I recently sold my TAD 60. For power I had run Svetlana EL34s, SED Wing C EL34s, Valve Art KT88's, and Shuguang KT100's. All were very good except for the Svetlanas which are merely average. I was running Raytheon 5814's (to the best of my recollection) and JJ ECC83 for driver/pi.