Arturia PolyBrute 12

Arturia’s PolyBrute has gained six voices and a lot more besides.

Very occasionally, a manufacturer decides to throw everything it knows into the creation of a flagship synthesizer. Eschewing simplicity and intuitivity (did I just invent a word?), the designers’ task is to make everything possible, even if this means that the musician will have to think about how to program and play the resulting instrument. Sometimes, the additional complexity means that almost no‑one will ever plumb its depths, and many of its advanced features will never be appreciated by the masses unless, perhaps, one of its more interesting sounds is plastered over the latest TikTok sensation. On other — perhaps rarer — occasions, the hardware and software design is clever enough to reveal the underlying power while avoiding the worst excesses of arcana, allowing the likes of you and me to understand what’s going on and to discover new sounds and performance possibilities for ourselves. All of which brings us to the PolyBrute 12.

Under Pressure

Much of the PolyBrute 12 is the same as its predecessor, the PolyBrute, which I reviewed in SOS October 2020. Four years ago, I found this to be a superb synthesizer and, in my view, it has long been overlooked and underrated, perhaps for no reason other than because players don’t expect a polysynth of these capabilities from what many view as a manufacturer of soft synths and low‑cost monosynths. So how does the PolyBrute 12 exceed the capabilities of its predecessor? Surprisingly, there are just two significant differences. But they’re goodies.

Let’s start with the most obvious; the PolyBrute 12 has twice the number of voices as its predecessor, and hence twice the maximum polyphony. Nearly 50 years ago, the Prophet 5 showed that you can create a superb synthesizer with as few as five voices, and there are some excellent modern instruments such as the Prophet 6 and Oberheim OB‑6 that still do very well with just six. Nonetheless, increasing the number of voices extends what you can do with a polysynth, so we shouldn’t underestimate the importance of this. Whereas you have to be quite careful to avoid note stealing on the six‑voice PolyBrute, you can play more naturally on the 12‑voice PolyBrute 12. I experienced the same improvement in 1987 when I replaced the six voices of my Roland JX‑8P with the 12 of a Super JX‑10, the latter of which remained my big analogue polysynth of choice for more than a decade. Mind you, the JX‑10’s appeal wasn’t just that it had more voices; its velocity and aftertouch‑sensitive keyboard was exceptionally playable, making it the most expressive analogue polysynth of its era. All of which brings us to the second upgrade that defines the PolyBrute 12.

Despite its importance, you won’t see much evidence of this on the synth itself. The only visible difference is a small, extra pane in the column of voice management and control selectors to the far left of the control panel. This includes a single button annotated Aftertouch, which selects between three options. The first of these is Mono (more correctly called Channel) aftertouch, which is by far the most common implementation, and the only form offered on the original PolyBrute. When you lean on any key after it reaches the bottom of its travel in this mode, every note being played at that moment is affected equally, whether to add growl or vibrato, or affect the loudness or brightness... or whatever else you have programmed aftertouch to do. The second is Polyphonic aftertouch (or Poly‑AT), and this allows you to control individual notes when you press down on them, making it possible (for example) to swell or add growl to a single note in a chord, or to add vibrato to the upper notes while keeping the lower ones steady, and much more. Finally, there are the Alt modes that you select using a combination of the third Aftertouch option and the screen/menu system. As far as I’m aware, these modes are unique to the PolyBrute 12, so they appear to represent a very rare thing: a genuine development in the field of keyboard performance.

The Alt modes have been made possible by the development of a new keybed that knows the position of each key in its travel. Arturia have then made use of this in three ways to provide different ways of articulating individual notes while playing. The first of these is called FullTouch AT. With this selected, a note is triggered as soon as you start to depress a key (ie. at the very top of its travel) and, while the velocity is still measured correctly, the rest of the key’s vertical travel determines the polyphonic aftertouch value, from zero at the top to maximum when the key is fully depressed. So, like traditional Poly‑AT, you have three values generated when you press a key: the note number, its velocity and its aftertouch, albeit with a new method employed for generating the values for the last of these.

The second Alt mode is called FullTouch AT > Z, and this adds a further dimension of expression. Again, the note is triggered at the top of the key’s travel and velocity is correctly handled. And, again, the aftertouch value is determined by the position of the key in its vertical travel. But now the traditional aftertouch sensor at the bottom of each key’s travel is employed to generate the ‘Z’ modulator that you more usually obtain by moving the Morphée pad down and up. (No, I don’t mean ‘up and down’ — think about it!)

The third mode is FullTouch Env > AT, and this is the one that’s going to cause confusion, not least because the manual doesn’t describe it fully. (A lack of detail was a fault with the original PolyBrute manual, too.) Having spent hours trying to work out what was happening, I admitted defeat and contacted Arturia. It turns out that, when designing sounds to take advantage of FullTouch AT and FullTouch AT > Z, the developers found that they were leaving the filter and amplifier open so that they could use FullTouch to control other aspects of note development, timbre and modulation. So they designed a mode in which the VCF and VCA envelopes no longer act as ADSR contour generators, but are replaced by modulation values that are determined by the key velocity and vertical position. Having decided upon the basis of the system, they then decided to make each of those values the sum of two new signals. The first of these is called Pluck, and this is a simple AD transient. Its fastest attack rate is quoted as below 4ms, but it can be lengthened a little by increasing the value of the attack fader of the appropriate envelope generator. The decay rate is then controlled by the decay fader, and the maximum amplitude of the transient is controlled by the velocity fader, although there’s a lower velocity threshold that helps to ensure that you don’t generate a Pluck by accident. The second signal is called Touch, which is a contour determined by the position of the key at any given moment. However, the ADSR faders in each of the VCF and VCA envelope panes also affect this. The attack and decay faders determine the slew rate when the key moves down or up, respectively. The Sustain value is more complex. When positioned below 50 percent, the generated values are lower than they would otherwise be, lowering the relative amplitude of the Touch and emphasising the Pluck to create, well, plucked sounds. But when the Sustain is positioned above 50 percent, the Touch signal remains high. This was implemented so that the VCA can be kept open even while a key is being moved up and down to control the filter. The release fader then controls the release time as you would expect. Finally, the aftertouch sensor at the bottom of the key’s travel is again active, so you can still lean into a note and generate Poly‑AT in addition to all of the above.

The PolyBrute 12 measures 972 x 435 x 156mm and weighs in at a considerable 23kg.

In many reviews in the past, I have written that it’s harder to describe something than it is to use it, but that’s not the case here. The three FullTouch modes are, as far as I’m aware, unique to the PolyBrute 12, and learning to play them proficiently is going to take time; trying to hold a given note at a specific height while moving others up or down is, at best, bloody difficult. I haven’t mastered this yet and I’m sure that it will take me considerable time to do so. But if you decide to put in the effort to become a Zen master of FullTouch, I suspect that the results could be very special.

I should also mention that, in addition to all of the above, the PolyBrute 12 supports MPE. When sending, all of the aftertouch modes send channel pressure on a per‑note basis, with the FullTouch Env > Z and FullTouch Env > AT modes sending MIDI CC74 as the secondary parameter when a key is pushed into the aftertouch sensor at the bottom of its travel. When receiving, channel aftertouch, poly aftertouch, FullTouch AT and FullTouch AT > Z are each routed to aftertouch and MIDI CC74 on a per‑note basis, while FullTouch Env > AT is routed to the VCF envelope and aftertouch respectively. There are further complicating factors to do with polyphony and how voices are allocated when you use both of the PolyBrute 12’s voice Zones, but I suspect that you’ll have to read the relevant section of the manual at least twice (if not more) to understand these. I tested the MPE facilities using a Roli Seaboard 2 to see how the PolyBrute 12 responded when receiving MPE, and Arturia’s CS‑80 V soft synth to check the MPE generated by the PolyBrute 12. After a bit of jiggery‑pokery to set everything up and to work out what was happening in any given mode, everything seemed to work as it should.

It’s A Kind Of Magic

Do you know what happens when you double the number of voices in a digital synth? You get to play twice as many notes simultaneously, that’s what. But do you know what happens when you double the number of voices in an analogue or hybrid synth? It gets heavier. A lot heavier. Now, every synth I’ve ever owned has become heavier as the years passed, but the PolyBrute 12 isn’t a vintage synth, so you may feel that it has no business being as heavy as one, even though it’s obvious that this is a consequence of the extra boards necessary to generate the additional voices. But this leads to another potential problem. As Sequential discovered way back in 1978, if you stick 10 voices in a case suitable for five, the synth gets hot. And then it gets unstable. And then it gets unreliable. And then it stops. So, for the PolyBrute 12, Arturia have increased the size of the PolyBrute’s case, making it higher and adding a substantial extension to the rear. This extension has vents at the top and bottom that allow warm air from inside to escape upward, at the same time sucking in cooler air from underneath. Since these vents run the entire length of the case, there’s no need for a cooling fan, to which I say ‘yippee!’

But despite the extra size and weight, I’m not going to complain. Sure, the PolyBrute 12 isn’t as manageable as the latest lightweight polysynths from elsewhere, but there are two bonuses. The first is obvious: it feels solid when you play it. The second is that the keys on the newly designed keybed can be longer than those on a shallower instrument, which means the pivot point can be further back, which in turn means that the keys stay flatter as they move up and down. Depending upon your keyboard‑playing background, this may be of little consequence, but it will feel much nicer to anyone brought up on an acoustic piano.

But what of the sound? I suppose that the easiest answer to that is that it’s no different from that of the original PolyBrute, which is both true and misleading. Let me make an analogy. Imagine two otherwise identical guitars — one that allows you to bend each string individually, and one that always bends all six strings simultaneously, whichever you push against. Would you say that the two instruments sound the same? I doubt that you would. And so it is with the PolyBrute and PolyBrute 12.

I realised this as soon as I started to play it. Its first patch is called The Opening, and is an homage to the opening titles of Blade Runner. It uses the FullTouch Env > AT mode and allows you to control the level and filter cutoff frequencies of individual notes while holding the current chord, further extending the amount of control that Vangelis had when using the polyphonic aftertouch of the Yamaha CS‑80 to record the original. With a bit of tweaking — most obviously suppressing the Touch and extending the reverb by a considerable amount — the results could be magical, and the combination of the ribbon controller and the FullTouch Env > AT mode made it possible to do things that would otherwise be impossible. I was impressed.

The rest of the new sounds that take advantage of the FullTouch modes are scattered among the 400 or so existing PolyBrute patches, which is a shame because it takes time to find them. (I would have created a dedicated bank.) Some of them proved to be excellent, others less so, but they all illustrate how you can make sounds come alive with improved performance capabilities. Perhaps the only thing that’s missing is the ability to add vibrato using side‑to‑side movement. This is another natural way of affecting a sound, but the number of synths that offer it can be counted on the fingers of one hand. Maybe Arturia will consider it for the PolyBrute 24.

In addition, we mustn’t minimise the importance of the increased number of voices. The PolyBrute 12 offers all manner of assignment modes including polyphonic and dynamically assigned unison, and these become far more usable with 12 voices rather than six. You can also do more with the sequencer, which is now 12‑voice polyphonic.

So, everything is fantastic, right? Well... not entirely. Although the pluses greatly outweigh any minuses, Arturia have missed the opportunity to correct the PolyBrute’s MIDI specification in the new model. I understand that leaving it untouched maximises the compatibility between the PolyBrute and the PolyBrute 12, but having things such as MIDI CC2 (breath controller) affecting the reverb level, CC7 (volume) affecting the level of the Steiner filter, CC65 (portamento on/off) affecting VCO1 sync, and more... is just wrong, and means that you have to remap your MIDI CCs if you want to direct existing sequences to the PolyBrute 12 instead of another synth, or vice versa. This should have been corrected years ago.

Arturia could also have taken the opportunity to place the pitch‑bend and modulation wheels in their rightful places alongside the Morphée. After all, the PolyBrute 12 is both higher and deeper than the original, so why not make it a bit wider too? It’s far too easy to brush against the Morphée when using the wheels in their current positions and thus create accidental and unwanted effects, so this was the company’s opportunity to right another wrong.

Finally, I have to say that the (thankfully optional) wooden legs look wrong on such a powerful synthesizer. If I could have offered Arturia some advice before announcing these, it would have been ‘don’t’. Things that looked appropriate 60 years ago on a Selmer Pianotron or some long forgotten transistor organ do not do so in 2024. You may disagree.

We Will Rock You

Four years ago, Arturia’s engineers told me that they designed the original PolyBrute with six voices because it “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.” Consequently, I speculated that a 12‑voice version might have been too big, too heavy and too expensive. Happily, this hasn’t proved to be the case. It’s bigger, heavier and more expensive, but not ridiculously so.

Having spent some time with the PolyBrute 12, I find it to be lovely to play and closer to an acoustic instrument in terms of articulation and expression than any other polysynth I know.

The rest of the difference lies in the ways that you can articulate and add expression to those voices. With its polyphonic aftertouch, FullTouch modes and MPE, it’s a huge step up from the original, and capable of much that wasn’t previously possible. Some of the factory patches illustrate this well, but it’s not until you begin to delve into tweaking these or programming your own sounds that you fully start to appreciate the new capabilities. Having spent some time with the PolyBrute 12, I find it to be lovely to play and closer to an acoustic instrument in terms of articulation and expression than any other polysynth I know. Whether I’ll ever develop the skills to take advantage of this is another question but, for those who do, the PolyBrute 12 could well be their synthesizer of choice. If you’re still one of those who views Arturia as a manufacturer of soft synths and low‑cost monosynths, it really is time to stop.  

Information

£3429 including VAT.

www.sourcedistribution.co.uk

www.arturia.com

$3999

www.arturia.com

When you purchase via links on our site, SOS may earn an affiliate commission. More info...

When you purchase via links on our site, SOS may earn an affiliate commission. More info...