Introduction: RetroFit USB Midi & Digital Audio to a Korg MS2000R Synth

By www.facebook.com/dane.d.henry

Some may want to 'burn me at the stake' for drilling holes into a piece of now becoming vintage kit.. But for me as I frequently use my Korg MS2000r with modern tech, I felt it lacking and needed something to make life easier in terms of connectivity (that is 2 x Midi cables, 2 x Audio cables (L/R) and an external soundcard!!).

I decided to add USB Midi functionality and Digital Audio Out which now means I don't need an external soundcard and a myriad of wires all over my desk..

Step 1: Stuff Needed

  • Korg MS200r (duh!)
  • Arduino UNO (must have ATMega16 NOT PL203 serial thingie!!)
  • Hole Cutter
  • USB Socket
  • Some Wire
  • A way to program the Arduino boot loader (I used my GQ4-x programmer not necessary but = quicker!!)
    • Schematics are always good :)

    The hole cutter was the most expensive item on the list at a whopping £10 from Maplin!!.

    The Arduino and other items were all bought off ebay.

    Step 2: Program Your Arduino Bootloader

    I love these little things!!!

    I used my GQ-4X programmer to flash the AT16 using the ICSP header on the Arduino as I found it easier but there are other ways of doing this.

    I've attached 3 files

    "OrigATMega16u2.bin" is the original ATmega16 bootloader (just in case!)

    "USBmidiKorg.bin" this is the USB Midi bootloader with a custom USB descriptor for the MS2000r.

    "Arduino_midi.hex" this is the original USB Midi bootloader taken from The HIDUINO project

    Attachments

    Step 3: Wire It All Up

    So here's how everything is connected..


    MIDI IN/OUT
    Full Preview

    KORG ---------> ARDUINO

    MIDI IN pin(4) -> RX

    MIDI IN pin(5) -> GND

    MIDI OUT pin(4) -> TX

    MIDI OUT pin(5) -> 5v

    Forgive the crudeness but it works.. I had to connect the MIDI IN to the 5v and TX on the Arduino (I should really use an optocoupler)

    AUDIO OUT (optional)

    Using this analog to digital converter, I can actually connect the Korg's audio directly to my Mac with no quality loss and get a stereo signal with one cable.

    I used the headphone output as I found the main audio out likes to have something plugged into it (think its a L/R->Mono or L/R->Stereo sens thing!!) I also used my trusty multimeter to find a good 5V (shown on the last image) to power the converter

    Step 4: Test... Then Glue...

    So now it's time to plug in the power supply, usb, digital audio and fire up your DAW (I use Logic X).

    If you've done everything correctly all should work!!

    A little bit of cable management and some glue to secure the usb and the coax connector...

    Step 5: Cup of Tea!!

    I love a good cup of Yorkshire Tea!!!

    Were all done.

    There are a few things that I could improve on starting with:

    • A better analog to digital converter with a selectable samplerate as the one I have is locked to 48Khz.
    • Using an optocoulper for the MIDI OUT.
    • The whole a little less crude but it works for what I need so......