What amp did you use with the Beacon, Ed? Is the output impedance still relatively high, several thousand ohms? That was a couple years ago talking on AC about Beacon 1.
I think that the old iron that Blair uses is his secret ingredient. A great tube amp has to have great output transformers. That vintage "tube sound" comes largely from transformers intended for mass market tube gear, be it new or old. One listen to OTL (with appropriate load) shows that it's not the tubes making the warm glow. I think we have similar taste in tube amps Bunky. Can't wait to hear how you like the Niteshade.