New Korg/littleBits Synth Modules


Getting Started with MIDI, CV, and USB I/O

The newly released MIDI, CV, and USB I/O modules were designed with the engineers at Korg in order to add connectivity between the Synth Kit and other electronic musical instruments.

Since the launch of the Synth Kit in November 2013, many users requested the addition of modules that would allow the Synth Kit to be connected to the rest of the equipment in their music studios. Our teams at littleBits and Korg agreed that adding this functionality would unlock additional power from an already rich musical experience and set on designing them.

The areas of focus for these modules would be MIDI instruments and controllers, computers, and analog synthesizers. For those familiar with music technology, these modules and their functionality will hopefully be self-evident. For those new to the field, the following will act as a quick primer and tutorial guide for the modules and their connection to electronic music tools.


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The MIDI module allows you to control the Synth Kit from MIDI-enabled hardware instruments and computer software (Ableton Live, Pro Tools, etc). Additionally, it will allow you to create your own MIDI controller with littleBits modules by converting littleBits control voltages to MIDI messages.

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MIDI (Musical Instrument Digital Interface) is a serial communication protocol for electronic musical instruments. First introduced in 1983, MIDI has been and continues to be a mainstay in electronic music production. MIDI does not sound like anything but MIDI note numbers and messages represent sounds and actions that can be played by sound generating devices like synthesizers. The simplest way to think of it is as a code that electronic musical instruments can understand. A number represents each musical note and this information can be sent to and from electronic instruments. There is also a timing component, or MIDI clock, so that they can play in sync with one another.

The MIDI module can both send and receive MIDI messages. We’ll walk through how it does this:


When the mode switch is set to “in”, the MIDI module can receive MIDI messages from two kinds of sources. Using the included adapter cable, the MIDI module can receive MIDI messages from hardware controllers over a standard 5-pin DIN cable.

One end of the cable is connected to the MIDI module and the other end of the cable is connected to the MIDI Out port of the controller being used. If that controller is a piano keyboard style controller, playing notes and melodies on the keyboard will produce notes from the Synth Kit. Any of the circuits from the Synth Kit booklet that use a keyboard (or micro sequencer) module can have the keyboard replaced with a MIDI module to allow you to control the circuit from your MIDI controller.

Similar to the keyboard and micro sequencer modules, the MIDI module has two outputs: A main bitSnap™ output that sends control voltages to the other module (like an oscillator) depending on which key is pressed and a trigger output that sends a 5V, HIGH signal out to modules (like an envelope) when any note is pressed.

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Like with the keyboard module, the oscillators will need to be tuned to play the correct pitches. See the “Tuning” project in the Synth Kit booklet for more information. To help with tuning, standard digital instrument tuners can be used and there are many tuner Apps available for smartphones.

The MIDI module is also able to receive MIDI messages over a USB connection. Simply, connect the included micro USB between the MIDI module and a computer. Before you being playing, there may be a few more steps to get your computer sending MIDI messages to the module depending on your operating system and DAW (Digital Audio Workstation).

To begin with, you can download the Korg USB MIDI driver here:

Installing the MIDI driver is not necessary in most cases but may help setup, especially in Windows systems.

In your DAW of choice, go to the preferences panel and make sure that “littleBits Korg w5 MIDI” is enabled. When you have created a MIDI capable track, you should select its output as “littleBits Korg w5 MIDI.” By sending MIDI data from your DAW, you should be able to hear the notes played back through your synth modules.

If you have more than one MIDI module connected to your computer, they will be numbered sequentially, appended with #2, #3, etc. The MIDI messages will be sent via MIDI Channel 1 and only Note On/Note Off messages will be received. Continuous Controller messages (MIDI CC) will not be received. This includes Pitch Bend.

It is also possible to control littleBits modules with a tablet or smartphone. By using the MIDI module with a USB connection device (Apple Camera kit for iOS), you can send MIDI messages over USB. Little MIDI Machine is a free sequencer for iOS.

The module will stay powered while plugged in via USB but will not provide power for the rest of the littleBits modules in the circuit. A blue power module is always required.


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MIDI Out mode works by converting voltage signals generated by littleBits to MIDI messages. On the MIDI module, MIDI Out is only available over the USB connection.

Start by setting the switch on the module to “out” and connecting it to your computer via the micro USB cable. In your DAW, create a track that has a virtual instrument on it and set it to receive MIDI input from “littleBits Korg w5 MIDI.” It can be any type of sound, either synthetic or realistic; like a synth or a violin, or even a drum kit. Now connect a power and input module before the MIDI module.

The input module used can be a keyboard, micro sequencer, or even something outside of the Synth Kit like a slide dimmer or pressure sensor. When interacting with the input module, you should hear sounds coming from your computer.


The USB I/O module allows you send and receive digital audio and control voltages to and from a computer. When using in conjunction with a DAW, you can record your Synth Kit directly into a computer without the need of an external audio interface. You can also send audio from a computer into the littleBits system to manipulate it, for example with the filter and delay modules.

The USB I/O module is DC coupled which means that in addition to sending and receiving signals like music, it can also send and receive control voltages. This allows you to use software programs like Max, PD, and CV Toolkit. In these programs you can create “virtual” littleBits modules like sequencers, low frequency oscillators, and much more.


To use the USB I/O module as a recording interface for your DAW, set the mode switch to “out” and put it at the end of your synth circuit. Connect the module to you computer using the included micro USB cable. Depending on your DAW and operating system, you may need to plug the module in before opening your DAW program.

The module will stay powered while plugged in via USB but will not provide power for the rest of the littleBits modules in the circuit. For those using Windows operating system, the Korg ASIO USB Audio driver can be downloaded here:

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Like the MIDI driver, installing the audio driver is not necessary, but may help performance in some Windows systems.

In your DAW preferences, go to the Audio setup and select “Korg 2ch Audio Device” as the audio input device. You can only select the device to be either an input or an output at one time so select “Built in Audio” or similar as your output device.

Now just create a track to record on, arm it, and press record to start tracking audio directly into your DAW from the USB I/O module.

If you want to send control signals from your littleBits modules into software like Max, the same setup applies.


To receive audio or control signals into your littleBits setup, set the mode switch to “in” and put it at the beginning of your synth circuit. Then, setup your DAW preferences as previously mentioned except specify “Korg 2ch Audio Device” as your output device and set your input device to “built-in” or none.

If you change your computer’s overall preferences to enable “Korg 2ch Audio Device” as the output device, you can, for example in Mac OS, play music directly from iTunes.

If you want your littleBits modules to receive control signals with from software like Max or CV Toolkit, the same setup applies.

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 CV stands for “control voltage” and is a widely used term in the realm of analog synthesizers. A control voltage is a variable voltage signal that is used to control module behaviors ranging from the pitch of oscillators to the cutoff setting of filters and more. 

The CV module can be used for both CV and Gate/Trigger type signals used in analog synthesizers. The module is suitable for interfacing with modular analog synths, analog keyboards, as well as groove boxes like the Korg Volca series. The “Sync” ports employed in the Volca series of synths can be used to make your littleBits modules play in sync with your Volcas or vice versa. The 3.5mm connection jacks should be used with mono 3.5mm plug phono cables.

In relation to tuning practices, most synthesizers utilize a 1-volt per octave scaling, which means that a single octave of notes can be represented in a 1-volt span (1 to 2 volts for example). A notable exception to this practice is the Korg MS-20 and the new MS-20mini. Because of this, we have included a switch that selects between 1V/octave scaling and Hz per Volt scaling (the scaling system employed in the MS-20).


The CV module can scale incoming voltages as high as 12V down to the 5V system the littleBits system employs.

To use the CV module to control your other littleBits modules, connect the control device to the “CV In” jack. CV signals that come in through the "CV In" jack are routed to the output bitSnap™. The "CV In" jack is a switching jack so that any CVs coming in through the input bitSnap™ are not routed to the bitSnap output.

When using the CV module as an input, you can control the pitch of oscillator modules, the cutoff of filter modules, trigger the envelope module, or control the speed of the micro sequencer module (put the micro sequencer into “Step” mode for this)

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 CV Out

To use the CV module to control your other CV enabled synthesizer equipment, connect the control device to the “CV Out” jack.

CV signals received from littleBits modules at the input bitSnap™ are routed to the "CV Out" jack and the output bitSnap™.

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