Frank, so I've fallen into the trap of buying up various flavors of 12AT7, 6201, E81CC, etc to try in my Ultra. I also have a tube tester (no sense going into this blindly

). I happened upon a pair of Siemens ECC81 triple micas that test nice and strong... but...
The triode sections on one of the tubes is within 2% of each other, while the sections on the second tube is within 10%. My question is whether the FetValve can compensate (when rebiased of course) for this kind of tube difference between sections. My current tubes happen to both have matching triode sections that are well within 2% of each other. I've been wondering if that sort of close matching allows for the FetValve to just sort of... operate better?