Hi, I'm korean bassist, I have avalon u5. but this avalon is 110v. just i knew. but, i checked to my avalon u5. i saw 230v switch inside my avalon u5. but i heard that change to pusebox, too. I can't found avalon u5 manual. on avalon design website, i found 2page manual. how can i chaged to my avalon u5 to 220v?