audio research ref 1/ ls-25 tube question newbie

how critical is "exact" tube matching in the audio research ref 1/ ls-25 pre amps ?

the ref 1 takes 8-6922's, and the ls-25 take 6-6922's... do they have to be dead spot on matched ?
The ls25 takes 4 6922's, I bought a matched quad of EH from tube depot for my LS 25..cost was 30.00 more for the quad. Prefered them to the sovteks that were already there, they seemed less noisy with a blacker background.
No, not at all, any 6922 will work. Having said that; high end audio is all about incremental improvements. The closer they are matched the better the gear sounds.