Getting started with eurorack modular synths

Around a year ago I got started building my own modular synth. Putting together your own unique instrument with a range of modules seems to be increasingly popular amongst electronic musicians, for a range of reasons I blogged about recently. Everyone is aiming for something different, and although there are plenty of reviews of individual modules out there I have found less overviews of what people are trying to achieve with their systems and how they try to get there. Here I’m sharing my story, hopefully it’s interesting to read not just what modules I chose, but why and how that thinking developed. Inevitably it’s hard to get away from describing particular modules, but I’ve approached this in terms of the thinking rather than the specific equipment as much as I can.

Starting semi-modular

Recently I’ve been trying to explore new processes in order to continue to develop my music and production. Some of this has involved digging deeper into music theory and learning piano, some exploring different production techniques. I started off producing music with hardware many years ago, and having ended up almost entirely ‘in the box’ of my computer I wanted to add back the immediacy and experimentation you get with dedicated hardware. I got hold of an Access Virus, and was looking for other hardware that might have an interesting influence on my process and sound when I came across the Make Noise 0 Coast in this video from Mylar Melodies. I love the Virus, but there are tons of software synths that take a very similar approach and have a similar sound palette, but the 0 Coast really seemed to be something different. This got me started looking at eurorack modular gear, and getting excited to explore different processes for making music.

Starting a case

I loved the 0 Coast, and started making some sounds that I never would have discovered with my existing synths. I’ve owned and used many synths over the years, but this was the first bona fide analogue synth I’d owned, and the heavy sounds it produced made me wonder if there was something in the old analogue vs digital debate. It certainly seemed to make basslines that really shook the room without any additional processing, and leads that cut through and sat in their own space in a mix. One thing the 0 Coast lacks is a filter, and although this is part of its unusual charm I wanted to see what adding one would do, so it was time to explore getting some full blown eurorack gear.

I’ve no shortage of filters in my computer and other gear, so I wanted to go for something more esoteric. I went for the Wasp filter, which is at the same time esoteric by the standards of the non eurorack world but also quite ubiquitous among modular enthusiasts. It was a good choice, giving the 0 Coast the option of a filtered sound, but with some really odd behaviour that makes it sound quite unique. Cranking up the input and resonance while sweeping the cutoff produces an uneven and at times downright strange sound.

Before I could make use of this though I needed a rack. I picked up a small 84hp single row rack made by SynthRacks, and a second hand GMSN pure power module to sit in this rack and power it. I went for this small and relatively cheap option because at the time I was seeing it as containing ‘accessories’ for the 0 Coast. A larger rack seemed a lot of money to put into this, and a big commitment. I did end up selling this small rack and buying a TipTop Mantis on eBay. If you are sure you want to explore modular in a meaningful way it probably would be better to buy a larger case first.

Sequencing and random ideas

Having played around and made some tracks using the 0 Coast and the filter I was getting really interested in the potential for patching to take different approaches to composing music. I found myself using the random functions on the 0 Coast to generate things that were really unexpected. I also started to see how you could use things like LFOs to not just change the timbre but manipulate the rhythm quite differently to traditional keyboard playing or on screen MIDI programming. At this point I started to discover YouTube videos of eurorack sequencers like the Music Thing Modular Turing Machine and Intellijel Metropolis. I decided that what I most wanted my modular to be was a machine for inspiration, not for making whole tracks or getting away from my existing processes, but for adding unexpected sequences and ideas that I wouldn’t otherwise come up with.

Seeing just how many modules were out there I decided I needed a focus to make something really useful, so I focused on sequencing, and particularly sequencing that would give me different workflows and ideas. My thinking was that it was experimenting with sequencing that would give me the inspiring new ideas that I wanted to get out of modular, rather than taking a more sound design focus.

The first sequencer I bought was the Intellijel Metropolis, which uses sliders and ‘pulse count’ switches to design sequences. I came up with some great ideas using such a different approach to piano roll grids, and found a lot of inspiration in the random mode. Wanting to explore random more I bought a Turing Machine random sequence generator, and soon after built the Volts and Pulses expander. What I liked about the Turing Machine was it’s complete randomness, but the fact that if it spits out something you like you can loop it. The Volts expander also lets you edit the sequence in a rudimental way by tweaking some of the notes it hits and not others. I quickly needed a quantiser as the voltages from the Turing Machine don’t correspond to any musical scales, so I built the Sonic Potions Penrose. A few mistakes on my part made this a difficult module to build, but it was well worth it. It not only allowed me to use the Turing Machine musically, but I also discovered the potential of feeding it any voltage sources and turning them into something musically useful.

This was a real penny drop for me — the fact that even modules in my system like the LFO in the 0 Coast that I previously considered only for shaping sound could be used to generate the musical sequences that I was building the modular for. An LFO itself might produce only up and down sequences of notes, but modulate it’s time with an envelope or another source of CV and suddenly the line between sound design and musical sequences becomes very blurred. I hadn’t appreciated until then how the way eurorack systems separate pitch information, modulation and timing events in ways that can be crossed over and musically combined gives so many possibilities for working with music differently to conventional DAWs or sequencers.

From that point I knew building this instrument was really exciting, and I expanded to building another simple sequencer to modular my Metropolis (and other modules), and picked up a Mutable Instruments Marbles to further explore the manipulation of randomly generated sequences.

DIY modules

As I was exploring sequencing I also discovered DIY module kits, mainly because the Turing Machine is only available as one. I did some electronics in school so was fairly familiar with a soldering iron and thought I would give it a go. I actually got a Turing Machine second hand from someone who had built it themselves in the end, but since then I’ve built quite a few modules. If you enjoy doing it then it can save a bit of money, and give you access to modules you can’t get any other way. If you don’t enjoy it then steer well clear — it can take up a lot of time and produce a lot of frustration. I’d rather be making music than debugging electronics, so I’ve decided to stick to just putting together simple modules, and those which are analogue which are a lot easier to debug than digital ones.

Exploring sound design

After exploring sequencing for a while and understanding the blurring between sequencing and sound design I decided to build out my modular with some other more sound focused modules. I had bought a TipTop Mantis case by this point and so planned pretty carefully how I wanted to fill the remaining space in it using ModularGrid. I decided to rack mount my 0 Coast for a while (see my tutorial here) to keep everything together in one case.

I wanted another analogue oscillator to explore the warm and heavy sounds this could produce, so built a Befaco Even VCO. I also wanted a different filter, so I built a Humpback Filter. I picked up a small mixer to combine these with my 0 Coast, and started to realise I might need a VCA to control the volume of sounds and modulation so built a 6 way VCA from Zlob Modular. This gave me lots more options for sound, including the classic analogue-sawtooth-through-low-pass-filter that you can’t help but love. For some more complex sounds I got hold of the Mutable Instruments Plaits, as it seemed like a comprehensive way of really building out the sounds I could make in a small space.

Modulation and utilities

By this point I could produce some really interesting sequences, and had some powerful building blocks for sound, but the single envelope and single LFO in my 0 Coast were under heavy use, and despite getting some mileage from splitting their outputs and feeding to different things I thought I was missing some more modulation sources. By this time my case was getting pretty full, so I wanted to get a module that would provide lots of modulation in a small space. There’s lots of ways to do this, but I decided the Mutable Instruments Stages would work well for me as it provides several LFOs or envelopes, and can be patched to itself to create some interesting other kinds of modulation.

I had plenty of VCAs to manipulate my modulation in interesting ways, but I quickly realised at this point that I was really short of other utilities for using it in the way I wanted. I particularly needed some ways of adjusting the intensity of the LFOs and envelopes coming out of the Stages, and also found I was getting a lit of use from the single attenuvertor in the 0 Coast. For that reason I decided to build a Befaco Dual Attenuvertor which I had played with in VCV rack, and a Pusherman Levels (4 way attenuator). Along with the VCA these let me control all that CV and start to really explore getting complex and moving sounds out of my system.

I picked up a few other things along the way. Early on I got a Disting and this multifunction module was great for exploring what I might need next. It let me try out lots of different functions and see which I used the most, and would be worth getting dedicated modules for. I also built a Music Think Modular Chord Organ, originally to play with chords but I ended up preferring the Radio Music firmware which turns it into a simple sampler. My last 2 hp was filled with a dual manual switch, which is interesting for shifting between sequences from my various sequencers.

The complete case

The now full case is working well, and I’m glad I put so much thought into what I wanted to achieve with it. It’s broadly got about a row of sound design based modules, and a row of sequencing modules with a bit of modulation. As a machine for exploring new ideas, random sequences, and inspiring ideas I can then write around with the rest of my gear it works really well. There’s plenty of other sound design possibilities I’d like to explore at some point, but for now it provides me with the inspiration and experimentation I was after when I first got into modular synths.

I’d encourage anyone interested in getting into eurorack synths to take a similar process. Experiment a little, but figure out what you want to achieve and put plenty of thought into the modules you need to get there. The nature of these synths is that they can be more than the sum of their parts, and the potential of many modules need to be unlocked with the right complementary modules. Getting the right utilities is also really important, so put plenty of thought into these less exciting modules that make your case a system rather than just a collection of modules.

View my modular in more detail at modulargrid.


Originally published at Mentat.