For those that are interested, I’ve been doing a little rectifier rolling. There are definite changes in the sound of the Cornet, on the same scale as changes I have experienced with different signal tubes. There’s a lot of interplay between the signal/rectifier tube choices, so I can’t provide a recommendation. But I will briefly note below the differences I hear in my system using the same AX and AU signal tubes.
5Y3 GT Sylvania vs 5Y3 GT RCA. The RCA is more “open”, a little livelier and a tad brighter. Between these 2, I prefer the more open presentation of the RCA.
5Y3 WGTB GE 5-Star (6087, indirectly heated) vs 5V4G Sylvania. The 5Y3 is somewhat richer and fuller than the 5V4 (more midrange emphasis). The 5V4 is a little brighter, seemingly more dynamic and has a touch less bass volume but the bass is deep, tight, more defined (less flabby). I like the sound of both and haven’t decided which I prefer. I think it would depend on the AX and AU choice but I haven’t played with the signal/rectifier combination.
On an appearance scale, the 5V4G is way cool looking, the 5Y3WGTB is cool looking and the others are pedestrian.
I ran across the 5V4G going for just a few dollars (NOS) and decided to try it out, not wanting to pay a premium for a GZ 32 or 34. So far, it works. The 5Y3 WGTB is also very nice. The trusty, durable, and reliable 270BX transformer that we all know and love may run a couple of degrees warmer with the 5V4G.