A Simple Guide to Modular Synthesis With VCV Rack

Modular synthesis is an incredibly powerful method of electronic music production that emphasizes patching and routing, where the audio and control voltage (CV) paths are completely modular and can be rearranged and interchanged to create a ton of different sounds. A modular synth is usually composed of a few ‘modules’ such as oscillators, filters, and voltage-controlled amplifiers (VCAs) that are wired together in a ‘patch’ and controlled via a ‘CV’ or ‘gate’ system.

Modular synthesizer systems are built to be versatile and powerful, and thus can take up a LOT of physical space due to the size of the modules, and all of the cables needed for patch points. Although these synthesizers have been around for decades – and are still popular – many people aren’t familiar with them because of their steep learning curve, their need for a lot of physical space, and their fairly exorbitant costs.

Modular synths can take up an enormous amount of physical space

Yes, modular synthesizers are complicated beasts. But what if you don’t want the hassle of patching and all that other stuff? What if you just want to play around with some awesome sounds and experiment with some unique modules without having to learn a bunch of routing tricks or other CV techniques?

What if you just want to play around with some awesome sounds?

You’d probably love to have a modular synth that comes pre-built with everything integrated, and ready to go. Thankfully, there is such a thing as ‘modular synthesis in a rack’. With VCV Rack, a compact modular software synthesizer, you can get your hands on some pretty amazing signal processing and sound manipulation tools that would usually require multiple physical units (and rack space!) to achieve the same results. In this article, I’ll explain exactly what VCV Rack is and why it’s so great for modular lovers – beginners and experts alike – who don’t want all the complexity and cost associated with real hardware modulars.

VCV Rack

VCV Rack is a compact modular software synthesizer that aims to make modular synthesis approachable and accessible to a broader audience. Instead of using a patch system and CV, it uses a simple software interface that is pre-built with modules that can be easily rearranged, removed, and replaced with different effects and synthesizer tools.

As the name suggests, VCV Rack is a software modular synth. This means that instead of using physical hardware, you plug modules into a software interface and patch them together in a chain. This allows you to rearrange and adjust your chain of modules at any time without having to physically re-route or re-patch cables. While this may sound a bit limiting, VCV Rack has a lot of benefits:

  • You can use any audio interface
  • You don’t have to buy or find space for a modular audio interface
  • You can use any audio interface that supports ASIO or Core Audio (in other words, it works on both Windows and Mac)
  • You can easily add modules or change the order of your chain at any time.
  • Easy to share patches; if you make a cool patch, it’s super easy to share it with others
  • VCV Rack 2 Free is open-source

All your favorite modules are here!

Setting up VCV Rack is quick and simple. Once you’ve installed the software, you’ll want to ensure that your audio interface is set up correctly, which you can do through the Audio module on your rack. When you’ve set up your audio interface correctly, you can start adding modules to your chain! To do this, right-click on any empty area in your rack. A menu will pop up with a list of modules you can add to that slot.

You can add as many modules as you’d like. While most of the modules are self-explanatory, here’s a list of some of the more common ones:

  • VCO – This is a basic oscillator for creating basic sine and triangle waves.
  • Noise – This generates a noisy signal at a specific frequency.
  • ADSR and ENV – These are standard ADSR (attack,  decay, sustain, and release) and ENV (envelope) modules that can be used to control the volume of a signal.
  • LFO – This low-frequency oscillator can be used to control the speed of other parameters.
  • Delay – These modules can be used to create echo effects and reverberation.
  • Mix – This is a simple mixer that can be used to blend two audio signals together
  • Filters – There are low-pass, band-pass, and high-pass filters available.

You can also re-arrange the order of the modules by clicking and dragging them around the chain.

A sample VCV Rack patch


Modular synthesis is an incredibly powerful and flexible method of electronic music production that allows you to create almost any sound you can imagine. However, it can be quite daunting due to the complexity of physical modular systems. VCV Rack is a great modular synthesizer for beginners who want to experiment with modular synthesis without the complexity. With VCV Rack, you can use a simple software interface to easily add and arrange modules and effects, without having to deal with patching and routing.