Volt CB-1

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The Volt CB-1 is a control voltage combiner unit that lets you generate an output control voltage (CV) signal from two other input CV signals. Whereas the classic Reason CV Spider lets you merge multiple CV signals by adding them, the CB-1 adds a number of new operations.

  • Average : Average both input signals.
  • Minimum : Output the lowest of the two inputs.
  • Maximum : Output the highest of the two inputs.
  • Multiply : Multiply both input signals.
  • Subtract : The output is the difference between input A and input B.
  • Add : Classic addition of the two signals, same as the CV Spider.
  • Compare : Returns -1, 0 or +1 based on which of the two input signals is the greatest.

All these operations work on ALL types of CVs. Yes, you can multiply your gate and note CVs too! Cross device modulation has never been as powerful in Reason.



With the CB-1, both input signals can be multiplied before combination by a positive or negative factor, effectively enabling you to dynamically change the amplitude of your CVs as well as reversing them. This can be applied to the final combined signal as well.


For even more control, you can also adjust the balance between the input and combined signals in the output. With the simplest operation, average, this lets you cross-fade between two CVs.


With all these mixing and combination capabilities at hand, it is sometimes hard to visualize what modifications are applied to your signals. The CB-1 features three control voltage metering displays that lets you visualize your input and output CVs with all the operations applied to them.

The front panel with both input and output metering.


Input and output signals can be freely converted from / to unipolar or bipolar control voltages with convenient switches on the back panel.


Of course, all the front knobs and buttons can be fully automated inside your song tracks. On the back panel, the input / output multipliers and mix can also be controlled by CV signals coming from other devices. How more controllable can you get?

The back panel with all the available CV inputs and polarity switches.


“Molecule” by SH9, available at Polybonk.com.


The Volt CB-1 is available exclusively for Propellerhead Reason 6.5 and Reason Essential 1.5 on all supported hardware platforms. It can be purchased and downloaded through the Propellerhead Shop or through the links on the top right side of this page.