The firmware on this page is for fully assembled amp. It will not work in Hardrock-50 amplifiers that were sold in kit form. If you aren't sure if you amp is a kit, turn the amp on and watch the screen. If it says HW: J this firmware is for you, if not loading this software will brick the amp.
3/3/26 - Version 5.1a updated to allow ATU to be used with the amp.
The the firmware update instructions are in the Operating Manual.