Don't know how much this will help you since most of my gear is of fairly old vintage. I have a SS Mark Levinson ML-1 preamp controlling a rebuilt Mac 240 tube amp driving a pair of mid seventies Klipschorns. The sound is very clean and dynamic and I love looking at the tubes glowing at night, kind of like watching a fire on a cold winter night. Macs have always been known for their excellent output transformers. If you are buying new, maybe you could borrow a 275 from a dealer to see how you like it.