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Reason CV tutorial

My first project, written in July 2012, was a tutorial series about using (virtual) control voltages (CV) in Propellerhead's Reason software. CV can be kind of mysterious. Different devices seem to vary in how they calibrate or interpret CV signals. For example, the pitch-tracker Neptune puts out a Pitch CV signal that is calibrated to drive Thor's oscillators, but not to match the Sequencer Control note/pitch CV inputs used by other synths. In order to understand and manage these kinds of issues, I developed some analytical tools for looking at CV signals.

This series was written when Reason 6 was current. Reason 6.5 came out just a few months later, with support for Rack Extensions (REs), Propellerhead's proprietary plug-in format. In the following months and years, third-party developers released a number of REs to do all kinds of signal processing on CV signals. These tools make it very easy to do the kinds of manipulations described in this series. Still, you may find these tutorials useful for understanding basic CV signal processing in Reason. And you can still use these techniques even in the most recent versions of Reason.

Some clarifications

2019-10-31

The UIs of Reason devices and REs have various controls that represent CV sources and targets — knobs, sliders, modulation matrixes, etc. These may be calibrated as integer values 0-100, 0-127, -64 to +63, etc. Or they may be shown as floating-point values 0.0 to 1.0, -1.0 to +1.0, etc. It is important to keep the following points in mind:

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