Waiit... what? Was that your pre-April fool's day joke? Any specific tubes you're referring to? I'd say let's treat his statement as a hypothesis until proven otherwise, because it's the logical scientific method to verify something before making a claim.
What I was basically saying is that when using an adapter such as 6SN7 to ECC88, all of the 9-pin miniature tubes will be compatible as drivers on the Elise, such as 12AX7, 6DJ8 and all 12A
_7 class, as these are the exact same pinout, minus small different Mu and Gain factors. The aforementioned are guaranteed to work, as long as the tube isn't defective. The other tubes listed on the compatibility chart should be compatible too, though some may / may not require the same adapter.
Here's my favorite setup ever so far - for analogue-era recordings at least:
And a close-up of the beautiful orange glowing pillars of these 6AS7G's: