OK to replace one power tube for amp?


I have Joule Stargate Monos that use the Russian 6C33C-B power tube, two per amp. One of them isn't holding bias very well... wandering a bit. Can I just replace the one tube? Each power tube is individually biased in this amp and I've heard that matching pairs with 6C33s is just not something that happens so it would seem ok to buy 1 but I didn't know if having tubes of different ages was bad.
dhcod

Showing 2 responses by swampwalker

Should not be a problem since they are individually biased. One question; when you say bias wanders a bit, how much are we talking about?
How do I know whether the 6C33s are good? Well, if they are 13 years old, I think that they don't owe you anything.