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Page 3: Arturia PolyBrute

Polyphonic Synthesizer By Gordon Reid
Published October 2020

In Use

Arturia PolyBruteThe PolyBrute's panel is nicely laid out and clear, with three knob modes — hook, jump and scaled — plus a 'panel mode' that will load the existing panel settings into the edit buffer so that (notwithstanding all manner of sound shaping parameters buried in the menus) what you see is what you get. There's also a shortcut to initialise the patch, which is always welcome. In contrast, programming the parameters accessed using its menus is unusual. It all hinges on the Settings button, which is the entry point to almost everything. If you press this in isolation, it takes you to a page with four per-patch menus and four Global menus accessed using the soft buttons below the screen. If you then select, for example, the first of these, you're taken to a sub-page with another four headings. Select the first of these and you find yourself on a sub-sub-page with six further headings. Press the first of these and you go down yet another level and are presented with eight further options. In this example, this is the bottom level and selecting any of these options determines your selection for the Voice/VCO/VCO1 Tune Modulation parameter.

Thankfully, there are shortcuts and you can jump to the screen just described by holding the Settings button and turning the VCO1 Tune knob. Indeed, you can access much of the system by holding the Settings button and turning or pressing something, but that doesn't hide the fact that the PolyBrute would have benefitted from a larger screen and fewer tiers. It also means that parameters accessed via the menus tend to offer options rather than allowing you to scroll through their ranges. For example, there are just eight swing values so, if you want a tad more or a tad less swing, you can't have it.

Having created your patch, you can name it and enter the name of its designer using the laborious 'select and scroll through the characters' scheme, allocate a single category to it, save it to one of the 768 onboard memories, and recall it in the usual fashion. But the PolyBrute also offers a Quick Save feature to overwrite the current patch, and a Snapshot system that allows you to store up to five snapshots of a patch as you edit it. If you then travel up a blind alley, you can select a previous snapshot of the patch before continuing to edit. You can also preview different patch locations before saving a new patch, which will help you to avoid overwriting something important.

I've had the privilege of playing and reviewing many of the most revered polysynths of all time, and I think that the PolyBrute has the potential to be up there with the best of them.

Turning now to the MIDI specification, you can choose individual channels for the Upper and Lower zones, and determine whether the PolyBrute sends and receives MIDI over DIN, USB or both. There are also parameters for local on/off, bank/program change on/off, and whether the arpeggiator and sequencer output over MIDI. Furthermore, most of the control panel is mapped to MIDI, although the system isn't all-encompassing because Arturia have limited it to the usual controllers and MIDI CCs. Far from disapproving, I welcome this because it makes it simple to create and edit automation. Unfortunately, Arturia (like so many others) haven't stuck to the MIDI Specification, with incorrect assignments of important controllers such as CC2 (breath controller) assigned to the reverb level, CC7 (volume) assigned to the Steiner filter level, CC65 (portamento on/off) assigned to VCO1 Sync, CC66 (sostenuto on/off) assigned to VCO1 Tune, and more. I don't know why manufacturers do this, and I really wish that they would stop. A much more complex system of 2500 NRPNs and RPNs is used for the editor which, when used as a plug‑in, turns the synth into a 'hard' soft synth with a wider set of automation and control features. In addition, the PolyBrute receives and sends analogue clock, so you can use it with suitable drum machines, modular synths and vintage instruments. This means that there are four clock sources in all, with an auto mode that selects any that is detected with a priority order of USB > 5-pin MIDI > Clock > Internal. Four analogue clock modes are provided. One Step advances the sequencer and arpeggiator each time that a clock pulse is received, while 2PPQN, 24PPQN (DIN Sync) and 48PPQN are pretty much self-explanatory.

But what's it like to use? In short, it feels really good, and its expression capabilities are remarkable. Despite being loaded with pre-production firmware, the review unit performed almost faultlessly throughout, with just some minor quirks with the Morphée that are too complex to describe here, plus some oddities with the snapshot function. No doubt there will also be some teething problems to be discovered once it's out in the field, but those will be for another day. My only reservation — other than having to remap MIDI CCs in existing sequences — was having the wheels positioned behind the Morphée because I almost always brushed the pad and caused unwanted things to happen when I reached over to use them. Consequently, I tended to program patches that used either the wheels or the Morphée, but not both. Despite the additional width required, I would have positioned the wheels to the left of the Morphée.

Inevitably, I had to run the oscillator and filter calibration routines once or twice per session to obtain accurate tuning and consistency across all voices, and this will almost certainly be necessary during the course of an evening on a sweaty stage. Should you ever need to recalibrate the performance controls, that's also possible and, if you get yourself into a pickle, you can reset all of the Global parameters to factory settings without affecting your patches. That's a nice touch.

Measuring 972 x 378 x 110 mm and weighing in at a hefty 20kg, the PolyBrute demands attention, and possibly a truss.Measuring 972 x 378 x 110 mm and weighing in at a hefty 20kg, the PolyBrute demands attention, and possibly a truss.

So now we reach the part where I have to try to tell you how it sounds. Well... it's aggressive. But it can also be smooth. It's sparkly. But it can also be dark and moody. It's warm. But it can also be glassy. It can dominate the mix. But it can also sit back. It's cultured. But it's also a thug. In short, it's a chameleon, and there's no way that I could plumb its depths in the limited time available. What's more, there's even more here than Arturia admit. Let me illustrate... I turned the Morph knob to A and programmed a simple single-oscillator sound with the oscillator's output directed to the Steiner filter alone. I then turned the Morph to B and created a second sound with the oscillator's output passing through the Ladder filter alone. I was then able to morph between these, with the outputs from the oscillators sent proportionally to the two filters when the Morph lay between its zero and 100 percent positions, rather than the Off or On available from the panel. The importance of this discovery became even greater when I discovered five utilities that (among other things) allowed me to save these intermediate sounds to either A or B. In other words, your patches are not limited to the filter routing available from the panel!

If you prefer not to plan your sounds quite so meticulously, the random patch generator is a boon. This creates new patches by selecting sounds A and B from elsewhere, morphing them by a random amount, moving the result to sound A in the edit buffer, selecting another sound B, morphing again, and repeating the process a random number of times. Because the bases of the generated sounds are (in theory) sensible, the results tend to be sensible too, far removed from the silly blips (or more likely silence) that you can obtain using random patch generators elsewhere. When you stumble across something you like, you can tweak it further and save it in the usual fashion. I used Generate to obtain patches ranging from gentle pads to experimental electronic effects that would have graced any episode of Space Patrol in 1962, and very nice they were too.

Of course, the PolyBrute would be even more impressive if you could play it with greater polyphony, and I suspect that some prospective buyers may think twice about buying a modern polysynth offering just six voices. But the likes of the Roland Juno 60, the Memorymoog and current instruments including the Sequential Prophet 6 and OB6 have proved that six voices need not limit the desirability of an analogue polysynth. Nonetheless, I still wondered why Arturia's engineers had limited it to just six, so I asked. They explained, "This came down to a combination of the physical size of the unit and pricing. We chose not to build a machine that would be beyond the reach of most, and as a result we had to choose what seemed essential and what could be more limited. Six voices seemed to be what most people would be comfortable with, and we focused on three primary axes of development: an analogue voice that sounds pleasant with most settings, expression, and morphing, which was a priority from the very start. We preferred to design the PolyBrute with six big voices rather than a greater number of small ones." In other words, we could have had an 8, 12 or maybe even a 16-voice version of the PolyBrute, but it would have been huge, heavy and unaffordable, and it might have been necessary to discard all manner of facilities to make it practical. What's more — and this isn't something mentioned by Arturia, but my own observation — I suspect that it would also have required fans, and the PolyBrute is mercifully devoid of these. Yay!

I have just two final observations before I finish. As on other analogue polysynths with bi-timbral or multitimbral voice allocations, it's possible to make the PolyBrute's VCAs pop, which can be disconcerting on sounds with slow attacks, but I found instances of this to be few and far between. Similarly, and in common with other large analogue polysynths, the PolyBrute hisses very quietly to itself, but I must admit to being impressed by the low level and unobtrusive nature of this. You might think that these observations are criticisms but, on the contrary, I think that great credit is due to the engineers for developing a pre-production unit with so few audio artefacts.


The conclusions to reviews can sometimes be quite long-winded, but I think that — despite having less time than usual to investigate and review the PolyBrute — it's surprisingly simple to sum up everything that I've learned about it.

In short, I've had the privilege of playing and reviewing many of the most revered polysynths of all time, and I think that the PolyBrute has the potential to be up there with the best of them. You're going to have to invest time and effort to get the best from it, but it's remarkably flexible, it's immense fun and it sounds superb. If there's anyone out there who still thinks of Arturia as a quirky little manufacturer of soft synths and low-cost hardware, it's time to stop doing so.


PolyBrute's rear panel connections close-up.PolyBrute's rear panel connections.

The PolyBrute offers a single pair of quarter-inch unbalanced stereo outputs to the far left of its rear panel. Then, toward the centre, you'll find 3.5mm sockets for analogue clock In and Out. These are followed by quarter-inch pedal inputs for sustain and for two expression pedals that you can direct to the filters' Master Cutoff and the volume of the patch, as well as to imitate the actions of the ribbon, the mod wheel and the X, Y and Z axes of the Morphée. The output from EXP2 can also be injected into the matrix.

A physical memory protection switch (that takes me back!) separates these from 5-pin MIDI In/Out/Thru plus a USB Type B socket for connecting the synth to DAWs and its dedicated editor. Finally, there's an IEC input for its internal universal PSU. A quarter-inch headphone output can be found at the front of the instrument, and this has its own level control so that you can set things up on stage without subjecting your audience to any unwanted twiddlings.

The PolyBrute Editor

Register your PolyBrute and you can download this editor for free.Register your PolyBrute and you can download this editor for free.

The PolyBrute editor is a free download for all registered PolyBrute owners and simplifies many aspects of programming and using the synth. Communication is bidirectional, so if you turn a knob or switch a switch on the hardware, the editor reflects this change, and vice versa. It's supplied as a plug‑in as well as a standalone package and, when used within a DAW, allows the host to control and automate the PolyBrute whether the changes have been created within the editor or on the synth itself.

The patch management and librarian facilities are common with many of Arturia's products, so you should have no problems naming, categorising, saving, searching and recalling patches. You can also organise patches into Projects, which is useful for live and session work as well as for album projects.

Although the version supplied during the review was at best an Alpha, it was remarkably stable and, after an initial problem talking to my 2017 MacBook Pro through a USB‑C to USB‑A adaptor, it ran faultlessly. As you can see, it's nicely laid out and it reveals many parameters that, on the hardware, are hidden in menus, which is very welcome. In addition, I particularly liked how rotating the Morph knob from A to B (whether done within the editor or on the synth itself) caused the values of all the relevant controls to move from one sound, through their intermediate positions, to the other. This made it much easier to visualise and program useful patches.

The Manual

The PolyBrute's draft manual includes a couple of mistakes that need to be addressed, but I suspect that all will be well by the time that you read it. More worryingly, it lacks detail. This became particularly apparent when I discovered that I could use morphing to design patches that send proportions of each oscillator's output to each filter, a superb capability that isn't even mentioned. When I queried this, Arturia's people suggested that explaining how specific parameters morph would significantly extend the manual so they decided (and I quote) "to retain a bit of mystery".

So which would you prefer? A 112-page manual that leaves much to be discovered, or a much thicker one that explains everything? I would choose the latter, but most people don't read manuals (their loss: I have no sympathy for anyone who buys a £$2000 synthesizer and gets £$200 of use from it) and handing over something as weighty as War & Peace is not going to encourage them to do so. Maybe this is one of those instances when an accessible User Manual should be complemented by an in-depth Reference Manual. Hmm... there's no maybe. It is.


  • It's deep. Really, really deep...
  • ...but it's also simple to use and great fun.
  • It's remarkably flexible.
  • The amount of performance control is exceptional.
  • It can — and usually does — sound superb.


  • Six voices will be too few for some players.
  • It would benefit from a larger screen and less menu-diving.
  • Some parameters that would normally have continuous ranges offer just a handful of options.
  • The MIDI CC map is non-standard.
  • The manual would benefit from more detail.


Despite a few niggles, the PolyBrute is a serious instrument that deserves serious consideration. I'm impressed.