Modal CRAFTsynth kit review – more than 10 minutes of happiness?

Modal’s CRAFTsynth is as easy to put together as a Kinder toy. The surprise is, you’ll still be playing with it months later…

  • Low cost ‘DIY’ synth that anyone can assemble
  • More versatile than many ‘cheap’ synths, genuinely usable sound
  • Powerful editor app for desktop and smartphone

Modal CRAFTsynth DIY: £79/£45 (Gear4Music)

After putting together a roundup of synth kits, it seemed ridiculous to be faced with a £45 kit and not just buy one to build. In fact, for the original £79 price, Gear4Music are selling a bundle of Modal’s CRAFT synth and drum machine kits…

So, I did – and here’s what the Modal CRAFTsynth is like. The original, not the shiny-white 2.0

The Modal CRAFTsynth 1.0 DIY kit (1.0 because there's a 1.0)...

Modal’s CRAFTsynth sits in a very unusual position in the world of cheap fun electronic instruments – its on-paper specs wouldn’t go amiss in a £200+ mini-key monosynth, particularly if it was analogue, but it’s a DSP-driven virtual analogue. It’s got a powerful synth engine, but talks to the world via 8 knobs, five capacitive buttons and just two outputs – headphone and line out – with a USB port for power, MIDI and everything else.

Unlike the single-board Teenage Engineering Pocket Operator synths, you assemble it. Unlike most sub-£100 (and more expensive, too) DIY synths, you don’t need to go near solder.

It’s the synth equivalent of those polystyrene planes you could buy in the ’80s – the thin paper packets containing a build process far simpler than any Airfix model, but unlike the plastic models, they actually flew and could be played with right away.

In short, the CRAFTsynth is a kit that provides instant gratification in terms of build and playing right away – for many people, particularly gift-hunters, that would be enough. Does it offer more than just the joy of assembly?

CRAFTsynth build guide – barely worth writing!

Unpacking the CRAFTsynth, the idea was to document the build process in much the same way as the Recesky camera kit – but it honestly has taken longer to upload the images than it has to build the synth. The kit’s really well packaged, with everything laid out for easy identification.

Modal CRAFTsynth kit

Five PCBs slot together, secured by jumper blocks, and then you attach the shafts for the eight rotary pots and put some rubber grip strips on the side.

The instructions are clear and simple, and it’s well within the ability of anyone who can thread a needle, change a jumper on a hard disc or assemble small Lego parts.

The electronics are exposed, so some common sense is needed, but it’s brilliantly executed. There’s even a serial number space for you to personalise your synth.

CRAFTsynth DIY battery connector

Once assembled, you need to power it up – a USB power bank, or the Adafruit ADA727 (£5.75 on Amazon UK) 3 x AAA battery holder can be connected, the latter leaving the USB port free to connect to devices that can’t provide enough power for the CRAFTsynth.

The same format of boards and construction is used for the CRAFTrhythm.

How does it sound?

  • Digital oscillators are crystal-clear
  • Delay effect adds useful depth, distortion is very user-friendly
  • Very flexible sound shaping for the price

In a nutshell, the CRAFTsynth’s sound is clean. Clean like a laboratory experiment in producing the most ideal waveforms and getting them from oscillator to audio with the least disruption ever. I suppose, if you look at the board, that shouldn’t be a surprise – but so many inexpensive synths and gadgets end up with crackly audio and background noise, it’s a real pleasure to find something so crisp.

CRAFTsynth has line-out and headphones

It’s a DSP-based monophonic synthesizer with one voice, made of two oscillators you can adjust the balance of, and the usual selection of waveforms for each oscillator (Sine, Triangle, Saw, variable pulse on oscillator one, Since, Triangle, Saw, Square and Noise on oscillator two).

It has an unusual ‘Unison’ style mode that means it sounds more complex and ‘bigger’ than a typical dual DCO (digitally-controlled oscillator – but these are just DOs, maybe – they’re not controlling an analogue component) monosynth. The sawtooth wave is particularly fierce, and that’s not that unusual – even analogue oscillators often had one wave that had a higher output, or felt more ‘powerful’ than another, before mixing.

It can divide those two oscillators into eight detuned or fixed-intervals for phasing and chord effects. Output levels fall, so you do need to boost; at a pinch adding distortion brings the levels back up.

CRAFTsynth's editor/librarian runs on an iPhone, Android phone or desktop app - or tablets

The results of the spread control vary dramatically by waveforms, mix and modulation, and it’s definitely a case of ‘try it and see’ rather than an instant ‘set value, receive sound’ sort of affair, but they’re undeniably impressive.

It wouldn’t be a subtractive synth without a filter; it’s got an interestingly morphable one that defaults to low-pass, but swings through band-pass to high-pass when controlled with the Modal app, more on which later.

The filter’s character is… you’ve guessed it. Clean. Deftly slicing away the frequencies you don’t want with a fairly sharp curve and not much else going on, the resonance control appears to be acting more like a band-pass filter reducing the level of the unwanted frequency rather than exciting the desired ones.

Though there’s some indication that things get a bit lo-fi at times – plugin oscilloscopes show waveforms with lines like you tried to draw a circle with a mouse on an Amiga and got a hexagon instead – it never feels grungy.

Even the distortion is rather too well behaved, like that scene in Weird Science where Michael Berryman’s post-apocalyptic punk biker says “Can we keep this… between us? I’d hate to lose my teaching job…” on the way out.

Clean is good. It’s hard to clean up baked-in dirty, but you can always dirty-up baked in clean. Gain is important when mixing/recording the CRAFTsynth, the level control is for the headphones only and some patches can run out of oomph easily – or more precisely, until you get going on the ‘subtractive’ part of subtractive synthesis, it’ll push the meters into the red despite that lack of background noise.

You can always use an external filter if you want a different character; the stereo line output seems to function effectively a splitter, as there’s no control over panning. With a typical 3.5mm TRS to 1/4″ TS splitter, you can use one side for a dry mix and the other for effects.

CRAFTsynth plays well with other synths

The other aspect of that cleanliness is that everything is digtal. The filter’s digital. The LFO’s digital. The fingers you use to poke it are digital.

Limitations of CRAFTsynth 1.0

The amp envelope is digital, too, and it’s the only area that I’ve found an aspect of the synth I’m not thoroughly impressed with; it’s too quick to slice off the note you were playing and reset everything for the next one resulting in abrupt transitions.

Legato playing will change pitch within the envelopes, and you can glide between notes with very drawn-out slides but there’s not really much by way of control to allow sequences that have beat, but flow together.

It responds to velocity, too, but doesn’t appear to be able to route that.

The filter and amp envelope generators, both ADSR with inverse switch for the filter EG – so already well ahead of many low-cost synths – are tied to their destinations and the LFO can be sent to one of six.

You can’t, for example, assign the filter envelope to FM, even if you want to assign the LFO to the filter. But then it would only trigger once, there’s no retrigger.

On the other hand, this is the sort of complexity you don’t always find in synths costing five times as much; this is just telling you what it can and can’t do. For the price, it does FAR more than anyone would expect.

There’s only one genuinely frustrating restriction; although you can select scales, you can’t choose a root note. That five-key keyboard is more limiting than if you had some ability to chose which five notes you got in an octave freely, and of course, there’s no sequencer in here unlike some cheap lo-fi synths.

Even so, the Modal app provides a keyboard, as long as you have a Camera Connection Kit to hand for Apple gear anyway. The iPhone even provides enough power to run the CRAFTsynth.

You can use the iPhone as a virtual keyboard instead of relying on scales

Just to be clear, this is a synthesizer that costs £79. Hell, you can get it for £45 at the time of writing. I’m in no way criticising it for what it offers, it’s already blown any other hardware you could buy for the money clear out of the water.

The sounds it produces would be entirely acceptable if it were simply a featureless black plastic box plugged into USB and audio and wholly reliant on MIDI and the Modal app to shape sounds at all.

As it is, with eight knobs (well, you have to source your own, but the controls are there) and quick selection of menus, it’s even astonishingly easy to get creative and in-depth without resoting to the app…

Programming the CRAFTsynth

Despite the basic interface, there’s actually very little you can’t achieve directly on the CRAFTsynth itself – the only thing lacking is visual feedback of your selections when changing things like LFO shape or destination – at least until you’ve got some knobs or painted markers on the controls.

Envelopes skip through presets, rather than offering ADSR control from the front panel, and that’s about it for sound shaping limitations. A lot of features – preset selection, envelope shape – do need a good memory and the ability to read binary from the four-LED array, though.

However, help is at hand; the Modal app runs on iOS, Android and desktop machines, and it provides a quick link to the manual and a full editor, player and librarian with an additional 32 presets to play with. It has 32 banks available in total.

It’s possible to assign the mod wheel to different destinations, but even with the app there’s no way to change the root note of the five-note scale. Playing the on-screen notes includes velocity-based volume, getting quieter the further up the key you play.

Using the Modal app it’s also possible to polychain the CRAFTsynth, for a multitimbral polyphonic synth.

Are the presets any good?

Yes. There’s a genuinely interesting range of sounds for it, even in the factory 16-sound preset bank – the extra 32 you get via the app are equally diverse. They showcase the metallic quality of the sound nicely with some very neat patches for precussion, bass and building interval dance-type sounds.

As always, if it already exists, I see no reason to duplicate it, so enjoy the demos Modal made when the CRAFTsynth debuted in 2017.

Geeky stuff: What’s it running on, can it be hacked?

  • DSP runs on a 32-bit, 72Mhz ARM Cortex M4
  • Similar to the Teensy 3.2 + audio board with SGTL5000 codec
  • Connections are clearly labelled for hacks and mods

Anything can be hacked if you’re determined enough. Modal’s kit is, by design, not aimed at hackers – it’s like the Kinder Egg toy of kit synths and it’s all the better for it, as people who have no previous experience can assemble it frustration-free and feel like they got something good, for less outlay, and had some input on building and understanding how it’s assembled.

CRAFTsynth processor

Though the architecture is almost identical to a Teensy 3.2 processor board with audio shield, it’s an optimised PCB and crucially for those of you who equate DIY with saving money – it’s cheaper, not to mention a hell of a lot faster, than trying to get the bits together and run an open-source synth on the same platform.

The processor is a 72MHz MK20DX256 VLH7 – or ARM Cortex M4, which extends the embedded processor with native DSP instructions. If you care about such things, it’s faster and more powerful than the CPU tucked into a Pocket Operator, for example.

Audio is handled by the SGTL5000 Codec, which does offer a few more features than are enabled. How the synthesizer’s sound is divided between these components is Modal’s secret… but potentially, the audio processor can provide some filtering and gain features rather than everything being in DSP.

Clear labels on the headers for easy hacking

Of more interest is the ability to hack extra controls.

It looks like the easiest changes would be to the audio connections – upgrading to 1/4-inch jacks on a PCB cut to fit wouldn’t be difficult, for example, and the capacitive buttons and pot panel are equally straightforward. The headers are well labelled for such projects.

Modal encourage you to fit different knobs or construct your own cases. A stiff cardboard case would be sufficient to prevent accidentally touching the pins for the interface boards, for example. There are a number of clean patch points present too, which could be mapped to the schematics and I/O of the processor…

So, how awesome is the CRAFTsynth (1.0) DIY kit

  • Excellent value for money in every regard
  • More than capable of contributing worthwhile sounds to your studio
  • An outstanding gift, gadet and synth

Things like the CRAFTsynth don’t make it to market very often; usually if it’s affordable and designed to appeal as a ‘gift-for-X’, X will find it too basic or lacking in anything that makes it valuable beyond being a present. Likewise, if such kits are going to do anything useful, they’re expensive, or technically challenging.

The CRAFTsynth is as easy to assemble as a Kinder toy

Unlike Pocket Operators, that don’t need assembly and are more about repeating lo-fi sounds than traditional synthesis, or the fleeting comedy of a recreated Stylophone – the CRAFTsynth makes great sounds, is fun to assemble, good to look at and very affordable (even at £79, but at the current sale prices it’s a steal). It understands MIDI and integrates with DAWs well, and it’s far more powerful than say, a Korg Monotron you might think of as a stocking-filler synth.

Modal CRAFTsynth ownership envelope

  • Attack – instant fun, easy to assemble, amazing sounds
  • Decay – does need gain on more complex patches, limited scales, shape makes it less portable than other low-cost synths
  • Sustain – app opens up programming, makes the synth more usable. Very impressive scope of sounds for cost
  • Release – not really worth reselling once built if you don’t like it, but more than capable of producing useful sounds for years

The electronic musician in your life will absolutely love it if you’re looking for an appropriate present, and if you’re considering buying one for yourself, you’ll still be using it long after the distaction value is gone.

In short, this is one ‘novelty synth gift’ that won’t be in the bin after the party’s over…

Don't throw this one away!