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Page 2: Keith McMillen Instruments K‑Board Pro 4

Expressive Keyboard Controller By Robin Bigwood
Published December 2019

Playing The K

The experience of finally getting down to it and using the KBP4 in anger is likely to vary a lot from player to playing, depending on what you're wanting to get done, and their mastery of keyboard technique in general. But a few things soon become abundantly clear.

Monophonic, melodic, solo-style playing generally comes off very well. You're free to really concentrate on finger placement, to fully explore front-rear position, and to start using vibrato like a violinist might. Both fingerprint ink rolls or whole finger-pad slides can work well for vibrato, but I found it much harder to generate and control on sharps than on naturals, because of their much narrower width.

Playing with one finger in each hand is also fruitful, for similar reasons of agility and freedom of movement, and the split keyboard capability comes into its own here, to allow independent MIDI comms and touch response either side of a split point. While one hand is doing a static drone (say), the other can be generating vibrato-rich melodies, surges and goodness knows what else. Try doing that with your moving-key controller!

The X, Y and Z key response can steal the show for this kind of usage, but we shouldn't overlook velocity response. The finesse, gradation and repeatability that's possible is remarkable given the unpromising, unyielding key surface, and the KBP4 senses release velocity beautifully too if you can find a way to use it, and a synth that'll understand it.

The K‑Board Pro 4 Editor application, seen here niftily running in Google's Chrome browser, can be used to switch between basic modes of operation as well as drill down into the detail of expressive response. The finger touch point visualisations are clearly visible, as well as the lower tabbed area, which has three divisions for Keys & Zones, Sliders & Pedals, and Advanced settings.The K‑Board Pro 4 Editor application, seen here niftily running in Google's Chrome browser, can be used to switch between basic modes of operation as well as drill down into the detail of expressive response. The finger touch point visualisations are clearly visible, as well as the lower tabbed area, which has three divisions for Keys & Zones, Sliders & Pedals, and Advanced settings.

Overall, what's possible with the touch response is liberating, exciting, and nicely suited to straightforward synth playing, soloing, and perhaps also rhythmic and percussive programming. The KBP4 would not be on my shortlist for doing much serious acoustic or electronic piano playing though: for that hammer-action, moving key controllers are still far superior. I doubt many SOS readers need me to tell them that, though.

As for more advanced keyboard styles generally — chords, rhythmic arpeggiation, contrapuntal stuff and jazz/licks, and anything fast and intricate — good results from the KBP4 are less certain. For one thing, you'd better have a pretty splendid technique to avoid lots of splats with neighbouring notes. On a conventional mechanical keyboard a lot of subconscious finger position information comes from brushing up against notes around the ones you're currently on. On the KBP4's slim, flat, inert keys, much of that info is unavailable, and in noodly passages or amidst thick chords it's all too easy to fall out of position, and for the full Les Dawson effect to ensue (British readers of a certain age will get the reference — everyone else, Google). Full chords well into the keys, amongst those spindly sharps, are particularly challenging, and the tighter octave spacing does not help.

Still, as a keyboard player I personally found the KBP4 easier to get going with than any other MPE controller I've experienced, simply because the discrete-key design is more familiar and guides the eye better. A Seaboard isn't far behind, but the K-Board is clearer.

The down side of the discrete keys, which you may or may not regard as considerable, is that they don't support wide-interval glides in the Theremin, Ondes Martenot or pedal steel manner. Even the Linnstrument with its apparent discrete pitch-squares beautifully interprets finger slides up and down the rows as monster pitch-bends. Seaboard players can generate finger bends of any interval at will, or indeed zoom around on the flat surface in front of their raised key undulations. On the KBP4 your only real option for glisses and fall-offs is to configure a slider for Global Pitch-bend and use that in conjunction with held notes. It's a much less intuitive and controllable gesture, though, and affects all notes in an entire zone, which doesn't seem very MPE.

Judgement K

It may have had a long gestation, but the K‑Board Pro 4 has come into the world capable, mature and beautifully finished. It's a valuable new addition to the MPE ranks and absolutely has to be on any shortlist that also includes a Seaboard RISE, at the very least.

Sure, there are some things I could imagine being a little different. The multi-functional slider strips are flexible and do their job perfectly, but some kind of label for each, even a two digit LED displaying a simple acronym, would give all of us without eidetic memory a fighting chance on stage.

I've already mentioned the pros and cons of discrete keys: my personal preference for a continuous surface hardly matters, because there will be as many people that prefer the reassurance of the more conventional approach and layout. Potential purchasers definitely need to think this over carefully though: it goes to the heart of how you interact with your controller.

One little point: the KBP4 doesn't seem to have an option to send an All Notes Off panic message, which given the thick gobs of MIDI data it can generate is potentially an alarming omission. Thoughts of lunging for power sockets on dimly lit stages spring to mind... KMI told me they'll consider adding it in a future firmware update, though.

The value for money aspect of the KBP4 is one of those things that's very much in the eye of the beholder. The £749$895 typical retail price is about £550$600 too much if all you're really in the market for is a plain vanilla mechanical key four octave controller. If MPE appeals, though, you have to budget for it accordingly, and then the KBP4 is one of the most cost-effective options. There's no question it's beautifully made too, and that goes for the configuration software just as much as the striking, elegant and confidence-inspiring hardware.

MPE is taking off, no question, but still represents a niche in the market. The K‑Board Pro 4 is a nicely conceived, balanced all-rounder that'll let you explore that niche, looks like it'll be able to adapt to future developments, but can also turn its hand to general MIDI control duties.

Hardware Store

KMI's £50$59 MIDI Expander box is a utilitarian little thing, but provides everything you need to use your KBP4 in a DIN MIDI environment, and thereby perhaps break free of computer shackles.

One obvious way to use it is as a dedicated 5-pin MIDI Out for your KBP4. Just run a USB lead between both units' Expand sockets. The Expander will power the KBP4 this way too, if you plug a USB power source into its POWER socket, and helpfully indicate MIDI activity with front–panel LEDs.

Equally, the Expander can be powered by the KBP4, if the latter is powered via its own USB socket, from your computer, say. A DAW will see it as an extension of the KBP4, essentially as a one–in/one–out MIDI interface, which is handy for all sorts of things There's no way I could see, though, of preventing the KBP4 directly addressing the Expander's MIDI Out at all times, so you may still need a separate MIDI interface to incorporate hardware synths in a DAW setup.

Broad Base

MPE is clearly a massive part of the KBP4's raison d'être, but it caters for more conventional MIDI implementations too. You can turn off multi-MIDI channel MPE completely, or disable responsiveness of individual touch axes, to leave the K-Board as just a straightforward velocity and (channel) aftertouch controller with a couple of sliders taking the place of pitch-bend and mod wheels. Or, acting in a simple single-channel mode, you might enable Poly Aftertouch for Z axis pressure, for synths like the Sequential OB-6 that can respond to it, even if they aren't fully MPE compliant. It can take a bit of experimentation but all sorts of things are possible. For example, I got beautifully expressive results driving a Nord A1, a four-part multitimbral synth that doesn't even respond to aftertouch, by configuring the KBP4 for four channel MPE and configuring the axes of touch for useful parameter CC messages.

The DAW MPE compatibility situation is mixed. Logic, Cubase, Reaper, Bitwig and a few others will host MPE-compatible soft synths and more importantly record multi-channel MIDI into single tracks. Live, DP, Pro Tools and Studio One can't currently handle multi-channel MIDI into single tracks, and although there are multi-track workarounds they tend to be pretty clunky.

Ideal soft synths include Serum, FXpansion Strobe2, KV331 Synthmaster, many of Logic's bundled synths, ROLI Equator and Madrona Labs' Aalto and Kaivo. On iOS you can add Moog Model 15, Minimoog Model D and AniMoog to that, amongst others. In the hardware world, anything multitimbral can be made to work, but true MPE-compatibles are few: Black Corporation Deckard's Dream is one, along with the Modor NF‑1 and the Modal 00-series. At the time of writing the only others that once fitted the bill — Audiothingies MicroMonsta and Futuresonus Parva — appear to have been discontinued. Various more mainstream analogue polysynths with discrete voice chips (including DSI Rev 2 and Moog One for example) seem prime MPE candidates, but none has been suitably equipped in firmware yet.

Generating Vibrato

Generating vibrato on the K‑Board Pro 4 involves wiggling fingertips from side to side. But you may well ask, what happens if you finish your wiggle on the low or high side of the key? Does the note continue on out of tune? Not necessarily, is the answer. By default, initial key strikes generate an in-tune note even if you play the key in the centre, to the left, or to the right. Then, when you begin to wiggle, the K-Board interprets the position change so that any additional movement to the left or right relative to the starting position results in flat or sharp pitch-bends. Clever! When you stop wiggling, pitch-bend by default goes back to 'in tune' regardless of whether your finger has ended up high or low of centre, and at a user-controllable rate.

With all this going on, you should always be able to play the K-Board Pro in tune, while still enjoying tactile, responsive finger vibrato when you need it. Interestingly, though, all the assistance systems can be turned off, which leaves the KBP4 capable of hideous (or perhaps beautiful, to some ears) microtonal cacophony. There's also an interesting 'Release Zero' option that pulls the release phase of notes into tune even if your finger leaves the key mid-vib, in an out-of-tune position. That's the ultimate in flawless intonation, but does away with the possibility of key-generated fall-offs or 'doits'.


  • Discrete-key piano-like layout ensures instant familiarity for keyboard players.
  • Fine, controllable touch response on multiple axes.
  • Configurable real-time controls, pedal inputs and touch response, via Mac, Windows and browser apps.
  • Scope for computer-free use via the optional MIDI Expander box.


  • Discrete-key design precludes a whole range of pitch-related gestures easily achieved by some competitors.
  • Vibrato easier to generate on naturals than sharps.
  • Unlabelled control sliders are fine with 'heads up' configuration software in the studio, but less welcome on stage.
  • No integrated hardware MIDI Out, and 3.5mm pedal inputs require the use of (included) adapters.


A distinctive new face in the MPE MIDI controller market that can work in DAW setups and hardware live rigs alike. Robust build quality and excellent programmability promise a long and varied working life.


£749 including VAT.