I amp getting my first stack and i am trying to make sure that i wont overpower speakers or anything. Firstly i am getting the Hartke 3500 with the transporter 4x10 cab. the cab is 300W at 8 ohms and the head is 350W at 4 ohms and 240W at 8 ohms. i want to figure out how (if i need to do anything) to switch the head to operate at 8 ohms since there is not an impedance selector on the back. please help me... p.s. i have been looking around and seeing different power ratings "program" and "continuous" on the same cabs. What do these mean?