Hey there. a quick qestion for all you electrician types. I love the idae of the PJB briefcase amp. I've always wanted to have something i could take to use with acoustic guitars when a power source wasn't available. However, my bank account's a little small at the moment. I was wondering if there's a way i could supply the correct power to my small 150 watt head (swr electric blue) from some sort of battery setup? The 12 volt battery used with the PBJ would be cool just from the standpoint of weight, although i understand that even is phil's amp the power only lasts for about an hour. Soooooo. What kind of devices are available to transform the power of a battery to the 120 v required by my amp?