Enjoyed rereading this thread. Getting into 2A3 sound myself. Not building mine. I have to wait a year for handmade headphone amp. It does have a driver and an input tube. So far I have 2 pair of RCA 2A3s and one pair of Sylvania 2A3s on order from Italy. Two RCA 5U4G rectifiers and a Sylvania one and two U52 rectifiers. For input tubes I have two Super Cyro 6N1P-EV Voshod and as a substitute, 6Bq7As by RCA, Sylvania and Raytheon/Japan. I think I am done buying NOS. Present manufactured 2A3s are supposed to be superior. How come you haven't tried any Asian 2A3s?? EML and Sophia are supposed to be good too.