Originally posted by J Epstein
Bernie, there is also the "Rooskie firecracker" - 6C45Pi.
There are similar to 417a or 8020, like the other high-gm tubes matching is a litttle tricky. I like their sound and they are much more available than 8020 surely. Right now I use them as driver for a 2A3 and as the line stage tube in a transformer-coupled line stage. I am thinking of trying these in a phono stage, and using their low rp to operate my filter network at a nice low impedance.
RF precautions are required for these puppies too, like the others you mention.
The good news is that, so far, no one has been able to kill any of them, despite massively ignored maximum specs. I think if you hit them with a hammer they may break, but maybe not.