In a few short weeks since it was released, VCV Rack has transformed how you might start with modular – by making it run in software, for free or cheap.

VCV Rack now lets you run an entire simulated Eurorack on your computer – or interface with hardware modular. And you can get started without spending a cent, with add-on modules available by the day for free or inexpensively. Ted Pallas has been working with VCV since the beginning, and gives us a complete hands-on guide.

There’s always a reason people fall in love with modular music set-ups. For some, it’s having a consistent, tactile interface. For others, it’s about the way open-ended architectures let the user, rather than a manufacturer, determine the system’s limits. For me, the main attraction to modulars is access to tools that can run free from a rigid musical timeline, but still play a sequence. It means they let me dial in interesting poly-rhythmic parts without stress.

An example: I hooked a Mutable Instruments Braids up to a Veils modular, triggered their VCA with an LFO, and ran the resulting pulse through a Befaco Spring Reverb. I used this patch to thicken the stew on a very minimal DJ mix. I also had a simple LFO pointed at a solenoid attached to a small spring reverb tank boinging away in a channel on the master mixer.

This is all pretty standard Eurorack deployment, except for one tiny detail – all of the modules exist in software, contained inside a cross-platform app called VCV Rack.

VCV Rack is an open-source Eurorack emulation environment. Developer Andrew Belt has built a system to simulate interactions between 0-5 volt signals and various circuits. He’s paired this system with a UI that mimics conventions of Eurorack use. Third-party developers are armed with an API and a strong community.

VCV Rack is open-source, and the core software is free to download and use. The VCV Rack website also features several sets of modules as expansions, many of which are free. The most notable cost-free VCV offering is a near complete set of Mutable Instruments modules, under the name Audible. Beyond the modules distributed by developer Andrew Belt, there’s an ecosystem of several dozen developers, all working on building and supporting their own sets of tools – the vast majority of these are free as well, as of the time of this writing.

The result is a wide array of tools, covering both real-world modules (including the notable recent addition of the Turing Machine and a full collection of Audible Instruments emulations) and original circuits made just for Rack. The software runs in Windows, Mac OS and Linux, though the system doesn’t force third-party developers to support all three platforms.

VCV Rack is a young project, with its first public build only having become available September 10th. I became a user the same day, and have been using it several times a week for several months. I don’t usually take to new software so quickly, but in Rack’s case I found myself opening the app first and only moving on to a DAW after I had a good thing going. What continues to keep me engaged is the software’s usability – drop modules into a Rack, connect them with cables, and the patch does what it’s patched to do. Integration with a larger system is simple – I use a MOTU 828 mk2 to send and receive audio and CV through and audio interface module, and MIDI interfacing is handled in a similar fashion through a MIDI module. I can choose to clock the system to my midiclock+, or I can let it run free.

VCV Rack runs great on my late 2014 MacBook Pro – I’ve heard crackling audio just a handful of times, and in those cases only because I was doing dumb things with shared sound cards. To a lesser degree, VCV Rack also runs well on a Microsoft Surface Pro 3, though using the interface via touch input on the Surface is fiddly at best. Knobs tend to run all the way up or all the way down at the slightest nudge, and the hitbox for patch cable insert points is a bit small for your fingers on any touch screens smaller than 15”. Using a stylus is more comfortable.

Stability is impressive overall, even at this early pre-1.0 development stage. Crashes are exceptionally rare, at least on my systems – I can’t specifically remember the last one, though there’s been a few times the aforementioned crackles forced me to restart Rack. Restarting Rack is no big deal, though – on relaunch, it restores the last state of your patch with audio running, and more than likely everything is ok. Rack will mute lines causing feedback loops, a restriction which ultimately serves to keep your ears and your gear safe.

As part of my field work for this write-up, I decided to run a survey. The VCV Rack community is more approachable, open, and down to get dirty with problem-solving than any other software community I’ve participated in directly. I figured I’d get a handful of responses, with variations of “it’s Eurorack but on my computer and for free” as the most common response.

Instead, I got a peek inside a community excited about the product bringing them all together. Over a third of the respondents have been using VCV since early September, and a quarter of the respondents have only been using the tool for a few weeks. Across the board, though, there’s a few key points I think deserve a highlight.

“Modular is for everybody”, and VCV Rack is modular for everybody.

Almost every single one of our 62 respondents in some way indicated that they love hardware modular for its creative possibilities, but also see cost as a barrier. VCV Rack gets right around the cost issue by being free upfront, with some more exotic modules costing money to access. There’s also a solid chunk of users coming from a university experience with large modular systems, such as Montreal’s SYSTMS, who say what initially appealed to them was “getting to explore modular, whereas before that was just not available to a low income musician. I had been introduced to Doepfer systems in university, and since then I have of course not had access to any very expensive physical Eurorack set ups. Also the idea of introducing and teaching my friends, who I knew would be into this!”

(While Rack is especially hardware-like, I do want to shout out fellow open-source modular solution Automatonism – you won’t find anything like a complete set of Mutable modules, but you will find a healthy Pd-driven open source modular synth with the ability to easily execute away from a computer via the Critter and Guitari Organelle.)

VCV Rack can be used in as many ways as a real Eurorack system.

The Rack Github describes Rack as an “Open-source virtual Eurorack DAW,” and while I wouldn’t use it to edit audio, Rack can handle a wide enough set of roles in a larger system to fairly call the software a workstation. There are several options for recording audio provided by the community, with an equal number of ways to mix and otherwise manipulate sets of signals. It’s possible to create stems of audio data and control data. It’s possible to get multiple channels of audio into another piece of software for further editing, directly via virtual soundcards.

VCV Rack also has a home within hardware modular systems, with users engineering soundcard-driven solutions for getting CV and audio in and out of a modular rack running alongside VCV. User Chris Beckstrom describes a typical broad array of uses: “standalone to make cool sounds (sampling for later), using Tidal Cycles (algorithmic sequencer) to trigger midi, using other midi sources like Bitwig to trigger Rack, and also sending and receiving audio to and from my diy modular.”

8th graders can make M-nus-grade techno with it.

I mean, check it out.

If you build it, they will come.

For having been around only since early September VCV Rack already has a very healthy ecosystem of third-party modules. Devs universally describe Rack’s source as especially easy to work with – Jeremy Wentworth, maker of the JW-modules series, says “[Andrew Belt’s] code for rack is so easy to follow. There is even a tutorial module. I looked at that and said, hey, maybe I can actually build a module, and then I did.” Jeremy is joined by over 40 other plug-in developers, most of whom are managing to find their own Eurorack recipe. VCV Rack also has a very active Facebook community, with over 100 posts appearing over the three days this article was written in. I’ve been on the Internet for a long time – it’s unusual to find something this cohesive, cool-headed and capable outside of a forum.

The community aren’t just freeloaders.

Almost two thirds of our respondents have already purchased some Rack modules, or are going to be purchasing some soon. Only a handful plan not to purchase any modules. There’s a market here, a path to the market via VCV Rack, and a group of developers already working to keep people interested and engaged with both new modules and recreations of real-world Eurorack hardware. Two thirds of respondents is a big number – if you’re a DSP-savvy developer it’s worth investigating VCV Rack.

DSP is portable.

The portability of signal processing algorithms isn’t a phenomenon unique to VCV Rack, but it is my opinion, VCV Rack will be uniquely well-served by the ability to easily port DSP code and concepts from other plaforms. Michael Hetrick’s beloved Euro Reakt Blocks are being partially ported from Reaktor Core patches into VCV Rack, for example, and Martin Lueder has ported over Stanford’s FreeVerb as part of his plugin pack. As the community cements itself, we’ll likely only see more and more beloved bits of code find their way into VCV Rack.

A handful of cool, recent VCV developments

VCV Rack are selling commercial modules. Pulse 8 and Pulse 16 are drum-style Sequencers, and there’s also an 8-channel mixer with built-in VCA level CV inputs. You’ll find them on the official VCV Rack site. Instead of donations, Andrew prefers people purchase his modules, or buy the modules of other devs. All the modules are highly usable, with logical front-panel layouts and powerful CV control. Ed.: This in turn is encouraging, as it suggests a business model pathway for the developers of this unexpected runaway (initially) free hit. -PK

An open Music Thing module has come to VCV. The Turing Machine mkII by Music Thing Modular released by Stellare Modular – A classic looping random CV generator, typically used for lead melodies or basslines, sees a port into VCV Rack by a third-party dev. Open source hardware is being modeled and deployed in an open source environment.

There’s now Ableton Link support. A module supporting Ableton Link, the live jamming / wireless sync protocol for desktop and mobile software, is available via a module released by Stellare. In addition to letting you join in with any software supporting Link, there’s a very handy clock offset.

Reaktor to VCV. Michael Hetrick is porting over Euro Reakt stuff from Reaktor Blocks, and making new modules in the process. Especially worth pointing out is his Github page, which includes ideas on what to actually do with the modules in the context of a patch: https://github.com/mhetrick/hetrickcv

VCV meets monome. Michael Dewberry’s Monome Modules allow users to connect their monome Grid controllers, or use a virtual monome within Rack itself. He’s currently also got a build of Monome’s White Whale module: https://github.com/Dewb/monome-rack

Hora’s upper class tools and drums. Hora Music is to my knowledge the first “premium” price module release, at 40euro for his package of modules. With a combination of sequencers, mixers, and drums, it could be the basis of whole projects. See: https://gumroad.com/horamusic

I’ll be back next week with a few different recipes for ways you can make Rack part of your set-up, as well as a Q&A with the developer.

Ted Pallas is a producer and technologist based out of Chicago, Illinois. Find him at http://www.savag.es/

  • Seeing this project flourish reminds me that we live in wonderful times despite the weirdness around the world…

  • DPrty

    VCV is just great period.

  • chaircrusher

    Not to toot my own horn (too much) but I’ve been working with VCV Rack for about a week. What it’s done for me is give me an appreciate some of what Autechre was doing around the turn of the 21 century with Nord Modular and modular gear. These two tracks illustrate that — they have an algorithmic logic and pulse that’s off the standard grid of Western music.
    http://cornwarning.com/chaircrusher/Chaircrusher-GivenTheOption.mp3
    http://cornwarning.com/chaircrusher/Chaircrusher-VCV6.mp3

  • dalas v

    One thing I worry about is with so many developers, what if an update to VCV Rack causes modules to develop bugs? I’m really into the promise of VCV Rack, but worried that it will become a headache to maintain everything.

    • chaircrusher

      Since you have direct access to the developers you report bugs. The next release of Rack will have a package manager that will keep track of whether all your modules are up to date.

      In practice, VCV has been very stable for me, and I’ve not noticed much in the way of bugs in the 3rd party modules. Part of that is a testament to how easy the VCV framework is for a developer. Part of it is that what might be a bug may seem like just the way things are supposed to work!

  • QuinnH

    I’d love to use VCV Rack. But it makes the fans on my laptop (Macbook Pro 2015) start running after about two minutes and the computer gets warm. Is there something I can do to make it run better?

    • dré

      https://github.com/hholtmann/smcFanControl

      maybe get a cooling pad/stand for your laptop?

    • DPrty

      I’m on Window’s and it hardly hit’s the cpu at all.

    • papernoise

      Macbooks switch the cooling on when the processor is under heavy load and VCV does put quite a bit of load on it when you start to add some modules and patch them together. Does the same on mine.

      Second the suggestion of a cooling pad.

  • Among other platforms and tools, VCV Rack has prevented me from feeling too much Gear Acquisition Syndrome. In fact, when you can multiply the modules as much as you want, the limits of hardware modular feel a bit arbitrary. Sure, limits can help creativity. But it’s also useful to explore your own limits.
    VCV Rack is also pretty neat as a learning tool. Apart from the two Facebook groups (official and user-driven), the examples from PatchStorage are also quite inspiring.

    Can’t remember exactly when my first experiments with VCV Rack were, but it was probably in early September. Had played a bit with Automatonism and had great fun there. What’s really neat about Pd is that it’s supported on so much hardware, including the Raspberry Pi (and, via libPd, iOS and Android). It’s a bit hard to use for polyphony but, in my experience, it’s more stable than Max.

    Rack runs quite well on my 2012 MacBook Pro and 2011 Mac mini. Didn’t notice heat problems. My needs are relatively simple, which might be a big part of it. But that’s also about exploring your own limits.
    There’s been a bit of weirdness in the transition between 0.4 and 0.5, especially in terms of third-party plugins going where, supporting which version, depending on platform, etc. But the current update/upgrade scheme is more straightforward and robust.

    Been playing with many other things in the meantime, including Reaktor (bought it at the beginning of the sale). An advantage there is that there are Kadenze courses on it. Though community support on VCV Rack is pretty decent, having a bit more handholding can be great for those of us who weren’t already in the world of hardware modulars.
    And if you want to experience a really welcoming community of people who like to learn from one another by exploring all sorts of ways to do music with computers, Sonic Pi is really worth a try. It’s been the key to open all doors of digital musicking, for me. Deceptively simple, very powerful. Works like a charm on a Raspberry Pi (and it can run headless).

    With all of these things available, anyone can start musicking. Playing with music is as much fun as playing music and it can be a very deep learning experience.

  • R__W

    I’ve been using this since the 0.0 release. it still spins up the fan on my 2015 MacBook pro even with only 2 modules in use

  • TheVimFuego

    How did I miss this early(ish) Christmas present? It’s great! Runs well on my ancient laptop too. Will be using this as part of my mobile studio (mostly iOS these days). Will pony up for some modules too, got to support quality development.