Ok, I'm an endorser for these guys, but I know that they treat all of their customers the same. Anyways, I'm one of their whinier customers. (never give an endorsement to a gear freak) I'm in Poland right now and took the new Doubler with me. As I'm not sure of the ability (paranoid) to switch voltages on the amp I have a voltage transformer on our rider. I get to the gig (nicest jazz club in Poland) and the transformers they got are adequate for an electric shaver. Won't work for an amp. It's early morning in the states and I call Mike Dimin. He answered and I told him my problem. Within 5 minutes he had talked to the amp designer, called me back, and walked me through changing to 220 volts. You have to remove about 5 screws but it's a piece of cake. Funny thing is it seems like there is more power at 220. ( I'm very pleased at the output at 110) Gig went great. Amp sounded great into an Aguilar 4x10. ( I don't care for Aguilar speakers) Love the gear---love the company By the way, Tobiac Pohling (Vector) is meeting me at a gig in Koln, Germany to let me try his new pickup on my Volante. I'll keep y'all posted.