EXP F8R/XVI Eurorack expander: USB C, MIDI, I2C

Regular price $55.00

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2HP Output Expander for Version 2.x XVI and F8R fader banks


  • USB C connection for use as a USB MIDI device and configuration via web editor
  • 1x MIDI Output (TRS A, cable not included)
  • 4x I2C ports with rear panel headers for inter-rack connections
  • I2C ports are fully buffered for safe I2C connections
  • Status indicator LEDs (Power/ready/activity) 
  • Compatible with 1.xx F8R/XVI Devices (details below)


Connecting to your device:

Simply connect the 12pin ribbon cable to the 12pin header on XVI/F8R.  There is a key in the connector that will only allow the cable to be connected one way.  Its fragile, so please exercise care when connecting.  USB connectivity is for data only, the device will not power via USB, it must be connected to eurorack power at all times.

The 12pin header is available on 2.0 versions of F8R and XVI only (there will be a version number on the back of the module).  The device can be used with 1.xx devices as well, the 12pin ribbon connector will fit on the 8pin header on those devices.  Make sure the key is inserted into the keyway.  When used on 1.xx device, only MIDI and I2C is available, the USB feature will NOT WORK ON 1.xx devicesThe device does have a work around (below)


Operating instructions:

Activity LED: RED indicates start up, XVI and F8R have a 7 sec boot delay to allow for I2C communications to start correctly between devices.  The LED will turn green when it is ready to use.  LED will show activity (orange) when a fader is moved

MIDI: TRS A standard MIDI out.  MIDI CC# can be configured for the TRS MIDI Out via web editor.  Only 7bit CC MIDI messages are supported at this time

USB: USB MIDI OUT (only), class complaint USB MIDI driver.   The USB MIDI can be configured via web editor independently of the TRS outputs so different CCs can be sent out via the TRS and USB MIDI

I2C: Tip SDA, Ring SCL.   Each port has a corresponding header on the back for connecting modules via dupont cables.  Maximum cable length is 15in (38 cm).  Connecting devices via I2C is outside the scope of these instructions, please refer to the target device's manual for additional requirements.

Connecting EXP to 1.x devices:

Connect the 12pin connector to the 8 pin header making sure the key is located in the correct position.  This will enable MIDI and I2C functionality, NOT USB


To enable USB functionality, a Micro USB break out cable is required and a 0.1" pitch right angle header has to be installed onto the EXP board.  If you are unable to install the header, please contact Michigan Synth Works before purchasing and we can install one for you.

Break out cable:


Header and cable installation:


Note orientation of header wires, RED is on TOP