I rebuilt the power supply section on 1of these i am amp repair tech and mine was pushing 5,550 at .5 and it didnt struggle need to supply atleast 14 volts and can stay steady at 700 amps. I also done many other brands if thus same board and the ground zero along with the crescendo and dc audio look alikes all performed about the same but the ground zero was a bit touchy on the output side.

Oh damn, I hate it when the amps don't survive the resistive load test. The power was jumpy as well.