Hi All,
Stumbled across this thread, as I had brought a second hand HM8030-3 a while back and finally had a use for it (Tube amp) and I realised it was completely out of calibration. Based on the post from coromonadalix, I was able to figure out how to adjust it. While it's 5years later, does anyone still need to know? As I found it was pretty frustrating that I could fine no information on calibrating this model.