NOS Tubes inferior?

6922? Bad luck!
The dutch made Bugle Boys thrash all current production soundly, even given that yes, glass is porus to (mostly) low molecular weight gasses such as hydrogen and helium - fortunately present in low concentrations.

What will realy stuff tubes is being stored in damp conditions, a little water vapour will reck a tube in a few hundred hours of running.
If you go this way buy tested tubes from a buyer with good and extensive feedback.
They will cost you several arms and legs - which I would spend otherwise on upgrades, unless I had LOTS of money, which I sure don't (even though I still spend heaps on hi-fi!).
Just make sure you enjoy the music!

Sugarbrie's advice in his first sentence is right on the money. I have found that well-tested NOS tubes sound vastly superior, and have had a far longer life, in my Jadis equipment, but keep in mind that the stuff I have was made in the late 80s and designed way before that around the then-available Telefunken and MO Valve tubes. A modern piece of electronic equipment is often designed around what's available today, and may well sound excellent with current tubes.

I disagree with the premise, though, that today's tubes are better--I've had too many experiences with new tubes that are supposedly better technology (NOT materials, mind you--that claim cannot be made, in my view) and measure superbly that sounded mediocre and went bad on me in less than 6 months. You have to be careful buying NOS, both in terms of their measurements and their sonic character in your equipment, but at least in my experience they have been worth their cost, both from a sonic and reliability perspective.

If you love the sound of your CJ, stick with the same tubes. CJ isn't cheap but, they are consistent. Many new and NOS tubes are great but will definitely change the sound. Using substitute (7308) will change the sound also.
Good Luck

There is a good chance that you will be dissapointed with NOS tubes if you try only one brand. There is no reliable predictor of how a specific NOS tube is going to sound in your system without trying them out. Hence the term "tube rolling" which is the act of substituting several brands of a tube type in your equipment to find the best sound. This can become very costly depending on the number of brands you try and how exotic or scarce the tube brand is. For example, you could spend upwards of $200 on a matched pair of NOS Amperex 7308 gold pins and there is no surety they will sound good in your system. You can increase your knowledge on the NOS subject by visiting the Vacuum Tube Valley website. They have devoted magazine articles to the 6922 tube and its close relatives such as the 7308 where they test as many as 50 different tube brands and vintages for sound quality, noise, and gain. The good thing is that they include recent vintage tubes in the articles such as the sovteks, the JJ's and the EI's. Again, this is a guide that will get you started but it is likely that the tubes they rate highly will sound somewhat different in your system. That has been my experience. In my opinion, tube rolling should be viewed as a seperate avocation within the audiophile world. You must be patient and expect to get some tubes that go bad shortly after installation no matter how well they measure. If this sounds fun to you, then go for it. Just don't expect to get the right NOS tube the first time around.

Well, I would like to thank all of you for the time taken to address this topic. It has been helpful and insightful. I do believe that this hobby has a real potential for crossing the 'fun' line. It can be thrilling to experiment with components and increase one's awareness regarding the miracle of music. For me, I also need to be aware of that 'line' lurking (and I have yet to know where it is, though I'm better at knowing when I've crossed it) when it isn't fun anymore.

I do appreciate this website for the opportunities to discuss what we are passionate about. Thanks again for all of the input.