There’s been a significant rise in the numbers of people wanting to step away from their computer-based music production systems.

Maybe you’ve experienced it yourself; staring blankly at an empty Ableton Live screen, with access to any sound you could think of (albeit virtually), yet missing that physical connection with an instrument.

Or perhaps you have a collection of ‘regular’ instruments but have always dreamt of mixing and matching different elements of each to create something totally unique to you and your musical style or workflow.

Portable Travel Case Light Blue

Step forward, modular synthesis. Or, in this instance, step forward Eurorack. But what exactly is Eurorack, and why are so many people flocking to these scary banks of wires and flashing lights? In this guide we’ll walk you through your first steps into the strange, exciting world of Eurorack modular synths, offering recommendations on where to start, what you can do with modular and the gear you’ll need to do it.

 

In the beginning…

Modular synths don’t carry the same levels of intimidation they once did, and that’s largely down to the introduction of the Eurorack format in the 1990s.

Before Eurorack, building a modular synth demanded an understanding of electronics and engineering on top of whatever musical ability you had, making it nigh-on impossible – not to mention eye-wateringly expensive – to get into. Put simply, one did not ‘dabble’ in modular before Eurorack. Modular was – and still is, to some extent – a very serious business.

The introduction of the Eurorack format went a long way to breaking down those walls. It was Dieter Doepfer, a German physics graduate, who led the way by creating a standardised set of ‘rules’ regarding the physical dimensions of individual modules based on the existing standards used for rack-mounted audio/visual equipment. So, module heights were standardised (Eurorack is 3U), and module widths were given a measurement unit – HP.

This new common method of measurement gave equipment manufacturers, and their customers, confidence that gear from different brands would play nicely together, and would be cheaper to produce, thus Eurorack became the de-facto standard for modular synths.

How do they work?

Modular synths operate by manipulating audio or control voltage (CV). Essentially, you pipe an electrical current in one end, feed it through different modules, and it comes out the other end as an audio signal. Along the way, that electrical signal will power an oscillator, which will alter the electrical signal to make it audible to the human ear. You might then send it to a filter to sculpt the sound, or to an envelope to change how the sound reacts across time, or to an effects unit to colour it. And while all of this is going on, you may have separate CV sources affecting the parameters of each individual component, as a form of automation.

It’s here you start to see the true beauty of modular synths, and of Eurorack. You see, whatever system you have, and whichever modules make that system up, is entirely up to you. You’re effectively creating your own utterly unique, completely bespoke musical instrument. Want something ultra-basic to complement your existing synth collection? No problem. Want an effects unit you can feed your guitar into? Fine! Want an entire live performance rig you can carry in a suitcase? Sure! With modular synths, and Eurorack, the only limit really is your own imagination.

Where do you start?

Before you go ploughing your hard-earned cash into loads of modules, it is highly advisable you immerse yourself in the wider world of modular synthesis. Learn the language, identify what you want to do, and let your mind run free with the sonic potential on offer. Eurorack modular synths are wonderful things, but they’re not without a learning curve. You’ll come across terminology and applications that will baffle you, at least initially. Learning modular is a commitment, that’s for sure, but it’s a hugely rewarding one.

A good place to start is YouTube. We’re big fans of mylarmelodies and DivKid, both of whom take the complex world of modular and explain it in a way that newbies can understand. We’d also highly recommend the Patch & Tweak book by Kim Bjorn and Chris Meyer, which clearly explains the concepts and terminology behind modular sound design. Finally, one of the best online resources for Eurorack users is Modular Grid, which lets you plan out your dream Eurorack setup and gives you accurate information regarding modules sizes, functionalities and cost.

Eurorack Gear Guide

With all that in mind, let’s take a look at some of the gear you’ll need to get started with Eurorack. Bear in mind, it is extremely easy to go crazy and order all manner of shiny, exciting equipment at this stage. Trust us, we’ve all been there. It’s always better to start with a clear idea of what you’re trying to achieve, and going from there.

Cases and Power

It might not be the glamorous side of modular, but a good quality case and reliable power supply are two of the most important elements of any Eurorack rig. As mentioned earlier, Eurorack module height is 3U, so a single row is 3U, two rows is 6U etc.

Case width – measured in HP – is entirely variable, depending on how many modules a user wishes to install. It’s generally accepted that, for a beginner, you’ll want room to grow into a case. Starting small may seem sensible, but most users find themselves (and their growing collection of modules) quickly demands a larger case.

For us, the Graham Eurorack case is a solid bet for your first Eurorack case. Its two rows mean you’ll have plenty of space for modules, while the option to have a power supply pre-installed takes away some of the hassle.

Speaking of power, you’ll need to ensure your case – whatever it may be – has enough juice to power your modules. Essentially, you’ll need a power supply module and ‘bus boards’, into which you connect the modules. Modular Grid is a useful resource here, allowing you to check your power supply has enough availability to power your selected modules. 

Modules

As the building blocks of your sound, the modules you choose will be responsible for realising your creative vision. No pressure, then. Thankfully choosing, and playing, modules is where the real fun begins. An empty case is a blank canvas, waiting to be filled. Be warned though; you do need to consider every part of the signal chain. With modular, you really are starting from scratch. Let’s take a look at some of the best Eurorack modules out there today.

Voltage Controller Oscillators (VCOs)

Oscillators are the foundation of any synth patch. They come in different shapes and sizes, with different tricks and tools to play with, but at a basic level they provide you with a source of sound. We’re big fans of ALM/Busy Circuits’ MCO, which is a relatively lightweight oscillator with plenty of potential for modulation. For more variety, it’s hard to look beyond Mutable Instruments’ Plaits, which offers an incredible number of different voices, from synths to drums, with a good dash of weirdness thrown in for good measure.

Modulation

Modulation is the simple act of changing, altering or manipulating an audio or CV signal to make it react differently. Guitarists will be familiar with tremolo or phaser effects, which change a signal over time. Modulation in Eurorack acts in the same method, only with way, way, way more creative potential. You could use envelopes to shape the volume of an oscillator, or low-frequency oscillators (LFOs) to automate the opening and closing of a filter. When starting out, it can be easy to feel overwhelmed with the options available to you. We’d suggest starting simple with a couple of basic modules, like the Doepfer A-145 LFO generator and the Erica Synths Pico EG, for example, and progressing from there once you understand the application.

Filters

Filters are primarily tasked with shaping the sound being output from your oscillator. They do this by using equalisation; a ‘low pass’ filter will allow any signal under a predetermined level pass, while heavily reducing the volume of anything over that limit. Similarly, a ‘high pass’ filter allows higher frequency sounds through and attenuates frequencies below the limit. A ‘band pass’, on the other hand, does the job of both, allowing frequencies within a specific section of the spectrum through.
Experienced users tend to have their own favourite filters, often due to their association with vintage synths and the way they colour the sound. For Eurorack beginners, we’d recommend the TipTop Audio Forbidden Planet, on account of its ability to filter separate signals simultaneously, and the fact it sounds amazing.

Voltage Controlled Amplifiers (VCAs)

Hang around in the modular world for any amount of time, and you’ll be guaranteed to hear the phrase “you can never have too many VCAs.” Despite their unglamorous nature, VCAs are crucial to setting the level of signal going from one module to another. As an example, you might plug your VCO into the VCA, and then the VCA into your output device. Using the CV input on the VCA, you could connect an LFO which would modulate the volume of the signal akin to using a tremolo pedal. Alternatively, you might connect an envelope generator to the VCA and have it provide attack, decay and sustain characteristics.
For a starter system, we’d recommend something like the After Later DVCA, or the 2HP VCA. Both modules will provide that basic connection you’ll need, while the After Later model – based on a classic Mutable Instruments design – also allows you to choose whether the VCA responds in a linear or exponential manner. In simple terms, does it reach full volume at a steady rate, or does it ‘slope’ upwards.

Sequencers

A sequencer does the job of ‘playing’ a modular synth. If you’ve used a DAW, or perhaps a drum machine, you’ll be familiar with how they operate. Essentially, you input the steps you want to play and the sequencer, via a clock, plays them at whatever tempo you’ve set. Step sequencers are arguably the easiest to get to grips with for beginners, offering real-time feedback over what’s being played and where. The Intellijel Steppy is a great choice here, offering one of the simplest and most intuitive sequencer workflows we’ve come across.

It’s worth noting that not every sequencer offers control over pitch, so programming notes or melody lines may require a separate quantizer module. These take the incoming CV signal and round it up or down to within a pre-determined musical scale. The Intellijel Scales module does a great job of this, and allows you to save patterns for future use – great for live performance.

Utilities

At first glance, utility modules aren’t the most exciting. It’s a broad term to cover many different sub-genres of module, but basically utility modules exist to help you get the most out of your more obviously exciting modules. It could be that they split or multiply incoming CV signals ready to be routed elsewhere. Or they might tame a wild CV signal before it reaches the next module. What they lack in glamour, they more than make up for in sheer usefulness.

It says a lot that one of the all-time most popular Eurorack modules in Make Noise Maths. While nominally classed as a function generator, the list of things Maths does wouldn’t fit on this page so you can see why there are lots of modular users who couldn’t live without it. Plus, who wouldn’t want an LFO that can take up to 25 minutes to cycle? We’re also big fans of Pamela’s New Workout, from ALM/Busy Circuits, which has a similarly long list of features and functions and excels at making your other modules look (and sound) good.

Effects

Rounding off the list is effects. Again, guitarists will be more than familiar with effects and what they bring to the table. In Eurorack, there is a whole other world of experimentation on offer thanks to the fact you can automate parameters using CV. At a basic level, there are the usual delays, reverbs, distortions and modulators, along with a whole host of things you’d never considered. For beginners, we’d suggest seeking out a well-stocked multi-FX module like the TipTop Audio Z5000, which packs in 24 different reverbs, delays, modulation and harmonisation effects.

Conclusion

We hope this guide to starting off in Eurorack has been helpful. It’s a crazy, complex, vibrant and exciting way to create music, and one with the potential to change the way you approach your craft. Sure, there’s a lot to learn, but the modular community is friendly and helpful, and there are plenty of resources available to support you in your quest for knowledge.

The most important thing, however, is to have fun. Don’t get bogged down in trying to understand the difference between an attenuator and an attenuverter, or in trying to make sense of Turing machines; all of that will come naturally the more you invest yourself into Eurorack. And you should. Invest yourself, that is. Seeing a cable-free bank of modules, blinking away, waiting for you to begin patching is immensely exciting. In a world of safe, sensible music, modular synths give you the chance to unleash chaos. And that is why we love them, and think you will too.