OK amp guru's I need some help and am an electrical moron. I just got old marshalls that ran on 240v. I now have a step up regulator that puts out 220v+-4%. I measured the output at 218 to 222 volts. I was told to continue to run these at 240v and that they actually sound best at 240v. Is the 220v step up adequate? Should I keep the tap at 240v? will running at 220v in the 240v tap create a problem? There is a 220/210 v tap on the amp? Should I use that? I really don't want to blow any transformers. Thanks for your help.