Where can I get a copy of the Mustang GT v2.0 Manual Addendum? You can view and download the v2.0 Manual Addendum right here! Related articles Where can I get the expanded manual for the Mustang GT amplifier? Mustang GT Firmware Version Release Notes Where can I get a copy of the Rumble Stage/Studio v2.0 Manual Addendum? Are there foreign-language translations of the Mustang GT Expanded Owner’s Manual? How do I update the firmware on a Mustang GT or Rumble digital amplifier?