the voltage problem is easy to deal with. just buy a voltage converter. they are like 12 euros in germany, so I guess they're around that price in the uk too. I bought all my mixers are from the us and always used voltage converters. never had a problem, no matter if it's internal or external power supplies. for the rc 20, I just used the power supply of my old monitor speakers. the only things that matter are the plug obviously and the Ampere. if the voltage is higher, it doesn't matter. you might have to reverse the polarity on the power supply but that's easy to do.