Tube Shelf Life

I've been told that tubes don't deteriorate (if unused) over time....

They should be fine.

Believe it or not tube shelf life can be as high as 100 years...that is not a typo! I would keep them in their original boxes, in a cool place where they are not subjected to possible bumping, banging, or droping. The 'silver cap' inside the top of the tube is a substance called 'getta' which is designed to capture and hold stray atoms of Oxygen, Nitrogen, etc., which may effect the performance of the electronics. If the silver turns to powder and flakes off your tube might have sprung a leak! I my opinion tube design was discarded premature...I don't believe the engineers fully exploited possible designs.

What can go wrong with something sealed in a glass tube?
The pins may corrode over enough decades but that is easy to fix.
For cool tube reading, try www.sonicfrontiers.com and be ready to read loads on the history of tubes.

If your old tubes start passing gas, believe me, you'll know it if you're in the same room. Just keep them away from the dried fruit and legumes and you'll be fine.

Marco