Hi dad-(ah,) Charles,
You're not the first to report on liking the Siemens tubes in AVA gear. I think if you scroll back in the AVA forum, you'll find others agree.
Interesting that you found Mullards to be very close to the JJ's..... 'cause in many curcuits the Mullards are quite different.... sorta like heavy syrup vs. purified water...
WEEZ