The transformer is rated at 240v, but I'd use 230v if 50hz...this will make the transformers quieter.
Thanks Dusty, I've been checking my mains voltage over the week and it varies at times from 225V to 245V. The hum is hardly an issue now but when it does show itself I noticed that the needle on my multimeter doesn't decrease/increase.
The reason I'm considering a power re-generator is because I notice my system sounds better at some times than at others, this was also the case when I owned the Cary tubed amps.