Various comments have been made about the different 12BH7 tubes. Jim McShane likes RCA's. In particular the long black plate. A lot of folks concurr with this. The Tung Sol black plates are also highly regarded.  "The EI version lacks the detail of the RCA." "The GE is edgy." To quote various posts over on Audio Asylum.

If you are turgid to try a 12BH7 make it an RCA or Tung Sol black plate 12BH7A.

Yesterday I discovered I had a GE 12BH7 tube sitting on a shelf and can't remember where I got it from.  Put it in the ZBOX before I went off to work. . . came home and turned on the stereo and wow it sounded good. Tonight after work again it is sounding great. I think th 12BH7 tube type may be just what Top Ace is looking for. I have been using 12AU7s from GE for a while both before and after I sent the ZBOX back for repair. The 12BH7 is a bit less warm, but gives a very solid image rooted in space.  Right now I'm listening to a George Benson solo and it sounds like it's coming from a guitar amp in the room. There ARE two in the room actually, my 1959 Bassman LTD Reissue, and my Epiphone Valve Jr.

I notice Riviera Ranch says he's seen comments that the GEs are "edgy." Well, this one sure isn't, very sweet and passes on the ambient information well. I find that a tube sounds different in different circuits. I'm sure in some this tube might sound "edgy" but it sure doesn't in the ZBOX.