Sonic differences between 120V60Hz vs 220V50Hz ?

Are there known sonic differences between running a system
at the US voltage standard and the European standard ?

just curious

I'm running my Levinson 336 on 220. It sounds great! I have not compared it with a US voltage. However if you consult PS Audio, they will tell your that this set up is much quieter and that they sell several of their P-300 and P600s wired this way. The dual differentail hook up makes the soundstage much quieter and blacker.