USB Bridge A

USB device and TRS midi router and merger

Description | Specifications | Order online


USB Bridge A allows you to connect 2 midi USB devices and one conventional MIDI device. Midi data is routed between devices and merged if necessary.

You can use this to:

  • Connect one or two midi USB midi controllers/keyboards to a conventional midi device
  • Connect a keyboard to a module with only USB device capability
  • Connect a cheap usb midi interface and get more conventional midi IOs

LEDs show the status of USB and midi:
NO USB device connected: off
USB device connected successfully: green
Receiving midi: flashes yellow
USB device connected, but not compatible: red
Overcurrent detected: blinks red

TRS midi LED:
Module is powered: LED green
Receiving midi: flashes yellow

Voltage converter

USB bridge A includes an optional DC/DC converter to convert 12V to 5V. This means eurorack cases without a 5V supply are also supported. A jumper on the back selects between 5V or 12V input. The DC/DC converter topology means current draw is less on the 12V supply. For example: If your USB device draws 500mA, USB bridge A will only draw about 220mA from 12V.


USB bridge A is compatible with all Class Compliant devices. It also supports some gear that is not quite Class compliant.
Rule of thump: If your device does not need a special driver in Windows, Linux or OSX, it will work.
So far it has been tested with the following gear:


  • Korg Nanokontrol 2, Korg Nanokey 2
  • Korg microKEY 37 MkII
  • AKAI Professional LPK 25
  • Alesis Q49


  • Korg SQ-1
  • Novation Launchpad Mini MK2
  • Novation Peak


  • Roland UM1-G
  • Thomann Midi USB 1×1
  • RME Fireface UFX

Technical specs

  • Printed aluminum front panel, 2mm thickness
  • Voltage supply 12V or 5V
  • Includes 12 to 5V converter
  • Supply current: +12V: ??mA , -12V: 0mA, 5V: ??mA + current drawn by USB devices
  • USB devices may draw up to 500mA current each
  • Dimensions: 3HE, 2HP, 128.5mm x 10mm, Depth: < ??mm
  • Weight: 30g

Buy USB Bridge A

Tubbutec Webshop, Worldwide Schneidersladen, DE – Test it in their showroom! Perfect Circuit Audio, US Signal Sounds, UK