Tubes for my Aesthetix Calypso

Now that I know where to go for good quality NOS tubes for my Rhea........I probably will replace the 2 tubes (per side) in my Calypso. The question is for Calypso owners.....there is a 12ax7 and a 6922 per side. In addition to calling Aesthetix to find out what they say, what tube is the "more important" one to replace.
Thank you for your help and advice!

Rick (RWD)