Most expressive keyboards ask you to press past the note-on point before anything interesting happens. Polyphonic aftertouch only kicks in once a key bottoms out, which means a huge portion of a key's physical travel is spent doing nothing more than triggering the note. Arturia's PolyBrute 12 takes a different approach with a keybed technology it calls FullTouch, and it's worth understanding both because it's a genuinely different design philosophy and because the synth ships with proper MPE support baked in.
Three Aftertouch Modes, Not One
The PolyBrute 12's 61-note keybed supports three distinct aftertouch behaviors, switchable per patch. Standard monophonic aftertouch applies uniformly across every held note, the way most keyboards have worked for decades. Polyphonic aftertouch applies pressure independently per note, which is already a step beyond the majority of synths on the market. FullTouch goes further still: instead of only reading pressure after the key has bottomed out, it captures expression across the key's entire range of travel, from the initial press onward. That gives a pianist or synth player a continuously variable gesture to work with on every single note, not just a binary "pressed then squeezed" motion.
According to Arturia's own documentation, this per-note data maps directly onto MPE, meaning the PolyBrute 12 behaves as a true MPE controller and sound source at the same time — a 61-note MPE keyboard that tracks position, pressure, and touch independently for every key you're holding down.
Doubled Polyphony, Same Expressive DNA
The PolyBrute 12 doubles the voice count of the original PolyBrute, jumping to 12 fully analog voices. That headroom matters for MPE players specifically, since expressive multi-finger playing tends to eat voices fast — pressing five notes with independent pitch, pressure, and timbre modulation on each one is a very different polyphony demand than holding a static chord. The extra voices mean richer layers, wider zone splits, and more natural polyphonic MPE performance without voice-stealing artifacts cutting through a expressive passage.
Under the hood, the architecture carries over the traits that made the original PolyBrute notable: dual analog oscillators, a choice between Steiner-Parker multimode and ladder-style low-pass filtering, and a deep modulation matrix that can route the same gestural data — pressure, aftertouch, the touch-sensitive Morphée joystick, and the ribbon controller above the keybed — to dozens of destinations simultaneously.
Split, Layer, and Route MPE Two Ways
For MPE-focused players, one of the more practical details lives in the PolyBrute 12's split and layer configuration. In Split Mode, the synth lets you allocate MIDI channels between an upper and lower zone — for example, splitting the available channel count evenly so both zones get independent MPE voices. That flexibility means the PolyBrute 12 can function as two separate expressive instruments at once, each addressable over its own MPE zone.
Connectivity covers both the traditional 5-pin DIN MIDI ports and USB, with MPE data transmittable over either, so the PolyBrute 12 slots into hardware-only setups just as easily as a DAW-centric studio.
Why This Matters Beyond One Synth
FullTouch is a useful case study in how manufacturers are still finding new interpretations of what "expressive" means within the MPE framework. The spec itself only defines how per-note pitch bend, pressure, and a third dimension (usually called timbre or slide) get transmitted over MIDI — it says nothing about how a physical keybed should capture that data. Arturia's answer, using the full key stroke rather than just the compressed endpoint, is a meaningfully different playing feel from the touch-strip and pressure-pad approaches used by controllers like the Expressive E Osmose or ROLI Seaboard.
For anyone building a hardware-based MPE rig, the PolyBrute 12 is worth auditioning specifically for that keybed feel — it's a fundamentally different gesture vocabulary than touch-surface controllers, closer to a heavily souped-up traditional piano action than a slab-style MPE surface. And because the expression data ultimately speaks standard MPE, patches built for a PolyBrute 12's FullTouch performance can still be recorded, edited, and replayed in any MPE-aware DAW, from Bitwig Studio to Ableton Live.