CV Tools: Overview & Technical FAQ

What is CV?

CV is an abbreviation of "Control Voltage"; an analog method of controlling synthesizers, drum machines and other similar equipment.

What is CV Tools?

CV Tools is a free pack consisting of CV-enabled instruments, synchronization tools, and modulation utilities that enable users to seamlessly integrate Ableton Live with modular devices that utilize the Eurorack format.

Further reading:

Requirements for CV Tools 

  • Live 10 Suite (version 10.1 or later)
  • Live 10 Standard + Max for Live (version 10.1 or later)
  • A DC-coupled audio interface (for CV hardware integration)

Best Practices & Safety

  • Never send CV directly to your speakers.  (Direct voltage can cause damage to your speakers/hearing).
  • Modular systems can be especially sensitive to latency & timing issues.  To optimize your system for modular integration, please refer to the articles below:
  • Remember - Eurorack signals are up to 5x louder than line-level audio! Before connecting your modular system to a digital audio interface, be sure to reduce the signal down to line-level using a dedicated output module.

What is a "DC-coupled" audio interface? Why do I need one?

DC-coupling enables hardware devices to send (and, in rare cases, receive) a Direct Current.

However, since audio interfaces are optimized for audio-rate signals, most manufacturers opt for AC-coupled inputs/outputs. AC-coupling filters out ultra-low frequencies, including the types of sustained voltage inherent required for modular synthesis, making them an unreliable method of transmitting CV.  For a more comprehensive list of DC-coupled interfaces, please refer to this article from Sweetwater, or this article from Expert Sleepers.

Tested DC-coupled interfaces:

  • Expert Sleepers ES-3 & ES-8
  • Motu Ultralite (mk3 or mk4)
  • UAD Apollo Series (with some exceptions)
  • RME M-32 DA Pro (via optical & coaxial MADI connectors)
  • Komplete Audio 6 (2V output only)
  • Metric Halo ULN-8 / LIO-8

Note:  Although there are several interfaces on the market with DC-coupled outputs, the only known interface that also contains DC-coupled inputs are the ES Series interface modules made by Expert Sleepers.

I do not have a DC-coupled interface. Can I still use CV Tools?

Yes, even if you are not a modular user, there are interesting things to get out of CV Tools!

  • The Rotating Rhythm Generator outputs MIDI, and works great with Drum Racks in Live.
  • CV Clock / CV Clock Out / CV Triggers all work without DC-coupled interfaces, since binary events do not generally require exact voltage values.
  • The CV In device has a “Pitch” mode, which converts an oscillator’s pitch to CV in real-time (without the use of a DC-coupled input).
  • If you have a Eurorack MIDI interface, you can achieve similar results by using Live's External Instrument device.

Can I use CV Tools without any hardware at all?

Yes, CV Tools can be used in a number of creative ways that do not require any hardware.

  • Most devices in CV Tools have secondary mapping functions that can map to any parameter within Live.
  • With the help of ReWire or a virtual audio bus such as Soundflower (Mac) or VB-Cable (Windows), CV Tools can offer some flexible options for integration with "virtual modular" programs that utilize CV, internally (such as VCVRack/Max/Reaktor/et cetera).