Thanks Myles. I was surprised at the EH12AX7. I use them, but haven't bought any in a few years.
They can be one of the best. In a slightly different package, perhaps more selected, they are sold as the Tung Sol Reissue. Somewhere I once posted a photo where Dan Boul at 65 Amps held one of them up next to an original. Actually, it was probably on one of his weekly webcasts. I pointed out the differences. Nothing similar in design or plate size at all but the TSRI is usually the best of the EH variants.