By shifting over to the "conventional" pin out I tried a pair of 6n6p, which are pretty close electrically but uses the same pin out as the "usual suspects" . So far so good.

But hey why stop there. We already have "dial a milliamp" ( must revue the archives for Colin’s trick current set up) . For bias I have, 3, 1.6 LED’s in series and for now, I just twist 1 or more of them till there Leeds touch to short them out to lower the bias. I am working on a more elegant solution that fits my little board. Maybe an IC socket or a jumper setup.

With this I can try most any twin triode with a 9A pin out, with heaters wired for 6v, 9AJ and more, just check you'r RC30.

this includes the 12a*7 and 6922 clan.
6fq7 anyone?

That’s a lot of tubes…John