Richard Devine modular synth
© Richard Devine
Music

How to build a modular synth – tips from the experts

Artists as diverse as Deadmau5, Coldplay and Mumdance have added a modular synthesizer to their musical arsenal – but how do you build the synth that suits your needs and budget? We ask the experts.
Written by Louis Pattison
16 min readPublished on
The world of modular synths can be intimidating to the beginner – in fact, even seasoned musicians have been known to blanche when faced with the prospect of a set-up that can basically do anything, providing that you have the money and the time to pour into it. But let's face it, isn’t that the appeal too?
One thing’s for sure: there has never been a better time to start building a modular synth. The burgeoning success of Eurorack – a universal modular format build with common jacks, cables and voltage, built to the same dimensions – means that it’s easier than ever to dive in and start building the synth of your dreams, mixing and matching modules from various manufacturers, knowing that it’ll all work together. Still, there’s an awful lot out there – from the familiar oscillators, filters and sequencers to more unusual modules by companies like Make Noise and The Harvestman.
Where do you start, without blowing four figures on some little boxes that might remain a stubborn mystery? Red Bull Music posed a few of the frequently asked questions about the world of modular to some of our favourite modular synth creators. Contributing to this article are:
  • Pip Williams of electronic trio London Modular Alliance and owner of Hackney store London Modular
  • Mumdance, DJ/producer and co-owner of Different Circles
  • Luke Abbott, London producer and one third of Szun Waves
  • Kaitlyn Aurelia Smith, Los Angeles-based Buchla composer
  • Richard Devine, Atlanta-based producer and software designer
  • Finlay Shakespeare, Bristol producer and composer signed to Editions Mego
  • Matt Robertson, musician, composer and musical director for Björk, Cinematic Orchestra and Anohni

What’s the first thing you need to know before you start buying modular synth gear – and what do you wish you knew before you got started?

Pip Williams: To start you’ll need a case with power, to house all your modules. This admittedly is a pretty boring topic but is often overlooked in the eagerness to just get buying modules to make sounds. An empty case alone is a substantial investment, so it’s wise to budget for this on top of what you’d planned for modules. Eurorack is addictive so it’s highly likely any space will be filled faster than you think. In our experience no customer has ever come in, a year down the line, and said ‘I wish I’d bought a smaller case…'
Mumdance: I would say it would be a good idea to have a good working knowledge of synthesis and signal flow before you start delving into modular. The initial learning curve is pretty steep so I would say it’s good to have a background knowledge of how synthesis works, be it with soft synths and VSTs or conventional hardware. I would also say don't buy too many modules at once. Get an initial system and master it, then slowly build it from there. Most modules these days are very deep and multi-purpose – you will benefit a lot more to know each module you own inside out before you purchase the next one.
Los Angeles-based Buchla composer Kaitlyn Aurelia Smith.

Kaitlyn Aurelia Smith

© Courtesy of Motormouthmedia

Remember to allow lots of time and space for listening, observing and discerning your reaction to sound
Kaitlyn Aurelia Smith
Finlay Shakespeare: I began building and using modular equipment in order to create interesting rhythm generators, which, in parallel, I had been designing in software environments. I soon found that the software was far easier to configure and control than the hardware counterparts I had been putting together, but in turn I had realised that the sound of some of the analogue circuitry I had been putting together was very powerful. I guess this is what I wish I had known from the start – modular synthesizers are, to me, like a palette of different colours. The wider the scope of shades you can create with the basic components you have, the more interesting your system will be to explore. Modular synthesizers will not give you a get-out-of-jail-free card for the creative process. They are an instrument, and as with most instruments, they take time to learn. Finding your own voice with these things takes time.
Richard Devine: You have to let go of the idea of it being this linear environment like a Digital Audio Workstation. Nothing happens on a timeline with most modular sequencers. You have to prepare yourself to be in a different mindset. If you can be open to experimentation and never holding on to anything, then the modular will be great for you. There are no presets or recalling sessions. It's like a sonic science experiment every time you begin a patch.
Kaitlyn Aurelia Smith: The only recommendation I have is to remember to allow lots of time and space for listening, observing and discerning your reaction to sound as well as your preference to what best describes the message you want to share with the world right now.

What’s a good set of basic modules to begin with?

Pip Williams: Depending on what you want the system to do, this varies a lot. A studio system, for example, would differ drastically from a gigging case. A studio case stays in one place and, presuming you have the space, can be larger, more comprehensive systems with modules that focus on doing fewer tasks very well. In contrast, a gigging case is smaller and needs to cram as much in as possible with feature-dense modules. The selection for each would be quite different. Doepfer’s range is great from an educational perspective. They may look basic, but combining a chunk of them together would get complex sounds, very quickly. We use many of their range for our beginner introduction courses at our store. They are no frills but make learning the basics so much easier.
Finlay Shakespeare: For a basic subtractive synthesizer set-up, you’d need, at least, an oscillator, a filter, a VCA and an envelope. However, this is not necessarily the best approach with modular systems – many subtractive synthesizers already exist and are really very good at what they do. What I typically recommend is only start with a handful of modules. I used to recommend Mutable Instruments’ Braids module as a great starter. It’s now been succeeded by Plaits, but has a similar principle at its core – it’s billed as a digital oscillator module, but can in fact behave as a fully-fledged synthesizer voice. It’s a good way of getting to grips with voltage control, and how to manipulate parameters using any signal to a user’s disposal.
Alongside Braids or Plaits, a nice analogue filter is always a winner. Frequency Central have some great clones of older Roland and Moog designs, which are still highly coveted for very good reason. An envelope is always a good idea too – the ALM Pip Slope is great as it’s physically small, but still playable, and has a great looping function.
Finlay Shakespeare

Finlay Shakespeare

© Fabio Lugaro

Try the whole process out in software first – it’ll save you many headaches when it comes to purchasing hardware.
Finlay Shakespeare
Matt Robertson: In my case, I started by trying to put together a ‘basic’ synthesiser in modular land, and so that meant a kind of classic setup of oscillator, filter, envelope and VCA. If you already have basic synths covered in your setup, then it maybe more interesting to get into modular sequencing and logic modules, since that’s something that rarely exists in “conventional” synths.
Mumdance: A lot of companies are starting to provide complete systems. I actually started with a Make Noise shared system which I found an excellent entry point into understanding everything. I have a pretty massive system now, but I actually think the most fun I was having with it was when I had a relatively small 6u system which I was pushing to its absolute limits.
Watch Mumdance make modular grime with AJ Tracey below.

Any advice for someone learning to patch?

Pip Williams: Generally, we advise people to start off slowly and really learn the modules inside out. Just having a nice filter and modulation source could be an easy way in and can immediately be used with your current set up in so many ways. The mindset for patching is different from set architecture synths. Starting out with simple patches, questioning the cause and effect of putting cables in certain jacks – deliberately forcing a module to try and do something it’s not necessarily designed to do – can achieve unexpected results. It also helps you to understand what’s going on in a much more tangible way.
Luke Abbott: It’s important to remember that it’s an open format instrument, so don’t get stuck in the case. Remember to try integrating audio or control signals from outside the case. The majority of how I use my modular synths involves other non-modular sources. For example, I often build hybrid instruments between the computer and the modular case. It’s fun to take a VST instrument, or audio recording, and send it into the modular case and see what you can do with it from there.
Richard Devine: Pick up Allen Strange’s book called Electronic Music: Systems, Techniques And Controls. I learned a lot about patching and also synthesis through this wonderful book. There are some great resources online as well. I would definitely sign up for an account at MuffWiggler.com. An amazing community of people that are friendly and there is a wealth of information there about learning how to patch up modular synthesizers there.
Finlay Shakespeare: Try the whole process out in software first – it’ll save you many headaches when it comes to purchasing hardware. I learnt on environments such as Native Instruments’ Reaktor, and Clavia’s Nord Modular G2 demo software – hopefully, some day soon, Clavia will realise that a G3 environment would be amazing. However, today, with the popularity of Eurorack, software such as VCV Rack has come into existence and is a great preparation tool for the world of modular.
Kaitlyn Aurelia Smith: There is no right way and there is no wrong way – the creativity is in your personal arrangement.

What are the key terms you need to learn – and what do they mean?

Pip Williams: Some more common terms.
  • Control Voltage – Often abbreviated to CV. This is a variable voltage signal that is used to control behaviours ranging from the pitch of oscillators to the cutoff setting of filters and more.
  • Gates – A gate is a burst of 5v that is held when the gate is high and when the gate is released the voltage returns to 0v.
  • Trigger – A short burst of 5v usually used to trigger an event in time. For example to trigger an AD/AR envelope.
  • VCA – A Voltage Controlled Amplifier controls the amplitude of a signal passing through it by scaling or attenuating it in response to a separate control voltage input. Typically used at the end stage of a patch. However a VCA doesn’t just need to be used for controlling an audio signal. They're handy for controlling modulations and/or triggers etc
  • Envelopes – The envelope generator (EG) module is most commonly used to shape the loudness, or dynamics, of a note when connected to a VCA (Voltage Controlled Amplifier). However, they are very useful as a modulation source for controlling other aspects of your patch. Envelopes are usually described in terms of stages, a typical four stage envelope has an Attack stage, a Decay, a Sustain and a Release Stage.
There are often times when there’s a sea of cables staring at you, but if you understand the basics of what’s controlling what, you’ll be able to retrace your steps, make tweaks and add to what you already have.

Any companies in particular that you recommend?

Pip Williams: There are so many manufacturers now. The bar is being raised significantly which is great for the user. We’ve only really sold modules which we know we would use personally and could truly recommend to customers. Being a physical store and having the opportunity to try gear out on a daily basis, it quickly becomes clear which will be popular. Substandard products just fade away. If we were put on the spot, we’ve always been huge fans of Mutable Instruments, ALM Busy Circuits and Mannequins. In more recent months, SOMA and Instruo are putting out some excellent bits.
Luke Abbott live with Szun Waves

Luke Abbott live with Szun Waves

© Press

Luke Abbot: I really like the Doepfer a-124 Wasp filter – it’s a very cheap filter module but absolutely one my favourite sounding filters. It saturates in interesting ways and can add a lot of character to an audio signal. I also really like vactrol low pass gates – the Make Noise QMMG is a favourite of mine.
Finlay Shakespeare: The way I see the world of modular synthesizers is that every brand has a certain character, much like how independent record labels often behave. You have brands such as Industrial Music Electronics (aka The Harvestman) designing amazingly gritty-but-musical digital modules which always sound incredible, through to Instruo, where their analogue designs are super smooth and, in the world of synthesis, classic-sounding. I say all this because I don’t feel that I can really recommend any and that be of any use – once a modular user starts exploring the marketplace, they will find brands that resonate with them.
Matt Robertson: I really like Analogue Solutions Modules. Straight forward, lots of attenuators, great to learn stuff on, and sound good! Make Noise modules are a bit more esoteric, but also sound great and encourage experimentation!
Mumdance demonstrates a modular synth

Mumdance demonstrates a modular synth

© James North

Mumdance: I’m slightly biased, but my favourite company by far is ALM Busy Circuits. It’s a UK company based not too far from where I live, and I have become good friends with the owner Matthew. Last year we worked together to release the "MUM M8” which is a recreation of a filter from an Akai S950 Sampler – a unit which is very prominent in pretty much all of my productions and also a very pivotal piece of equipment which was used to make a lot of early UK breakbeat hardcore and jungle records. The Akai S950 filter has a very specific resonant sweep sound which is instantly recognisable. We used the same chip which was used in the original filter, but added resonance control, saturation and a VCA. I feel very happy to have helped add in my own small way to the Eurorack canon.

Is there a particular module that you’ve bought that has transformed what you do?

Pip Williams: To be honest, every new module you buy should open up your system in new and exciting ways. It can free up others to concentrate on different tasks and generally just breaks up the way you’ve been patching previously. It’s really easy to be drawn to the sexier modules; Oscillators, nice filters, complex sequencers and effects. All these provide instant gratification as the results are right there to be heard. But it’s adding utilities that can often have the most significant changes. Never underestimate switches and matrix mixers!
Finlay Shakespeare: Livewire’s Audio Frequency Generator oscillator and The Harvestman’s Tyme Sefari digital audio buffer were the two modules that really made me take notice of Eurorack - I had been building a 5U system beforehand. The Tyme Sefari in particular always gets used on everything all the time. In my recent work, I’ve fed my vocal mic through our own FSS TG5 pre-amp, into the Tyme Sefari, then had the TG5 controlling the various record, direction and loop points of the Sefari. I can sync the Sefari up to my drum machine, and have cut-up vocal loops being assembled and played back in a rhythmic manner. Also, there’s an expander module which allows for the digital buffer to be glitched out, and that adds a whole other level to the Sefari’s playability.
Richard Devine: For me it would be the Orthogonal Devices ER-301 Voltage Controllable module, which is a canvas for digital signal processing algorithms. It's been a complete game changer for me. You can completely customize your own DSP blocks into units that can accept CV and gate signals at any point in the chain. It's like having the best of both worlds in one little spot. I have pretty much built my entire live show around this module alone.
Richard Devine at work in the studio

Richard Devine at work in the studio

© Press

What’s the best thing about modular synths?

Pip Williams: The best thing is how open-ended everything is and the freedom of possibility it holds. This can also be the worst thing too because you may never feel that your system is complete. But that’s a nice luxury to have. And having a total hands-on experience is infinitely more enjoyable and productive than using a mouse.
Luke Abbott: It’s a way of working that becomes highly personalised to each user. I’ve recently shrunk my system down from five cases to three, each one has a very defined purpose. As a working musician it’s important for me to think about workflow and productivity. I wouldn’t say that the modular synth is the main part of my studio, but I do like how it can facilitate and encourage a very hybridised way of working and how it can become an extension of other instruments. It's fantastic that there are so many manufactures who have embraced CV, it's such a flexible standard to work with.
Finlay Shakespeare: The fact that, theoretically, each person’s system is their own, completely unique and individual. Modular synthesis should be like musical lego, and will probably unleash some sort of child-like freedom to explore various avenues within sound design. Also, the funny looks you’ll get walking around town with an open modular case.

Anything in particular to watch out for?

Luke Abbott: Modular synths should come with a stern warning. I heard someone describe modular synths as being like ‘a personal money bin’. I’ve also heard them described as ‘a black hole that sucks in money’. If you get seriously into it, it can get pretty expensive. And it’s not necessarily the best use of your money either, there are more cost effective and more pragmatic ways of making electronic music without having to go down the hardware modular rabbit hole. It can be a pain in the arse to tour with a modular case too, especially if you fly a lot.
Pip Williams: A lot of newcomers getting into modular have done plenty of research online about manufacturers and module functions, but haven’t fully thought through what it is they want the system to do and how to integrate it with their current setup. The last thing you want is to part with all your savings and be underwhelmed and disappointed that it doesn’t do what you expected. For this reason, it really is worthwhile going somewhere – preferably to London Modular of course! – to test out everything before you buy to avoid any rash decisions.
Mumdance: If you are lucky enough to live in reach of an actual shop which sells modular equipment, go down to the shop and make friends with the people who work there, who are always very friendly and knowledgable. They will be more than happy to demo a module for you if it's in stock. I usually shop at London Modular or Rubadub, and they have both helped me so much with advice and help, trouble shooting and with planning my system.
Finlay Shakespeare: Always check the red stripe.
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