After looking at the schematic I saw there is an error in the MIDI jacks.
The GND (pin 2) of the MIDI in schould be not connected. On the NAVA it is connected to GND.
Here are the specs from MIDI.org

Please check again with your MM. Pin2 of the MIDI In Din connector is NOT connected to the Groundcomboy wrote:While updating the firmware I realized a classic USB GND loop sound when I hooked up the nava to an usb midi interface.
After looking at the schematic I saw there is an error in the MIDI jacks.
The GND (pin 2) of the MIDI in schould be not connected. On the NAVA it is connected to GND.
Here are the specs from MIDI.org