Keyboards have worked for centuries, but they restrict continuous expression and pitch. Touch is more flexible, but most readily-available touch controllers (like the iPad) lack pressure sensitivity. That leaves ribbon controllers. When do you don’t have quite what you want, you make your own.

Just ask Rasmus Nyåker of the Copenhagen Noise Lab. Rasmus writes us with copious details of his project, which he built just to get more enjoyment out of playing. It uses multiple ribbon controllers, aligned for easy access from the hands, with pressure sensitivity. He tells us how he built it and why. And if you want to build your own, he even shares parts sources.

(Side note: anyone remember M-Audio’s, nee Midiman, aborted Surface One?)

CDM exclusive: Demo of a DIY-midi-controller from Rasmus Nyåker on Vimeo.

I am pretty bored with keyboard-based synthesizers when it comes to my personal music. I find it uninspiring to use for synthesizer interaction. Been reading a lot lately about the ideas [synth pioneer Don] Buchla had in the 60s and 70s and arbitrary surfaces give me a thrill. Each sensor can control whatever I want. On my Snyderphonics Manta I am almost there – I don’t need ADSR [envelopes] as each key sends data depending on my movement that can control, for example, VCA [amplitude] or filter or both. I can use the same setup to slowly evolve and fade in chords while playing a fast melody with sharp transients and octave up using the same patch and at the same time. The sound creation moves from the machines onto my fingertips.

The Manta only supplies me with one continious controller per finger/zone/hexagon. It’s much like any polyphonic aftertouch keyboard in that way (I have a Roland A80 which is a marvellous controller as a keyboard). The Manta has two great things going for it, though: it is much more compact and I can route a separate CC-number from each of its hexagons. [Video examples of Rasmus playing the lovely Manta below.]

I am also a proud owner of two monomes [YouTube video of him playing these, too] — a walnut 128 and a GS64. Both are really splendid controllers for percision stuff like sequencing, arpeggiating, loop-control and stuff. It is a great way of getting to control multiple things at once that are buried in a computer-screen interface and the visual feedback is great. There’s a great community, too. It is, however, binary in its control: either you push a button or you don’t. In this sense, the Manta feels a lot more like an instrument.

The problem with both of these controllers is that they require a computer. I hate bringing a computer onstage, even if it is hidden underneath a table (My Nord Modular G2 is great, with multiple midi-CCs, and is usually my weapon of choice.) On top of that, I want to control more stuff with each of my fingers. So what do I do? Well, let’s build one.

I would like to add that the last musical device I built was an external filter I built on veroboard in 1994 when I was 14…

I researched on the Internet and found that the SpectraSymbol Softpot or Hotpot-positional sensors (ribbon-controllers) would be perfect for me. That’s one controller per finger. I also wanted something to sense pressure and found Force Sensing Resistors (FSRs) from Interlink Electronics that were 20″ long, but almost as wide as the ribbons and constructed so they can be cut down to size. I also needed something to convert the interaction with these to MIDI data. I found a good [MIDI data encoder] from Highly Liquid called MIDI-cpu. However, for the number of controls I wanted, I would need to daisy-chain two, so I looked around a bit more. Finally I decided on a Doepfer USB64, which works “off-the-shelf” and wouldn’t need much customization. I did a few sketches of the controller I had in mind in [Adobe] Illustrator.

I decided on using 4 inch / 10 cm hotpots for the device, as that would give enough length to play with while still being able to touch each end of the strips at the same time. Finally, I ordered all the sensors including FSRs from Sparkfun and a USB64 from With the free application Front Panel Express from Schaeffer I designed the front panel and ordered it directly within the application. I made the design as a three layer sandwich each using a 1.5 mm-thick sheet of anodized aluminium. I made the top-layer with cutouts for just the sensing area of the sensors, and counter-sunk for M3 screw-heads. The middle layer has bigger cutouts, leaving room for the full sensors. And the bottom layer has holes for the sensor-connectors.

As expected, the electronics got here before the panels. So I breadboarded one of each sensor-type to the USB64 and checked that it worked.

I continued by soldering the cable onto the sensors, making a veroboard for distibuting power, ground, and connecting lots of resistors. And then I decided to hook up a setup of four strips (4 hotpots and 4 FSRs) taped onto a tabletop — mainly for trying it out before I got the front-panels.

After a few days of waiting, a guy from UPS showed up with a big package for me. I started immediately to mount everything, and hooked it up to the USB64.

I checked the results with the MIDI input from the Nord Modular G2 and saw that I had some fluctuating data from the hotpots. So I decided to drop the ground on them, and instead let the signal output run to ground too, but via a 10K ohm resistor. That gave me only half the CC-range, but cleared the fluctuations; having a big jump in data when touching the sensors gave me ability to make programs in the G2 for which touch can act like note on/off, and initial pressure sets velocity level. Now I can theoretically get note on/off, velocity, pressure and position Control Changes from each of the twelve sensor-strips.

I milled an enclosure out of some leftovers I had of countertop oak from which I’d built my studio desk. It is the first thing I’ve milled, and I did it by hand, so it will need some sanding and finishing.

The next step was cutting out holes for the connectors, which I did with a Dremel, and cutting down a piece of acryllic glass for the bottom. The picture shows how it looks right now; the woodwork isn’t finished yet and the front-panel-sandwich is just lying in its place without being held by anything other than gravity.

At this point, I’ve spent around US$650 on it and 10 hours on construction and troubleshooting, plus lots of time deciding on function and design aspects. [Ed.: Not bad. Projects like this can be much bigger time and money sinks than that!]

I’ve recorded some demos of my first go with it:

These are minor scale-tuned oscillators; pressure controls the amplitude of each osc/strip and position on the ribbon determines how much the oscilliator belonging to the strip on the left will frequency-modulate the current osc. I ran everything through an eight-tap delay, with a separate filter per tap (5bp, 2lp, 1hp, but in a randomized order) and then some reverb… It gets really chaotic when I push a couple of neighboring strips, as the number of FM-operators influencing each other increase. It will take some time before I get enough control to really play this controller properly. But it is the most fun and rewarding thing I’ve been using in ages. The synth is the Nord Modular G2.

Sounds really like atonal trash, but even a simple FM patch gives a huge range of sound:

A more tonal thing now — sine oscillators, 2 per strip, tuned apart in intervals within a minor scale, for a total of 24 oscillators. Position controls amplitude and pressure controls the speed of a dedicated LFO (12 in total) and its amount of amplitude modulation. It is all transposable using a keyboard so I get more range. G2 again.

Lastly, I made an mp3 of a Karplus-Strong patch [physically-modeled string impulse] driven by the controller:

Position controls rate of an LFO sending impulses to a physical modelled string. Pressure controls amplitude.

Sources for parts:

Midi-encoders [as in processing, not knobs – Ed.]:


  • James

    Frankly, I'm more inclined to pick up one of these, or a manta before I ever considered a grid of the monome sort. Maybe I'm just repeating the 70s again when us disco roller skaters looked at skateboarders and thought "that'll never take off", but I just can't get into the square grids. That's a whole different story. What I do like about the manta particularly is that it uses a honey comb matrix. Let's face it, there's a reason why nature uses carbon as a basic structure and why my favorite board games use a hexagon grid. They're fascinating, immediately more musical theoretically than a grid. I like what Rasmus says about getting the music out of the machine and into the fingers.

  • guss

    I don't quite understand. Aside from not having to connect to a computer, what can this do that the manta can't? I thought it was fully programmable…

  • Guss: It does send 2 cc's per finger instead of one, so it is a lot more versitile than the Manta. The Manta does only send one CC per hegaxon and the difference between minimum and maximum value on that CC is pretty small physically, so it is very hard to control in a nice way. I like the Manta, but I love this controller. Having both position and pressure sense is soo much more expressive. The Manta could be replicated on an iPad with clever programming, this controller can't.

  • guss

    Ah, I see. I thought that the manta sensed pressure as well.

  • The Manta does only sense how much of each hexagon is covered up to 50% of the area, that's giving the maximum signal. And to be sure to hit the hexagon you will need to cover some area, which gives about 20% higher than the minimum CC value.

  • kind of reminds me of Madrona Labs' Soundplane, at least in the theory that musical control is in the finger, not the software.

    A keyboard is a great control surface for a piano, or similarly, any sort of mallet percussion. A synthesizer is in a different domain, and needs a different control scheme. But just as every synth can have multiple timbral personalities, its control surface should be equally as malleable. It all depends on what you're trying to do. Sometimes a sequencer is the best tool, sometimes a keyboard, but I think there needs to be other options.

    In other words, this guy makes me very happy.

  • I do remember the Surface One. I actually got to play with a prototype while visiting my friend who was building it at Tactex in Victoria, BC, Canada. I still think it was a mistake that they never produced it. It would have been well ahead of the curve for the time.

    As I remember it, it used the same fiber-optic technology as the Canada Arm on the space shuttles. Each touchable area was fed with hundreds of fiber-optic lines that had some known time for the path from an emitter to a detector. By applying pressure to the pads the substrate through which the light passed changed so that the light took longer to travel its path. This allowed the fingers of the Canada arm to be incredibly sensitive and would have made for incredible control in the Surface One.

  • nicola

    this controler is superb!
    it's like the buchla unit tactile sensor!
    can be used in a modular synth sistem?

  • I remember the Surface One from pics in Keyboard magazine. never saw one. I heard they couldn't make the pricepoint realistic. I believe the Buchla Thunder predated it.

  • anechoic
  • Eport

    The Manta is nice step but I need smaller 'keys' and a lot more of them like my converted AXiS-49 ( The hex grid (especially when oriented in the Wicki-Hayden note layout) is a brilliant design and I would highly recommend anyone to do more research on them.

  • midihendrix

    very cool, but for now i will stick with my pressure sensitive ribbon controller of choice….. technics 1200s 😉

  • vanceg

    I like the fanned fingers – Similar to the Buchla Thunder. I bet this is very comfortable to use. Having location and pressure both on one controller makes for some wonderful expressive possibilities. Well done.

    The Surface One and the related Tactix material would have made great audio/video control products…if they'd made it to market.

    Right now I'm really looking forward to the SoundPlane, the prototypes I've seen really have me excited about this potential!

  • really nicely done, kinda stribey

  • Andreas

    Hey this looks great, Rasmus!

    I'm a big Lemur/MaxMSP freak who had PostDanmark lose my Manta in the mail, never to be seen again 🙁
    I'm moving to Østerbro in January and would love to pick your brain about geek stuff like this – 
    Get in touch!
    wetterberg at gmail

  • Thanks everyone. The greatest pleasure of the project is however playing with the controller! 😉

    Andreas, just drop me a line at info (at) kufrec (dot) com when you have managed to get settled.

  • Nice.  That's exactly how I did my touchboard:

  • Spazmatron

    The "appendage" ribbon controller by Scott Stites also uses the softpot. It's more of a monophonic synth controller, but with tons of crazy features. If you're interested in ribbon controllers, its the one to see. 

  • The range of the Manta's "pressure"/area sensitivity is pretty large, and it just takes some skill to learn how to land your fingers on a pads. It's quite a lovely instrument to play, and once the forthcoming Manta Mate is released, it won't require a computer to operate as well. 

    I recently toured for five weeks playing nothing but the Manta and some drums. It was great to control synths without a black & white keyboard.&nbsp ;

  • Andreas

    Pay close attention to Christopher Jon – he's got some ninja-chops, too! 🙂

    Rasmus: Noted! Now I'll be packing again!

  • Hi, This is Jeff Snyder, the Manta designer. Glad to see this article, thanks Rasmus for the press! I really like your slider controller — and I'll be in Copenhagen in late December, so maybe we can meet up – Andreas, are you near Copenhagen at all? Yeah, the new MantaMate that I'm prototyping right now will allow you to use the Manta and other USB devices without a computer, and will also include a lot options of analog synth control.

  • rich

    I'm seriously looking at the Manta (I'm considering selling my spds to get it). But I'm also thinking, as was mentioned above, Why not just get an ipad, surely a Manta clone is just begging to be developed, let alone all the other potential ipad has for interface design (plus they're the same price).

  • Jeff: Thanks! Just drop me a line on my email info (af) kufrec (dot) com or a text at +45 429 429 44. I'm pretty flexible as I make my living from writting crap-music nowdays…

    Rich: An iPad is still an iPad, it won't give you the tactile feedback that the metal do give you as the hexagonal zones actually is something that you actually can feel. The iPad is great and I think you should get one, but I'd wait for the next generation if I were you. The Manta however is bound to raise some more eyebrows on stage and the Manta-object in Max is a pure pleasure to work with and the limitations of just one interface layout may make it even more interesting to work with and costumize for your personal needs. A bit like buy an MS20 or an iPad with the iMS20 app…

    The reason I believe that we don't see more manta's out in the wild is that most of the potential buyers comes from the monome-community. I know I did. With the monome we have a pleteora of applications that is part of the attraction of the device. With the Manta there is not that many applications availible. This alone kept me from getting a Manta for quite a while. But once I've got mine I realized that it was a strange reason. The monome with all it's restrictions that comes from being a binary-controller is only getting usable when you costumize it in a more complex way. The Manta however is usuable straight out of the box. The simple midi-route applications for Max provide enough costumization to keep you (and me) happy and creative for ages. Just being able to easily map notes and CCs individually without programming is great.

    Think about it like a polyphonic-aftertouch controller for under 1K$. The ability to customize feedback and notemapping and use the terrific Manta-object in Max is just a super-great bonus. Great value for your money.

  • rich

    Thanks Rasmus. You make some good points. I'm swaying towards the Manta again. Love your controller too btw. I am in awe of any knowledge of electronics let alone something like that! Awesome.