[TenTec] Centaur Tubes odd ones in parallel

[km2km at twc.com]

Ok, guys, here is the scoop.  

My trusty Centaur seldom needs to be re-tubed, BUT now I have two pairs of tubes,  one pair Taylor, and the other pair Svetlana because over time one tube left the troika for the electronic dump.   Yes, matched tubes are the ideal, but having a couple of pairs sitting around doing nothing for me and no foreseeable makes me wonder.  Just what would happen if they were a mixed troika.  That would leave one tube in the bin ready for another time.

Any ideas on dire consequences?

Many thanks,

Kris KM2KM 
MERSCHROD
123 Warren Road
Ithaca, NY 14850