I'm running and Ampeg SVT-IV head though two Carvin RL2X10 cabs. They are rated at 4 1/2 ohms and 400watts each. The Ampeg is rated 490 watts RMS @ 4ohms per side. My Ampeg has blown both sides of its power section on 2 different occasions. Both times the repair tech bench tested for over a day and it ran great for months then came unbiased and blew. Now its blown again and I'm debating just buying another one. But I want to avoid the problem in the future so...... Could the 4 1/2 ohm loads on each side be causing the power sections to wear and blow. I run at high volume usually but haven't notices any other problems. Any ideas?