My GK MB Fusion 500 showed up today. I haven't had a chance to do anything but hook it up to the Ampeg SVT-212AV. Tomorrow should be a good day to power that Little Monster up! I like it being a 4 ohm, 500 watt head, to match up with the Ampeg SVT-212AV, being a 4 ohm, 600 watt cab.