mind before.

It was easy to test this out. I fashioned a couple of XLR to TRS cables, and connected them to a couple of audio outputs on my MOTU 896HD. In Reason’s audio preferences, I enabled the (normally dormant) motu outputs which would be used as control voltage sources. The plan was to route the connections to CV inputs on a Moog FreqBox and Moogerfooger Lowpass Filter.

Before making any connections, I read up on the MOTU specs and tested out the wiring with a voltmeter. Pin 2 is the positive connection and Pin 3 is the negative connection. The signal is DC coupled across the balanced outputs of the MOTU interface. To test the CV to DC relationship, an instance of Thor, with Rotary 1 routed to Audio Output 1, was connected directly into the Reason Hardware interface. Turning the rotary generated a steady DC voltage on the meter, which indicated that this was definitely going to work. One issue to take into consideration with this is that the moog devices have a low current +5dc on the ring, so the connections should be from the tip and the sleeve from pin2 and pin3 on the XLR. My cables also have pin 1 tied to the sleeve.


To convert Reason CVs to Audio signals, the CV source must be bridged through a Thor Polysonic Synthesizer. In the modulation matrix, set CV input 1 and CV input 2 as sources, Audio Output 3 and Audio Output 4 as destinations, and set the destination amounts to 100. For the Moogerfooger modulation setup, two Matrix Pattern Sequencers were created and the Curve CV outputs were patched into the Thor CV inputs. With this configuration, one Matrix Sequencer controlled the FreqBox’s pitch, and the other Matrix controlled the MF-101’s Cutoff setting. A Dr. REX provided a drum loop to process through the effect devices.

With the REX loop running through the effect boxes, I programming the Matrix Sequencers and listened as the two curve patterns modulated the Moog hardware. LFO Signals, Gate CV, Envelope Generators, Thor’s Sequencer all work great with this configuration. The one thing that I haven’t quite sorted out is accurate pitch control from the Matrix Note CV. A bit of CV math has to occur to make this work properly. When this is sorted, I’ll post some patches along with a few more details in setting this up with the Moog devices as well as other analog hardware.

Audio Demo of Moogerfooger Pitch and Filters modulated by Reason Matrix Pattern Sequencers:

CV to Moogerfoogers MP3 example

Audio Demo of Thor Step Sequencer (Note CV) controlling FreqBox pitch & Thor Envelope modulating Low Pass cutoff frequency. Live knob tweaking on top of repeating pattern sequence:

Thor to Moogerfoogers MP3 example

3 Responses to “Reason CV to Moogerfoogers”

  1. blacktiger Says:

    The filtered sounds are incredible! Any chance it could work with Digidesign hardware? :)

  2. Peff Says:

    man… i now have an RPG-8 sending CV/Gate to an analog synth. It’s pretty mindblowing. I’ll post some of this in a bit.

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