Got my first SET amp. Its an ASL MGSI15DT bought over at Audiogon. 15W tetrode/5W triode both single ended. Still getting used the new sound. It certainly sounds different from my CJ MV-55. The highs are more rolled off and the bass is not that taut but ooooohhhh that midrange. The vocals sound chesty and full of life. I can hear the singers breathing almost like hearing their emotions. The amp has a minimal 4db NFB so my next step is to remove all feedback and see how it sounds.. Have ordered some Jupiter beeswax paper coupling caps for the next upgrade. Can't wait to open up the amp and start playing with my saudering iron. Just wanted to share my new found joy toy.