I have the manual too.. But I'm not sure how to run at 4ohms? I just got a Aquilar GS212 600w 4ohm cab and ran it at a show last night. I had the head pretty much maxxed out. I just plugged the cab to the head, so I'm assuming it was at the 8ohm 275W setting. As I have the cab for 30 days before I cannot return, I want to see what running at 4 ohms is like. I want headroom! So, at the risk of sounding stupid, how does one run the SVT3 pro at 4ohms?