Anyone who's had the pleasure of playing around with a synthesizer or dipping into sound design will be familiar with the oscillators, envelopes, filters and effects that comes built in by the manufacturer. But if you want more control over the architecture and makeup of your synth, you could set yourself up with a Eurorack: a physical rack for building your very own wall of Eurorack modules. Stack them up, link them via patch leads and essentially create and then recreate your very own custom synthesiser.
Different Eurorack Module Groups
Most Eurorack modules are so small that they'd fit in one hand, and a single Eurorack module is usually designed to do just one thing, which is exactly where its power lies. Just like you can make every word in the English language with just twenty-six letters, even with just a few simple Eurorack modules you can build a big and complex synthesizer.
Eurorack modules can be roughly divided into three groups: component modules, system-in-module and complete systems. You can use the search filters under module or complete system to browse specific groups:
Component Modules
A component module is a single Eurorack module that, on its own, doesn't really do all that much. These kinds of modules are like the individual pieces of your Eurorack puzzle, meaning that you need to combine a few of them to build the sonic picture.
System-in-Modules
A system-in module is a fairly complete synthesizer in one single module and can be used without even needing any other modules. While you don't get the array of options you would with a big module-stacked system, a system-in module is an easier solution when you want to add a synthesizer to your Eurorack without having to lose too much space.
Complete Systems
A complete system is basically a complete synthesizer that's often made up of separate component modules loaded into one rack frame - even if the model has a one-piece front plate. While the individual component modules that complete systems are built out of can be picked up separately, getting a complete all-in-one system is usually cheaper. This is the big difference between a system-in module and a complete system, since a system-in module is one single module rather than a cluster of component modules.
Euroracks: For the DIY Musician
Collaboration is the magic word when it comes to Euroracks, simply because you're putting together a range of different models that need to work together. Otherwise, nothing will make much sense. Euroracks are able to collaborate because they're coupled using patch leads. So a noise-generating module is fitted with an output for sending out the noise and by linking that output with the input of say, a filter, you can filter that noise and give it some shape before sending the result to your monitors or to an oscillator so you can play with the pitch. This is the freedom that Eurorack modules give you, and is exactly why Eurorack fans build giant structures of stacked modules linked with hundreds of patch leads. Of course, you don't have to go that far, but the beauty of Euroracks is that the more you add, the more you can do. The system is ideal for any DIY musicians as well as synthesizer-heads.
Build a Modular Synthesizer
Picking out different modules and setting them up so they can be linked in various different ways is referred to as modular synthesis. Famous synthesizers like the ARP 2600 are semi-modular, because the different patchable modules have been picked out by the manufacturer and can't be swapped out or moved around. Modular synthesis is nothing new, and already existed before the Minimoog came out and caused a synth revolution. Before the Minimoog, all synthesis was modular and experimental. It was also insanely expensive. So expensive, that it was often kept behind the doors of educational institutes - far from the reach of your average musician. These days, for a relatively small amount money, you can get a Eurorack frame or keyboard and get building a synth.
The Up-Side of Euroracks
There are quite a few advantages that come with using a Eurorack setup. The first is the cool-factor. Euroracks are a bit like a cockpit loaded with buttons, knobs and switches with a synth-head sitting at the helm. The second advantage is that you can't get any closer to sound synthesis than this, and you have complete, in-depth control over all of it. The third advantage has to be the price. A single module doesn't have to be all that expensive, so you can easily stack a few of them up. By parting with just a little of your pay cheque every month, you could end up with a twelve-strong rack by the end of the year. Basically, you can never have too many modules. Every single module will have a use, and since you can change up the order at will, you can build a different modular synth every day of the year.
The Down-Side of Euroracks
You're working with tangible hardware to build an experimental, DIY system so you can't save your work as files to be called up later. Of course, you could simply note down your settings or take a photo, so it's not all that different from saving the presets of a conventional all-in-one synthesizer - it just takes more time. Another disadvantage is that you will need a hefty stack of modules to be able to make a range of sounds. For example: if you wanted to replicate the capabilities of a Minimoog, you'd need at least ten to twenty modules. The non-existent polyphony of the system can also be a disadvantage. If you want to work with a polyphony of at least four, then you'll need four of each of your modules; make sure that everything is set to exactly the same value; and add a divider that sends the signal from your keyboard across identical paths. However, since most Eurorack-fans are more interested in creating less-than-conventional soundscapes than polyphony, the loss isn't so great. Basically, if you want the sound of a Minimoog, you'd be better off getting a Minimoog.
Frames, Racks, Cases, Power Supplies & Other Extras
The signals of a Eurorack system are called the CV signal (control voltage), and pressing the key of a keyboard is described by the term 'gate'. A CV signal can actually be anything: the frequency of an oscillator, the attack-rate of an envelope, or the cut-off of a filter. This is all Eurorack terminology that any fresh-faced synth-head might need to learn. Also, it's worth knowing that you can't just hook any keyboard up to a Eurorack system. You need a model that can send CV and gate signals. There are a few MIDI keyboards and synthesizers that can do this. There are also a few synthesizers or Eurorack-frame keyboards that have built-in racks for installing some Eurorack modules and most of the models will be MIDI and USB capable as well. If you'd rather keep things old-school, then you could go for a Eurorack frame, so you can install your modules and control them using a keyboard with simple CV and gate outputs. Just make sure to pick a rack that features power plugs for your modules - but this is usually stated in the name of the model. If you want to keep things simple and uncomplicated, then a specialised Eurorack keyboard is a great starting point for beginners.
Frequently Asked Questions About Eurorack Modules
What is a Eurorack?
By stacking Eurorack modules in a Eurorack, you can create a custom synthesizer that can be expanded and built on as much as you want. Simply mount your modules in a powered Eurorack frame and link them with patch leads.
