MIDI control of analog devices from Michael Una on Vimeo.

John at HighlyLiquid has been busy this year- he’s got a new kit out and one in the works that really step up the game. You may be familiar with his previous kits, which add MIDI control to Speak & Spell, Atari 2600, or pretty much every Casio. HighlyLiquid also stocks more open-ended kits which can add MIDI control to pretty much anything- I used one in my MAKE Magazine article last year to build a drum-playing robot.

The new MD24 falls into the latter category. It takes a MIDI input and gives you 24 discrete +5V outputs that can be used to drive relays, transistors, or servo motors. Functionally, the MD24 is similar to HighlyLiquid’s MSA-T or MSA-R kits, except that you now have 24 outputs instead of just 8- a significant improvement.


Certainly, people with a lot of time on their hands will say “I can do that myself with Arduino, running MIDI through the USB-to-serial converter, and I’ll build a custom Max/MSP patch to control the parameters.” Sure you can, but personally I prefer to spend only as much time as it takes to get my musical systems up and running, instead devoting my time to actually making music and practicing my live set. If you are like me and love DIY stuff, but also don’t want to spend 6 months programming your own ATMEGA chips, then I recommend you consider this type of solution.

I found the kit very easy to assemble. The board is laid out with a decent amount of space between the components and is clearly labeled. The online instructions were very thorough and identified any potential problems. I was able to assemble the kit in about 40 minutes and I was able to hook the MD24 up to my handmade sequencer synth very quickly. It all worked on the first try. (Disclosure: I’ve built one of these kits before and pretty much knew what I was doing, but I didn’t find it all that difficult the first time I did it either)

4 kits

I made a little video to demonstrate the system in action, which works a lot better than trying to describe it with text. (See top)

My conclusion: The HighlyLiquid MD24 MIDI Decoder kit is a very affordable, powerful solution for all your analog sequencing and control needs. My imagination was really sparked by this one, and the potential applications are immense. HighlyLiquid bridges the gap between the analog and digital worlds very elegantly and with a minimum of time and fuss- 100% win.

MD24 MIDI Decoder kit: $44.95 at HighlyLiquid.com

And, a teaser: There’s a DIY MIDI controller kit in the works which looks totally awesome. I hope it’s released soon because I got all kinds of plans for it.

  • Armando Cajide

    boom! i have been pondering when this would happen. big cheers from over here.

  • Based on the description, this doesn't sound like it would work for MIDI->CV applications, unless I'm missing something.

  • robb

    I can see the appeal, though what I'd reaaaky like to see is something like this that has an RJ45 plug and talks OSC.

  • Michael Una

    @Robb – that's a joke, right? Sometimes with this crowd, it's tough to tell.

  • robb

    No, not at all.

    I’m fed up with midi 😉 and this should be quite possible to do

  • Jaime Munarriz

    Any cue about Korg analogs? They use a different standard, instead the usual V/Octave, I don't remember exactly…

    Do you think they can work with this?

    (I love my MS20)

  • Michael Una

    Hi Jamie. This type of kit would work for your MS20 if you use it to trigger the switches for the notes of the keyboard. You might need to use some transistors or reed relays in between, but this way you'd have control over 2 octaves.

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  • Hey….very cool! Can you explain how it's interfaced with random sound objects?

    I have a circuitbent Heathkit tube tone generator with a sync input, would this work for that?

    I love it's sound..very dirty! …really want to sync it somehow!

  • stk

    Cool stuff, 'though I'm more interested in their MPA MIDI Decoder – 4 x Potentiometer Output.

    Gonna MIDIfy my Space Echo!

  • Ursakin

    'instead devoting my time to actually making music and practicing my live set'- hail!

  • aidan

    so is this a solution for MIDI->CV applications or no?

  • Michael Una

    Aidan- this kit doesn't do MIDI–> CV on it's own. However, it does provide MIDI control over 24 independent 5v channels, which could be used to switch on and off some kind of external voltage controller. I'm familiar with the theory of CV but not the practice- I assume you could quickly build a set of circuits at different voltages and use this kit to turn them on and off via MIDI.

  • Otterfan

    Just to clarify, this is not a MIDI>CV converter—at least not the traditional kind. It converts digital MIDI messages to digital 5V signals. There is pulse-width modification for controlling servo motors, but you couldn't control the pitch of a CV synthesizer with much accuracy. You can use it to send triggers and gates though.

  • aidan

    cool. might be a useful addition to this then…


  • " robb

    No, not at all.

    I’m fed up with midi 😉 and this should be quite possible to do "

    Rob serious.. stop beating a dead horse.. I think this post might have surprised many coming from Peter.. but the truth is.. most of us who are working with OSC also work with MIDI.. even MLR has midi short cuts.. you know the most popular monome app written by Brian himself.. I applaud Peter for recommending the right tool to get things done.. being more "l33t" does not make your music better.. Better music makes music better.

  • S Ford

    Why the f*ck did I give away my Casio SK-5?

    I'm a f*cking moron.

    Sorry for the swearing, I'm pretty p*ssed off with myself right now.

  • aidan

    yeah i noticed the midi retrofit kit for speak and spells. just the ticket for the untouched s&s gathering dust in the corner.

    hints will be dropped in time for christmas…

  • robb

    I agree, this has anything to do with quality of music or l33tness.

    The "I’m fed up with Midi" comment was not really related to hardware but the ongoing issue of MIDI in Java on OSX which pretty much breaks the cross-platform appeal of the language.

    That is really annoying to me, sorry, i didn’t mean to diss

    MIDI is by no means a bad protocol, but it is closely tied to western notes, sending a D#3 to make a Speak&Spell say Q is not really what it was designed for.

    If you live in a pure MIDI ecosystem, that’s fine but I bet most people reading this blog probably have a computer with ethernet on stage anyway.

    I wonder why so much engineering effort is put into working around its limitations when cheaper and more adaptable alternatives already exist.

    Everyone uses network technologies, a solid UDP stack is of high priority to every OS, why not benefit from that?

    "but the truth is.. most of us who are working with OSC also work with MIDI"

    I think the problem is, most of us who are working with OSC also have to work with MIDI

  • I can see the appeal for a DIY project, But for midi to CV you can't beat kenton devices http://www.kentonuk.com/

  • In addition: The CV task at hand is a big factor to consider. Not all midi to CV devices are created equal. Midi to CV triggering is very different from pitch tracking. Comparing the midi to CV accuracy in my flame clockworks & moog voyager you will find variation.

  • seb


    You have to see MIDI as a protocoll that is cheap and easy to program, It serial and can be handled by most Microprocessors. OSC on the other hand is a high level protocol. Intern in a PC not a big deal, but when you are building hardware that people are going to wanna buy, the OSC is still going to cost you, For such a DIY project the cost of an Microcontroller that can handle OSC is still to high.


  • seb

    When i think about it, its like serial VS USB. The monome for example is still an Serial (USART) device, its just translated to USB like one of those Good old RS232-USB converters. The OSC part ist all taking place in the host computer. To you its all OSC, but in reality its good old Serial (MIDI) doing its thang. So i bet most of the OSC Robb is working is intern.

    But it will all be OSC in a year or two, if peak oil does'nt catch up on us!

  • robb


    The Monome way of doing things is quite nice. OSC all the way, serial for the last mile. full ack.

    Now I really want to know how well the obviouse arduino/ethernet shield combo would perform on UDP OSC…

  • Charlie Lesoine

    The 24-Input MIDI Controller sounds really awesome. Does anyone know – would I need something like this to process midi DATA if I am doing an arduino project? Or can it all be done within the arduino? I am a noob.

  • Props for the killer SN76477 build. I bought one from BGMicro.com a while back, and promptly bought 3 more after playing around with it a bit. Right now I'm working on getting it set up so that an Arduino can control all of the resistor values with MOSFETs.

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  • It was nice to Know about MIDI and the video posted in the post is superb.