Programmable MIDI Foot Controller for the Korg KP3+

MIDI Foot Controller

The Korg KAOSS PAD KP3+ is a powerful beast. It’s great for realtime processing and sampling, but it’s not the best choice as a loop pedal. For one, the loop record length choices only include 1, 2, 4, 8, and 16 beats. You can adjust that after recording, but not on the way in. One shot samples can be any length, but they need to be triggered manually or via a sequencer. Furthermore, it’s not a pedal. If you want to trigger or record samples with your feet you’ll need a MIDI foot controller to do that. And not just any controller. It will need to be programmable so that you can send specific note values to the KP3+ that trigger each of the sample buttons.

This is the issue I decided to resolve for my continuously evolving live setup. More often than not I use a Rhodes electric piano with the KP3+ alongside a modest family of other gear. Playing two-handed while capturing Rhodes loops without audible gaps is impossible if you have to use a “spare” hand to do it. There are a number of programmable MIDI foot controllers on the market. Unfortunately, most of them are not fully programmable and are designed for changing patches versus triggering MIDI notes. An exception to this is the Behringer FCB1010, however, it’s quite large with twelve switches and two expression pedals. I only need four switches and can’t afford the space the FCB1010 would take up.

Highly Liquid MIDI CPU

People are making all sorts of custom MIDI controllers and there’s tons of microcontrollers that can be used for this purpose. I won’t get into all the options, but a few examples include Arduino (perhaps with a SparkFun MIDI shield), Teensy, Livid Brain V2 or Brain Jr, and Highly Liquid’s MIDI CPU. It just so happened that I had a Highly Liquid MIDI CPU on hand that I was sent to me as a sample years ago. I had used it for a few experiments, but nothing on a permanent scale.

Following instructions on the Highly Liquid website I was easily able to reprogram the MIDI CPU via sysex and start testing it with the KP3+. In minutes I had a prototype working that was triggering the sample buttons properly. With that piece confirmed I ordered four momentary foot switches and a sturdy aluminum enclosure. I measured and drilled all the holes for the four switches, DC power, MIDI in, and MIDI out. I soldered it all together and started using it immediately. I’m very pleased with the results and hope to use the foot switch for years to come. To an extent it is future proof because at anytime I can reprogram it via sysex through the MIDI input. A second reason the MIDI in is useful is because I can still send the connect device MIDI from another source (MIDI clock for example). This works because the MIDI CPU can be configured to mirror the MIDI in to the MIDI out while merging messages that originate from the circuit board. Handy!

This was an inexpensive, easy, and elegant solution to a frustrating problem. Custom MIDI controllers are getting easier and cheaper to build all the time. I’d love to hear about your DIY MIDI controller projects in the comments below. Thanks for reading!

Korg Volca Keys MIDI Out Mod


Recently I have been looking for a way to sync the Novation Bass Station II (BSII) and the Korg Volca Keys. So what’s the problem? They do not communicate without a third party. As the firmware stands on the BSII, MIDI clock is not sent via the MIDI out port. The BSII cannot be used as a master clock to sync other devices. Fortunately it can receive MIDI clock, but unfortunately the Volcas only have MIDI in. The Volcas have gate clock out, but the BSII doesn’t do gate or CV.

This is particularly frustrating because I bought both synths for an upcoming project and would like them to play well together. To get around this I have been using a third device to send MIDI clock to a thru box then taking outs from the thru to the Volca Keys and BSII. This creates a mess of, what should be unnecessary, cables and power supplies. The upcoming project involves travel and requires battery operation in remote locations without power, so this work-around is not acceptable.

My next thought was to build a MIDI clock box. There are a few examples on the market, but they can be expensive (except for this one). Fortunately DIY solutions, like the Arduino, are fairly easy to build. Another way is to use the Highly Liquid MIDI CPU. Sending the MIDI CPU a signal from a circuit with a 555 timer chip controlled by a potentiometer is a great solution. Using this technique I was able to sync the BSII from a test gate signal. I may finish building this anyway because I have all the parts and it’s an interesting project.

However, the ideal solution would be for these instruments to communicate without additional hardware. Novation has said that they might enable MIDI clock out on the BSII in a firmware update. This remains to be seen, so I can’t get my hopes up. As it turns out Korg, like with the Monotribe and Monotrons, made the Volcas very easy to modify. A simple MIDI out mod sends MIDI clock, note on/off, velocity, and more.

To add MIDI out one simply needs to attach a MIDI jack with three leads to clearly labeled solder points on the circuit board. There’s almost no room inside for a recessed MIDI jack, so I used some spacers and mounted the jack on the right hand side. This also keeps the MIDI lead away from the knobs for playability. Voila! It works beautifully. Thanks, Korg!

Synchronizing Music Technology at Slam Academy

I am teaching a class starting on November 29, 2012 at the Slam Academy in Minneapolis titled Synchronizing Music Technology. The first class class of the four session module is free to attend with no obligation. If you decide to take the module you are eligible to purchase a Korg Monotribe and Korg Monotron for $175. General admission and student pricing is available.

In this course we will examine ways to synchronize musical devices including vintage-to-modern MIDI compatible devices, as well as pre-MIDI analog instruments using CV (control voltage) and gate signals. We will also learn how to sequence and interface these devices with computer software making it possible to create studio and performance setups that integrate decades of music technology.

The Slam Academy is one of a handful of certified Ableton Live training centers worldwide. Most classes are around $200 or less for students and meet for three two hour sessions. I am very excited to be an adjunct instructor at this incredibly forward thinking school for electronic arts. If you’re in the area please stop in for the free intro class on November 29 or consider registering for a module or two.

Handmade Music Minneapolis Number Eight

Checkout the eighth installment of Hand Made Music Minneapolis on July 25, 2011 at 9pm at the Hack Factory.

This time the line-up includes Rifflord playing heavy music on handmade gear, Mike Hutchins talking about the same gear, Adam Loper playing his modified organ and leslie cabinet, and Dust Buns.

More information is available here