naww, don't be afraid. I've been placed right on top of a nice old Neumann U47 before, and no one blinked an eye about "sensitivity." Most microphones are made to handle vocals at moderate to loud volumes, unless you are blessed with an extrememly loud voice, it's gonna be tough to overload it singing close. right on top of the mic is not an uncommon technique for a really big sound, esp if the singer has a quiet voice... or in radio, you see it all the time. At the very least, it's not going to hurt you (or the mic) to try different distances, record the results, and compare for yourself... that's ALWAYS going to give you better results than using an arbitrary set of figures for "recording distance" that someone else tells you. Of course, if you're closer than say 10 inches you probably need a pop filter.