The Mastermind GT/22 has secondary MIDI ports that use 6-pin XLR connectors. These function exactly the same as the 7-pin MIDI ports, but use a more durable connector that locks. You can purchase these cables from Best-tronics (www.btpa.com), but if you'd like to make them yourself, two diagrams are attached. Please note that the MIDI input on the GT/22 is an XLR6 female, and the MIDI output is an XLR6 male connector.
Please note that if you're making a long cable (25 feet / 7.5m or more) and you're planning to use it to provide phantom power, we recommend using two wires to connect each phantom power pin from end to end. This helps to minimize voltage drop down the length of the cable. The phantom power pins are pins 1 and 2 on an XLR connector and pins 6 and 7 on a DIN connector.
NOTE: These cables will also work with the front panel XLR connector on an Effect Gizmo or Rack Gizmo.