Modal SKULPT review – your first VA synth?

Modal Electronics sub-£300, four-voice polyphonic desktop synth weighs just 427g. Let’s find out of the sounds are more substantial…

Modal SKULPT – £239-£269 – find offers on Amazon UK

  • Four-voice, 32-oscillator virtual analogue synthesizer
  • Portable and lightweight, with built-in sequencer and MPE support
  • Quirky design hides serious flexibility and potential

It’s a proven strategy for getting new musicians hooked on synths – make a neat little affordable monosynth, get players addicted to the creative potential and sound, then stack more of the voices together to make a polyphonic monster.

Modal Electronics is an established, vibrant British synthesizer company known for high-end analogue/hybrid models, but to reach a wider audience it introduced the super-cheap, super-fun CRAFTsynth.

Modal Skulpt synthesizer
The Skulpt is about 25cm wide and 13.5cm deep – it’s a lot smaller than it looks in pictures!

Having produced a little DIY kit that gained huge attention for the sounds it makes, it would be crazy not to stack a few of them in a bigger box and sell that to professional musicians… SKULPT does that, albeit with far more flexibility, in the form of a four-voice polyphonic, 32-oscillator beast.

If that weren’t enough, Skulpt Firmware 2.0 introduced MPE – MIDI Polyphonic Expression – as well as a few tweaks that help it fit into established MIDI studios with greater ease. It’s a free update and comes with updated Modal app and plugin versions to reflect the new capabilities.

Kickstarter backers agreed with the recipe, and it arrived in 2018, before flooding into shops in the middle of 2019. Every time I’ve seen one, though, it’s been behind glass – so what’s it like?

Encased in lightweight charcoal and grey plastic, the less-than-500g Skulpt doesn’t entirely feel like it’s aimed at studios, but it’s also a little overcomplex for younger musicians or simply diving in to to make sounds on the move. Skulpt doesn’t conform to any established format, which raises two questions. Who is it for, and does it sound as different as it looks?

Mobile sound creation and composition appears to be one of the key pillars of the design. There’s a touchpad keyboard, a hard shell to protect the controls, and it runs on six AA batteries or USB power; short of a speaker, it’s entirely self-contained for playing and creating sounds, sequencing and composing.

At the time of publishing, the Skulpt is as little as £214 from Juno or GAK, making it an absolute bargain.

Skulpt: first impressions

Once it’s in your hands you can be forgiven for thinking this isn’t a serious instrument. Rather than the predictable, if savvy approach taken by marketeers of analogue-era classics – and their virtual-analogue descendants – Modal forgot the metal chassis, the wooden end cheeks and, er, the keyboard. Sort of.

One design touch is really clear in both Skulpt, and Craft 2 – the ‘arrow’ of controls for ADSR and filter. Sustain is arguably the envelope control you’re most likely to want to adjust when playing, and it’s the easiest to reach from the keyboard. Filter’s the centre of it all, and resonance is right next to it to the right – ideal for wrapping an elastic band around for combined tweaks.

The Modal Skulpt front panel
The complete front panel of Skulpt is smaller than a typical 9.7″ iPad

Tbere’s a 16 zone, touch-sensitive glossy area that serves as a keyboard, providing patch recall, programming feedback and sequencer controls as well. The consumer-friendly bias is reinforced by the 3.5mm audio jacks and standard AA-battery power behind a big plastic clip-on cover.

Modal Skulpt ports
Full-size MIDI in/out, sync in/out, dual-mono line out, headphones and micro-USB power/MIDI

The slightly less ‘professional’ feel of the plastics and controls is offset by the liberal scattering of knobs and buttons across the front panel. There are full-size MIDI ports as well, emphasising the Skulpt’s place in an established setup. Modal are big on these – the CRAFTsynth 2.0 might be the smallest mass-produced synth with both MIDI in and out on proper DIN sockets.

Skulpt's lid doubles as a base
With the case underneath, the Skulpt’s flat and boxy shape is a bit odd – but very compact

Finding controls in the busy layout isn’t always easy; though everything is clearly marked, the fonts are a bit small and hard to read in low light, and most buttons and knobs perform more than one function.

I’ll cut Modal some slack for my less-than-perfect eyesight and the small text, but the pale-grey on mid-grey on dark-grey labels on the keyboard can’t be helpful to anyone…

There’s a handy cheat-sheet that fits in the plastic cover, which helps, but like the CRAFTsynth, the Modal app is just a smartphone away…

Modal Skulpt cheat-sheet
You’ll need thats shortcut sheet, at least for the first few hours of programming

That’s just the start – there’s a LOT more crammed into this little box than you’ll find in similarly-priced desktop analogue synths; at £229 to £269 depending on retailer, it undercuts many ‘cheap’ synths, but does have a few strong rivals; few offer this polyphony and flexibility though.

Game over? Not quite. You could be looking at some recreated analogue tech from Behringer in the same budget, or pushing finances a bit more for Roland’s four-voice Boutique synths; there’s also the MicroFreak. The Skulpt is definitely unusual, but it’s not alone on the music shop’s shelves (or online catalogues).

It needs something special to stand out…

SKULPTing sounds – Modal-style

Perhaps the most attention-grabbing aspect of Skulpt’s design is the right-angle, oddly-delineated user interface; secondary controls are signposted in Skulpt’s signature orange and accessed with a latching shift function. I think it’s badly-signposted in places and falls short of ‘accessibility 101’ for visual impairment, but ignoring that aspect of it – does it work?

You can dive straight in to shaping the two oscillator groups, three envelope generators, filters and delay straight away. Assigning the mod matrix without resorting to the cheat sheet or app is less intuitive, but remembering what the LEDs and shift functions relate to shouldn’t take long to learn.

Skukpt's orange on grey lettering looks cool but is quite small

Spend some time with it and the thinking behind the layout becomes clearer. The encoders are tall and thin, widely spaced so you don’t knock nearby controls, easy to adjust and very responsive. Only one of the knobs diverges from this design – cutoff, in proper synth tradition, is really obvious. Because they’re encoders, you always start from the loaded patch’s values; no sudden jumps in sound here.

Adjustments are fast and free of aliasing – you can play Skulpt like an analogue synth and it’s very hands-on, there’s no lag or digital artefact disruption to be found when enjoying the morphable waveforms or filter, for example.

The Modal Skulpt
Skulpt is dominated by tall, thin encoders that are easy to use without disturbing others

The buttons are flat, and have a positive click. The spacing of the controls, illogical at first, makes sense when you consider playing the synth hand-held or on the move; you’re unlikely to knock a control or get the wrong one when jolted in a train, or passing the synth between friends.

Values are shown as a row of LEDs on the keyboard, so though most things operate from 0-127 or +/- 63, you can at least get a vague idea of how far through the range you’ve gone. For all the digital, DSP-ness inside, the Skulpt tries to encourage hearing your sound-shaping, not calculating it based on values.

Given enough time, it becomes pretty intuitive – but it still feels a bit like the synth version of a hacker’s keyboard with black letters on black keys.

Modal Skulpt controls
Orange is high-contrast, but the lettering is quite small

Touch typists might be fine, but the style isn’t conducive to bringing novices in – which is a shame for something so powerful and yet, so accessible and affordable in other ways.

The most recent firmware update introduces one welcome feature to the keyboard. Preventing the accidental triggering if you touch the base, a global touch pad sensitivity setting adjusts how trigger-happy the keyboard is.

Ironically, the black Skulpt was a stretch goal in the Kickstarter, and backers of the original batch got white Skulpts with clearer (for my eyesight, anyway) labels on the keyboard. I suspect those original white Skulpts will become collector’s items in the future…

How does it sound?

Skulpt’s strength is in creating complex, evolving eerie textures that aren’t relying on samples or trickery; the long envelopes, comprehensive routing and modulation options and animation sequencer all work together to make this lightweight synth a veritable terraforming powerhouse for audio landscapes, yet one that won’t scare off amateurs from finding their own sound.

It’s capable of traditional synth punch too, but the filter’s character holds it back from quite getting the classic analogue ‘feel’ of a sound. Given the price and the number of synths that chase that almost half-century old tone, I don’t think that’s a bad thing, but it’s one of the few times Skulpt-ing feels more like design-ing.

Skulpt and Cozmo
Building sounds with Skulpt is not a robotic process

Underlining the difference between digital and analogue technology, the user sees two waveforms to blend between – yet the Skulpt’s DSP has eight oscillators per voice – and the four voices can be stacked, meaning up to 32 oscillators at once depending on mode.

If that sounds generous, it is. Modal’s latest release, the much-anticipated Argon8 synthesizer, also uses 32 oscillators, and shares them out for for eight-voice polyphony.

There’s a big difference, though – Skulpt offers just two simple waveforms per voice rather than already-complex wavetables. You can morph freely between them to create more complex waves, but it’s closer to being a polyphonic CRAFTSynth 1.0 with sophisticated modulation and routing, rather than a cut-down, portable Argon8 or four-voice Craft 2.

Skulpt: oscillators

The architecture presents the oscillators as a classic dual-DCO design, sweepable between sine, triangle, saw, square and variable pulse on the first oscillator and sine through square fading into noise, then low-pass filter on the second (the final couple of shapes aren’t noise, and can be used to introduce an analogue-like variance).

Both oscillator waveforms are available as destinations for modulation, as is the mix between them, so you start off with a very powerful yet pure, traditional way of creating a tone ideal for learning about subtractive synthesis.

You can’t set the pitch/range of each oscillator individually as you would on many traditional synths, though. The second oscillator has fixed-interval detune relative to the first – up to +/- four octaves. It achieves the same goal, with +/- 100 cents fine-tune to er, fine-tune the difference between the two.

Making use of the full 8 oscillator structure for colour and tone, rather than volume, is easy thanks to Modal’s ‘spread’ control. This detunes the oscillators across 64 different combinations, with a further 9 pre-programmed musical intervals for preset chords.

Where most synths get louder when you enable more oscillators, the Skulpt’s already using 8 in unison per voice anyway – so enabling spread creates a richer set of harmonics, that cycle and shift, but reduces loudness.

In addition to the phasing, evolving ‘fatness’ of this mode (though, you need to turn up the gain as levels reduce accordingly), the spread control can also effectively provide a sub-oscillator for FM and ring-modulated shapes – though it’s the same waveform generated by the combined blend.

The Modal Skulpt polyphonic synthesizers

If all you want is a huge block of monophonic power, it’s even possible to stack all four voices – 32 oscillators – in Unison mode, with detune. Never mind a wall of sound – this is a veritable fortress.

While we’re on the subject of oscillators, let’s not overlook the two that have a different role in shaping sounds. Skulpt has two LFOs – LFO1 is a master LFO that affects all sound from trigger to end, LFO2 is polyphonic, affecting the notes as they’re played.

Both can be synchronised to clock (internal or external) or free-running, but where LFO1 stops at 1/64th steps, LFO2 operates at audio rate, up to 3x root note.

Skulpt: filter

Modal’s sound is, in part, defined by the morphable two-pole resonant filter. Like the CRAFTsynths’, it’s DSP – not an external analogue filter, and it sounds closer in behaviour to the original Craft kit, than the Craft 2. That’s not really a shock, as Craft 2 is a newer design, where Skulpt is a progression of Modal’s first affordable DSP synth.

Morphing from low, band and high pass can be modulated, creating some very unusual sounds, and though it’s not self-oscillating in the sense of going wild based on (non-existent) background circuit noise, it’s got a fairly aggressive ring to it as you emphasise the harmonics. However, like the spread control, all Skulpt’s magic comes with a price; to really hear the quality of the filter, you’ll be upping the gain you’d originally turned down on the pure-sine init patch.

It’s not what I’d call warm – but a lot of that is down to the ‘perfection’ of Skulpt’s virtual engine, and it’s a criticism levelled at virtual analogue synths since the days of the Nord Lead. It is, however, capable of dramatic sweeps or subtle control – aided by the comprehensive modulation matrix…

Skulpt: modulation

Class of 2020, if I have one tip for you today, it’s… not to wear sunscreen (we’ve barely been allowed outside), but instead, make a bank of patches for your Skulpt that have preset modulation arrangements to send the LFOs places. It’s the fiddliest part of using it without the app, and yet the standout feature of the Skulpt is how powerful, flexible and easy to understand the mod matrix is.

LFO and controller sources can be assigned to multiple destinations, and they can work in conjunction with three ADSR envelope generators. The filter and amp contours shape sound over an eight-second transition – up to four seconds of attack, two seconds of decay, and four seconds of release. The mod EG can be assigned to various destinations, and all three can be inverted with the ‘depth’ control.

This is a lot of words – long story short, if you’ve never moved beyond a basic filter and amp envelope when making your own sounds, Skulpt encourages more advanced sound shaping, making it very easy and rewarding.

Distortion and delay – Skulpt’s effects

Already comprehensive, the Skulpt’s set of tools has a final flourish in the form of a waveshaping distortion and a very effective delay. Joining up the delay and LFO is particularly pleasing, with everything from sharp gated pulses to shimmering textures just a few tweaks away.

The delay can be tempo-synched, up to a maximum of 750ms. Feedback up to 90% can be left to tail away, and dub-style effects can be modulated by setting delay time as a destination in the mod matrix (or using external MIDI control), it’s great fun and becomes part of the patch in a way few other synthesizers offer.

Distortion is a simple wet/dry mix control, and small amounts can helpfully lift the perceived volume of a patch without much disruption. Even on strong basses it can be quite subtle, and almost feels more like a modulated comb filter responding to resonance. It’s described as waveshaping, but there’s no indication of if the waveform used for the distortion is controllable, only the mix.

So, what does it all sound like? As mentioned before, I don’t really see much point in recreating the excellent work other people have done, so here’s a link to Modal’s demos of the Skulpt. You can keep reading, though, to get some patches I programmed while reviewing the synth.

Demos of the Modal Skulpt shared by Modal

Never out of step

One of the more powerful features of Skulpt is less obvious from the front panel, despite the keyboard and logos. The 256-note, MIDI-clock resolution sequencer records in real time, and shows progression from start to end on the 16 keyboard LEDs; if you’re recording an 8 bar, 64-step sequence it’s counting down to the end rather than counting through each bar, which is very welcome.

You can quantize if you want, or just record as-played which proves to be very effective and predictable, catching small intervals between notes as chords are formed and generally sounding very natural. Chords can be sequenced too, and overall, it’s a very intuitive process to record a quick loop (overdub is automatic for building in stages).

There are four parameter automation lanes, which follow the chosen length of the sequence – yes, you can build a modulation sequence over 8 bars. When using the Skulpt directly, you just move the selected parameter and it records the changes. You can mute animations or notes for more performance options, again, via the touch pad keyboard.

The Animation sequencer in Modal app/plugin
The ‘Gotham’ sequence of animation…

Dive into the app and the scope of the sequencer is revealed in full, and you can also manage a library of 8 banks – the Skulpt can hold four banks of 16 sequences each, which is pretty generous.

Although the Seqencer page of the app looks like it would present a matrix for note step entry or editing, that’s only offered for the four parameter-locked animation sequences. The lack of a visual step sequencer is a surprise here, given how very polished every other aspect of Modal’s software has been – but then, being able to edit the animation sequences may prove more useful.

You can’t, currently, chain sequences into songs, but MIDI CC#0 is assigned to ‘Seq Load’ from 0-63, suggesting it would be no problem to chain sequences externally and indeed, for Modal to find a way of implementing pattern-chaining at some point in the future.

I’d happily sacrifice another bank of sequencer patterns for 16 song chains, particularly if one of the four animation tracks could be used for patch changes in that song sequence.

Keeping it together: Patch storage

SKULPT’s 128 patch locations and 64 sequence locations are accessed – you’ve guessed it – via a shift key combination. Without a display to show you the names, it’s one of the times the app comes in really handy – quickly browsing and selecting patches on the computer or iPad/iPhone makes up for forgetting which number you’d popped “sweeping pulse pad” under

Of course, the handy plastic lid is ideal for printing and hiding a cheat-sheet in. Or on, if you don’t mind stickers.

Sound banks can be imported and exported in the plugin or app, and there’s a patch toolbox that allows you to copy, move and rearrange your patches. Speaking of patches…

Free Modal Skulpt patches

Here’s a bank of 16 sounds I created while reviewing the Skulpt. Many of them use aftertouch or mod effects, for example ‘VangError’ breaks up and glitches, but that can be faded out with pressure. Harpsuschord release time is controlled with the mod wheel, and spread with pressure.

These aren’t being released as a ‘look what I can do’, but more of a ‘this is a small window of Skulpt’s diversity and you’ll be able to improve on them’. But it does reveal one big thing – the Skulpt’s sound engine and environment is so welcoming, particularly with the app, that I felt I’d created at least four or five patches in this bank that I’d have been happy to find as presets.

Usually the more sophisticated the synth, my lack of programming experience vs. the provided patches or readily available banks becomes really obvious – this synth is sophisticated and easy to use.

Firmware 2.0: Major changes

  • MPE support – polyphonic modulation of parameters over MIDI
  • Sustain / Arp Latch Mode – chords and arpeggios can be held and changed
  • Global Tune
  • MIDI-in Octave global setting – adjusts the range the Skulpt is operating in relative to the MIDI notes, in the same way that you select the range of the keybiard.

Is the Modal Skulpt worth buying?

  • One of the most user-friendly virtual analogue synths ever
  • As long as you’re using the app or plugin
  • Few hardware rivals, but comes worryingly close to software

If you’re asking if Skulpt is good value, it is, undeniably.

The flexibility of the routing, the quality of the sounds and the cost for such a versatile sound engine is brilliant. It’s backed up by one of the nicest, most versatile software editors I’ve seen in a long time. Over the past few weeks I’ve discovered and created a lot of useful sounds very quickly.

Skulpt fits into a cramped studio space well and doesn't need robust stands
The small, light synth fits into any project studio’s space easily

It’s something of a theme with Modal’s synthesizers, it seems, and probably the biggest challenger for this spend is ‘two CRAFTsynth 2.0s’.

Quick, basic sounds are easy to shape on the front panel, and thanks to Modal’s app, more advanced programming is a wonderful experience too, very easy to get to grips with, making this an ideal starter synth for building more complex sounds.

Ownership envelope: Modal SKULPT

  • Attack – amazing preset sounds, impressive sequencing and polyphony for the price, looks cool
  • Decay – feels almost too light and insubstantial, can take time to understand gain staging to compensate for varying levels
  • Sustain – excellent programming interface via app, genuinely versatile sound engine, lots of potential silliness when used with external effects due to dual-mono output
  • Release – unless you build your career on it and bond with it, it lacks the robustness to feel like a synth-for-life; if you try an Argon8 you’ll probably sell it to upgrade

Skulpt, like CRAFTsynth, is pure DSP, there’s no analogue mojo in here to distinguish it from software (there’s an abundance of digital mojo, though – a concept that’s yet to really click with some synth players) – and that could be turned into an advantage.

Although plugins at this budget are insanely good, the Modal Skulpt is far more interactive than a plugin, it’s a dedicated, portable hardware device. When you get this level of hands-on control combined with this kind of sound, even if all the processing is handled on a host computer, you’ll often find that you’re paying more for a ‘dumb’ controller.

It still raises a dilemma for buyers, though. If your DSP-based synth really only becomes truly accessible with some software, its biggest rival is… software, and the Skulpt doesn’t have the feel of a device built to be carried around without care, The hard plastic top cover only protects the top, after all, and I’m not testing to see how well it survives drops.

In part, the Skulpt feels like some market research identified ‘weight and lack of portability’ as a barrier to hardware ownership and focused on solving that with absolute efficiency, but is the size and weight of the synth really that much of a factor?

I’d almost prefer if it the Skulpt had some of the heft and brick-like quality of a Novation Circuit. The keyboard in particular could be better – it tries to do too much, with too few pads; it could easily just be 16 buttons – or in the space provided, 32 – with clearer labels and more features directly accessible. In fact, Modal implemented this very approach in the CRAFTSynth 2.0 – it has widely-spaced pads for playing, and a row of narrow function pads above.

As with the right-angled labels, I can appreciate what Modal and Almond Design were aiming for (I’ve seen users refer to the touchpad as glass – think ‘iPad interface’). It’s interesting to see the evolution in the newer, smaller synth.

Modal Skulpt's 3.5mm jacks

What would really make Skulpt amazing would be to make the Modal app and VST a 100% preset-compatible softsynth version of the Skulpt.

That way you could shape sounds on the road with the hardware, take it anywhere for jamming and gigs, but save yourself some extra cables and the need for another input on your mixer when recording at home.

Could Skulpt be improved, then?

For what it costs? I seriously doubt it! There are two, maybe three accessories I would pay extra for though, and if you think that’s an unlikely scenario remember that Teenage Engineering charge half-as-much-again to put a small shell around a pocket operator…

  • A thick, impact resistant rubber base shell that wraps around the corners.
  • A rechargeable battery pack to clip in, with a micro-USB port for recharging (just use the same cable used to connect it)
  • A replacment textured/rubberised cutoff knob (already easily sourced)

Arguably Argon8 is the sensible direction for Skulpt 2.0. The desktop version costs less than two Skulpts, and for that you get twice the polyphony, wavetable-based oscillators with similar character to the Craft 2, but ‘moreso’.

It also features proper 1/4-inch audio jacks, built-in stereo effects, an audio input. and a clear, logically laid-out front panel including a modulation joystick and a display, yet isn’t that much larger than Skulpt in module form.

Modal Skulpt battery compartment
Battery compartment doubles as a stand, tilting the Skulpt nicely

Personally, I’d be just as happy with Skulpt as a portable instrument if the entire hardware interface had been devoted to choosing presets and controlling sequences, and all the sound editing were down to the app. If ever a battery powered smartphone-compatible synth needed MIDI over bluetooth, though, this is it.