Cryogenic treatment of tubes? Anyone with experience positive or negative?

Generally speaking, almost all materials benefit from Cryo, not only steel and aluminum tools because they become harder, less brittle, stiffer, more durable, don’t ring as much, etc. Many audio items benefit from Cryo for the same or other reasons, glass, metal, plastics, tonearms, cables, capacitors, resistors, CDs, records, etc. etc.

I have never heard any difference, when comparing from the same batch lot.

But I seen/heard from a few customers now their tubes got noisy or flared and died after cryo’ing.
If you guys think about it Cro’ing your precious tubes is great way to make them unreliable.
The glass tube envelope vs the palstic/bakelite base v metal pins, will all expand and contract at different rates when cryo’ed.
Therefore having a great chance of unsealing the glue bond between the three and the tube loosing all or part of it’s vacuum.

Cheers George

@georgehifi  My experience with the tubes mentioned above is just the opposite of what you posit.  I've had replacement tubes waiting in the wings for some time, expecting that my tubes would be getting noisy by now and would need to be replaced.  Not so.  They were quiet from the get-go and remain so.

Where I had trouble was with NOS tubes which got noisy so quickly that buying more of them after several tries just didn't make sense to me.  As always YMMV.

I cryo’d a brace of matched Sylvania Badboys and a Tung Sol 1942 Rectifier. Post Cryo with nominal one week rest period they all sounded great, no problems. Faint heart neer won fair maiden.