EAR Phono Classic / Phonobox tube rolling w/ 12AX7As


I've just purchased a pair of vintage 60s NOS RCA 12AX7A tubes to try in my phono pre. Mine is the MM only version w/o volume control and is fed from a Bob's Devices Sky 20 SUT. I'm wondering if anyone has tried 12AX7As in their EAR Phonobox / Phono Classic? If so did you find that V1,2&3 all need to have a high quality tube or is it more important in just 1 or 2 of the positions?
shawnwes