Image of an Arturia Synth

Building up a sound arsenal

In this post, we’re going to look at synth modules. You may have seen them. Small-ish boxes with lots of knobs and faders on them. They’re effectively the brain of the device, containing the sound producer and controls of the instrument. But the eagle-eyed among you will have noticed something crucial. There’s no keyboard attached. So how do you actually use them to make music?

Let’s take a look in this quick guide to using synth modules.

Elektron Digitone

Controlling voltage

At its most basic level, a synth module is a sound producer. Every synth, analog or otherwise, has some form of sound production capability involving oscillators, filters, amplitude control, and other components. The critical thing with synthesis is electricity. Everything a synthesizer does, from creating a sound to altering it, is done via manipulation of an electrical signal.

This is either controlled using analog methods, i.e. the signal is actual electricity, or digitally, where the synth recreates the effect of a ‘proper’ signal. Both have strengths and limitations. Analog sounds are accepted to be purer, and more sonically desirable, although require tuning and sporadic attention. Digital sounds are more precise, accurate and reliable, but lack some of the inherent warmth and depth of an analog signal.

In order to ‘play’ the synth, and create notes with it, the device needs some form of a control method. With analog synths, this involves using something called control voltage (CV), where the amount of electricity input at a specific stage of the chain has a direct impact on the sound. Imagine a synth with a keyboard attached; in this case, pressing a key increases or decreases the voltage being applied to the oscillator which, in turn, raises or lowers the pitch being output.

CV was the essential method used to control older synths, like those designed by Bob Moog in the 1960s. Its potential reached further than just music making too. It’s not unknown for synth users to have their units connected, via CV, to things like strobe lights, for example.

As the technology improved, so too the desire for a more modern control method grew. Enter the Musical Instrument Digital Interface standard. You probably know it better as MIDI. This advancement simplified control over synthesizers, and made it into something people without backgrounds in electrical engineering could get their heads around.

Behringer Deepmind 12D

What is a synth module

When a musician buys a synth module over a keyboard-equipped version, they’re effectively just buying the most important part of the machine; the part that makes (and changes) the sounds. Often a synth will have a signature sound that the user wants to access, or a specific application they’re looking to satisfy.

The majority of synths come complete with a full-sized keyboard integrated into the unit. This is clearly the quickest and easiest way to get up and running, yet it’s not always the answer for everybody. Imagine if your studio space is small, or if you already have a way of controlling the module. Adding another large, bulky, expensive synth/keyboard unit may not be desirable.

In these situations, synth modules are worth their weight in gold. By removing the keyboard element, you’re left with the actual value producer of the synth. And, importantly, you’ve not lost too much in the way of the physical footprint. The Behringer Deepmind range is a great example. If it’s the full synth experience you want, you have the option of either the Deepmind 6 or the Deepmind 12. Both operate using the same ‘brain’, and you can choose between 6 or 12 voices depending on what you need. Yet for those who already have a more established studio setup, there is the Behringer Deepmind 12D, which is just the actual synthesis module itself.

You’re still going to need a way to control it though. Sure, it looks nice when the lights are all flashing, but a synth module is near useless if you can’t actually use it to make music. Let’s take a look how you remedy that.

Arturia Keystep

Control freaks

The two methods we’ve discussed, CV and MIDI, both come to the fore here. CV, while trickier to get your head around initially, gives you higher potential resolution – ergo more possibilities. MIDI, on the other hand, is a bit more straightforward but slightly more limited.

Using CV – usually connected via mini-jacks – you can connect your synth module to other synths and have them control the main module. We’ve seen great examples of people connecting Korg Volca units to larger synth modules to give extra control over things like filters and LFOs. A synth like the Behringer Neutron is a veritable playground for this kind of experimentation. You have patches available to control everything from the delay speed to the filter cutoff, which gives you incredible potential for sonic mayhem.

Alternatively, you might consider having a ‘one keyboard to rule them all’ setup. We’ve had particular joy utilising a central MIDI controller like the Arturia Keystep as the hub for synth modules. There are a couple of ways to achieve this. One involves connecting the Keystep – which produces no sound itself – directly to the module using MIDI cables. The other makes use of an audio interface – we like the Focusrite Scarlett range – as a go-between.

Focusrite Scarlett 2i4

You also open up the possibility of incorporating your DAW software into the equation now. We tried out the Elektron Digitone using Ableton Live; the MIDI regions we created in Live were the output into the Digitone, allowing us to tweak sounds directly on the unit. This gave a far greater performance experience than using any combination of softsynths or plugins.

You can incorporate multiple synth modules using this method too even more simply by using USB control. MIDI over USB is now increasingly common, and is by far the most straightforward to set up. For studio setups its hard to see beyond this method, purely for its ‘set and forget’ benefits.


Once you get your head around the actual control of a synth module, you begin to see the benefits quite clearly. It’s possible to hook up multiple synth modules and create amazing workflows. You get the benefits of the different instruments yet without the space and financial burdens of having loads of full-sized keyboards clogging up your studio. Winner!

View our full range of synths on the Dawsons website.