Ruby 6L6 Duet-how do I tell if they will work in a Mesa?

I've got a new unopened pair of Ruby 6L6 tubes that were for another amp since sold and I'd like to know if they would be safe to use in a Mesa. On the label it has:

Ruby 6L6GCMSTR
IMG matched# 13, other tube has 14
PC: 34
TC: 3050

These number mean nothing to me so I hope someone here can decipher this for me.

Should be perfectly safe. I would say that retubing with anything voids the warranty but if the warranty has expired then retubing is a great idea. It really helps get you closer to the tone you want. As far as placing the tubes if you have 4 tubes in your amp you don't need a matched quad. Most amps that have come out in the past 30 years run tubes in pairs so if you are looking to replace 2 in a set of four then find out how they run. In Mesa it's usually inner 2 then outer 2 are matched. If you already know this or only have a 50 watt then ignore me. But it should be safe.

Always remember that anytime you do any electrical work on an amp there is a chance for failure, so do this at your own risk. But nothing about the Ruby's nor the amp's bias should cause damage.

Peace,
Joshua

I spoke with Ruby who said anything in a plate current, PC, from 32-50 should be fine for Mesa. Mesa just told me 34-40. I'll stick with what Mesa says but still these tubes fall into that range.

Mesa's are biased very cold,so if you plug the tubes in and keep an eye on the plates and they dont glow red/orange you will be safe.Not necessarily optimal,tonewise,but safe.