PWM Mantis

PWM’s sophomore outing is an intriguing combination of old and new.

I must say, I am a fan of how Paul Whittington’s still‑nascent company PWM seems thus far to be characterised by the decision to celebrate, collaborate and co‑create. Their output to date comprises two instruments that aim to push things forward while clearly endeavouring to preserve some classic design philosophies. In the case of PWM’s debut, the Malevolent, this involved collaborating with Bristol’s most excellent Future Sound Systems, and if I remember correctly the term ‘Korg MS‑20’ was thrown about liberally as a key inspiration. In the case of the sophomore Mantis, it’s the late, great Chris Huggett on the ticket, the man responsible for icons like the Wasp and the OSCar, with a number of very intriguing design features to boot.

A little history to help explain the Mantis: before Huggett’s tragic passing in 2020, he and Paul Whittington had worked together, namely designing numerous instruments for Novation such as the MiniNova, Bass Station II and Peak. The Mantis, which would be Huggett’s last synth project, incorporates the oscillator design of the Wasp and unites it with the filter design of the OSCar, doubling both into a fully duophonic instrument. It draws from the worlds of digital and analogue, as well as from the East and West Coast schools, to create something that’s at once a little bit classic, quite unique and phenomenally versatile. A good microcosm of this is its envelope design. These are based around a conventional East Coast design with attack, decay, sustain and release, but as well as adding an extra ‘sustain fall’ stage, they can be set to cycle, like a Buchla‑esque function generator. Envelope 1 is normalled to the main VCA, though both are assignable to up to six modulation destinations. More on that later.

Player Ready

In my review of the Malevolent back in 2022, I took umbrage with its mini keyboard. Side note: unless they are truly miniature, á la the OP‑1, I think mini keyboards are, generally speaking, a waste of time. More often than not they simply add expense and take up space, all while those who do need keys are likely to connect a bigger and more playable keyboard anyway. The Mantis, thankfully, has 37 lovely full‑size, semi‑weighted keys (that’s three octaves), and a pleasant‑feeling keybed. Velocity, aftertouch, it’s all here. Wonderful. Similar to the Malevolent, the Mantis’ side panels snap on and off magnetically; something I’m still waiting to see a good reason for but which I hope means we’ll see some nice accessories in due course. Considering the weight of the Mantis, these can detach at any moment when picking the thing up, which is a bit of a hazard. So be sure to lift from the bottom.

On the subject of those mysterious side panels, this is also as good a moment as any to point out that at the time of writing PWM have not published a full manual for the Mantis, nor have they still for the Malevolent. Much as I love the precocious appetite for moving onto new designs, I do — ahem — look forward to seeing both of those soon. These are powerful and intricate instruments after all, and aside from the user experience, Whittington and team deserve to show off their work right down to the last Shift function. As of now, I’d imagine there are many complaining about there being too much guesswork, and I can’t but sympathise. Suffice to say, it feels like this issue is somewhat endemic to the industry in 2024: with websites revisable at any time and firmware updates available instantly, far too many units seem to be hitting shelves before all ducks are in a row, to the point that it’s almost as if many of them are still in beta.

At the back of the Mantis we find a power switch, USB‑C port, MIDI in, out and thru sockets, and a selection of quarter‑inch jack sockets for pedals, audio output and headphones.

The Mantis’ hardware, however, is very much ready, with substantial build quality that I’ll say is becoming of its price. As I’ve mentioned, it is a weighty synth — around five kilos — with a matte‑black metal and plastic enclosure, firm rubberised buttons and sturdy knobs. These do wobble a little in use, I should point out, but not to a hugely concerning degree. They also behave rather like encoders, in that when turning a knob quickly there’s an ever‑so‑slight lag perceivable between its physical movement and that of its parameter. Joyfully, there’s no screen to speak of, and little more than one layer of panel functionality. Tick.

Considering how much is here, that’s quite an achievement. Alongside a robust pair of synth voices, with a sub‑oscillator to boot, there’s an onboard ring modulator, a noise generator with adjustable density, a host of expression and modulation options centred around two LFOs, and an arpeggiator with adjustable bpm and tap tempo, clock division, swing, direction and octave range. The filter section boasts an impressive eight filter modes along with adjustable pre‑filter drive, and to cap it all off there are two digital bus effects on offer: reverb and mode‑adjustable chorus, which can be saved as part of a preset. On the subject of presets, the Mantis has a capacious 200 slots, and these are all instantly accessible, menu‑free, via two elegant columns of buttons laid out as two banks of 10 groups, each storing 10 patches. Simply hit bank A or B (the former containing factory presets that can be protected or overwritten as desired), hit a ‘10’ button and then a number. Done. Saving is equally quick and intuitive, and there’s even a handy Undo function for retracing one’s steps if needed — including save steps if you accidentally overwrite something. A lot of thought has gone into the design of the Mantis, and it shows.

Singing Voices

The Mantis’ musical architecture begins with its two DCOs, both offering sine, triangle, sawtooth and square waves — which all sound quite excellent and leave little to be desired. There are also two other, more curious options. The first of these is symbolised on the panel as a trio of organ pipes, and really does sound like a church organ, spreading what sound like subtly squared‑off sine waves spread across an octave or two. This spread is psychoacoustically rather interesting; ascend a scale on the keyboard and it’ll feel like you’ve arrived where you started, not unlike a Shepard tone. Of course, add some modulation and filtering into the mix and not only are lush, Hammond‑esque sounds readily available, this sound can be squashed and twisted in numerous different ways to make it, well, not organ‑like at all. The second ‘extra wave’ option is labelled WT, and this takes the form of a fairly simple wavetable moving through seven or so different harmonically rich shapes. As of now, user wavetables can’t be imported to the Mantis, but I didn’t find myself missing this: the pre‑loaded wavetable posits itself more as a ‘bonus’ option that works beautifully with other aspects of the Mantis’ architecture, and can achieve great results very quickly indeed.

The Shape knob has been deployed to good effect for all of the above. Since the oscillators are digital, there are options for it to influence wave behaviour beyond the conventional pulse width for the square wave. For the wavetable, for instance, it moves through waveshapes. For sine and organ, Shape adds negative or positive harmonics into the picture (de facto drawbars in the case of the organ — something Paul Whittington has described as another nod to the OSCar), resulting in a pleasing range of ‘cheat’ FM sounds. It’s another example of how the Mantis really does optimise its real estate, as well as why DCO sceptics should think twice before discounting it in favour of analogue for analogue’s sake.

Oscillator 2 has all of the above, plus one particular additional feature that ends up considerably expanding the scope of the Mantis’ overall voice. Density and Density Rate knobs pertain to what is essentially a third oscillator, in that oscillator 2 is in fact two identical oscillators working together. Dialling up the Density alters both the mix and frequency of the third, ‘hidden’ oscillator, while Density Rate pertains to the maximum amount of detuning. It means that those detuned, super‑saw sounds can be achieved while still miraculously leaving oscillator 1 to take on other duties — or, if you wish, can be used with oscillator 2 to create truly massive super‑super‑saw sounds. Or super‑super‑any‑wave sounds, for that matter.

The Mantis measures 620 x 320 x 110mm and weighs 5.3kg.

Two Plus Two

As mentioned, the Mantis’ dual analogue filters offer a huge amount of flexibility. I was expecting them to sound good (they’re descended from one of the most famous filter designs around, after all) and I wasn’t disappointed. Musical and decently throaty at higher resonance settings, they offer low‑pass, band‑pass and high‑pass options, (generously available with 12dB or 24dB/octave slopes, depending on the selected mode), and once again two extra modes that make creative use of their configuration. Wide Band places the two filters in series and renders one high‑pass and one low‑pass. With the Width knob expanding or contracting the resulting bandwidth, it makes for one very flexible tone‑shaping tool. Wide Notch, on the other hand, places the two in parallel and swaps them around to create a notch filter, which is once again adjustable with the Width control.

This is the point at which the Mantis’ voice structure gets slightly convoluted. At its most basic level it is indeed a fully‑fledged duophonic synth, with two discrete voice paths with their own VCAs and VCFs, each running their respective pair of oscillators (or, if we’re splitting hairs, four oscillators including the sub and DCO 2’s Density setting). While it’s not possible to stack everything into one super‑unison voice, it is possible to further spread things across four voices in a Quad mode. Since the Mantis only has two filters, it essentially takes on a ‘dual‑paraphonic’ structure when you play with four fingers, with the filters applied only to the first two notes played. But it’s not really paraphonic, strictly speaking: it would be if the two oscillators per voice were separated and split, but they’re not: in fact they’re replicated, just as they would be in a four‑voice polyphonic synth, with each note given its own VCA envelope. So in practice, that’s two filters but four VCA paths, so the Mantis can feel like a proper four‑voice polysynth... so long as you don’t require the filter envelopes too much. If you want to get the most from its filters, you’re better off sticking to monophonic or duophonic modes.

“Why not just give it four filters and make it four‑voice, then?” I hear you ask. It’s a good question, and one I’m not sure of the answer to. What I can tell you is that the Mantis’ design did not set out to be polyphonic, so once again this is essentially a very handy bonus feature, though one that shouldn’t be relied upon for the backbone of its sound. I don’t mind this. In my opinion a little limitation is healthy, even if it does feel like polyphony is being dangled tantalisingly close. Unlike many polysynths out there, it seems to me the Mantis is inviting — requiring, even — its users to think carefully about how they’re designing their sounds, how they’re optimising its available features and what they’re choosing to prioritise. For that I can’t in good conscience disparage it.

Extra, Extra

Beyond its fundamentals, the Mantis has a number of extra tools and little bonus features that significantly augment its design. Its modulation matrix is very well thought out, with three simple sets of six buttons for Control (that is, destination), Source and Scale. These can be used to compound a control source, like aftertouch or an external expression pedal, with a modulation source such as an LFO. It’s visual, quick and creative; while six modulation destinations sounds slim, in practice it feels like plenty since there are numerous alternative means of generating movement and character beyond these ‘usual’ means of modulation routing.

There’s an Osc Drift knob, for instance, which imparts some pleasantly tape‑flutter‑like instability into the DCOs. The LFOs each have a bipolar Fade knob for having the wave grow or decay with each note, essentially replacing the need to route an envelope to them. The envelopes have adjustable velocity response and, as mentioned, add an extra stage onto the conventional ADSR stages: sustain fall, which shapes the movement of a sound while the gate remains high, and can be set to cycle. As on the Malevolent, there’s a very useful Hold function for latching a drone, engaged by simply flicking the joystick down. The onboard effects are well chosen, with four different algorithms of lush, wide‑sounding chorus choose from (in addition to the stereo Voice Spread knob) and reverb. The Mantis’ Schroeder‑type reverb is nice and flexible, with its own filtering and time control, though frustratingly it’s in mono, so in many ways dialling it up results in the Mantis’ output getting narrower and smaller, not bigger and wider.

A synth with buckets of character, it requires a particular approach and certainly rewards the time invested.

Conclusion

If you’re looking for a polyphonic all‑rounder for two‑handed keys playing — even in a four‑voice capacity — I daresay the Mantis isn’t for you. If, however, you’re hunting down an extraordinarily versatile sound‑design‑ready synth, with chordal capabilities if needed, I recommend it very highly. Much like the Malevolent, the Mantis is not an instrument that will simply slot into your setup as part of the furniture, and nor is it trying to be — quite the opposite, in fact. A synth with buckets of character, it requires a particular approach and certainly rewards the time invested.

Information

£1289 including VAT.

www.sourcedistribution.co.uk

www.1pwm.com

$1349

www.1pwm.com

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