I should have mentioned that I'm using the 5670/6DJ8 tube socket adapter available on-line. It did not require any circuit modifications.
Also, now that I'm a couple of hours in, and listening to some orchestral music, the new tube continues to provide a more fully fleshed out timbre. I'd describe it as the note fundamentals are fuller and a tiny bit more realistic, though I don't know how that is possible.
Also, now that I'm a couple of hours in, and listening to some orchestral music, the new tube continues to provide a more fully fleshed out timbre. I'd describe it as the note fundamentals are fuller and a tiny bit more realistic, though I don't know how that is possible.