I just rolled an RCA JAN CRC-5R4GY into my WA6, and I am very impressed. I'm not sure if this is the highly sought after WWII version that some say compares to the Westinghouse 274B, but it has the double-d bottom getters and looks exactly like pictures of the WWII version I have seen. At any rate, it has a lush tone that matches up well with my Grados. It also manages to provide a lot of detail, strong bass and an excellent soundstage. I've rolled a lot of good rectifiers through this amp--Mullard and Matsu****a 5AR4s, RCA 5V4G, Valve Art 274B (a great buy)--and this could be my favorite. There hasn't been a lot of discussion about this tube. I wondering if anyone else is using it and what your thoughts were. How did you like over the long term? What do you like about it? What driver tubes match up best? As always thanks for the help.