I presently own a 230v NAD C370 & NAD C521i with Axiom M60ti speakers. I'd like to bi-amp my system, but can no longer source a 230v NAD C270 power amp. I can, however, easily acquire a 110v C270 through a US dealer. As my house is wired 110v/220v throughout, I was wondering if I could simply power the two amps with their respective voltages in bi-amp mode or will the difference in voltage/hertz make such a set-up unworkable?