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.
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).
- The CV Instrument device is only capable of calibrating oscillators that use bipolar voltage (+/-5V) for 1v/oct. tuning. However, some digital oscillator modules exclusively use unipolar signals (+5V or above) for tuning. As a result, CV Tools will be incompatible with these modules. If you are unsure whether this applies to the modules in your system, please consult the user manual for the device.
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
- Antelope Audio Orion Studio Synergy Core
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 and the Orion Studio Synergy Core by Antelope Audio.
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).