I've tried 3 or 4 diff. sets of cryoed tubes in the past and also after very careful comparison I really couldn't tell any difference either.One set of Mullard reissue el34 went fuzzy and noisy in a 2 month period and one tube went completely bad.
Maybe other people have had better experiences with cryoed tubes but I would'nt recommend them.
The idea of Cryo'ing the tubes is to relax the metal parts to allow the shapes to settle sort of it also improves the electrical properties including less electrical resistance . similarly NOS tubes that have been sitting for a long time don't need this because they have naturally relaxed over time. if the parts were already from old metal let say then you wont get as good of a change with the treatment. Some metals react differently as well so you get various results. if its cheep then its worth it, if done right, if not done right it can actually damage the tube and reduce the life of the tube. best way is to stick the tubes on a shelf for 50 years, oh that's NOS.
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.
@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 thought the same as George. Maybe I’ll cryo what’s left of my stash of 6sn7s with my head, should I fail to outlive them. Can’t imagine what NOS/vintage tubes will cost whenever medical technology allows for re-animation. Although one might wonder whether it will be a world worth waking up to by then, if it actually happens, or whether there’d actually be a market for tubes...audiofolk may be extinct by then.
Here is an electronic engineers perspective on Cryo'ing Tubes.
Effect on Vacuum Tubes?
Don’t knock these electronic engineers they designed everything your listening to, without them you’d have nothing but voodoo/Geoff to listen to.
Georgie old boy, this is simply a case where experience and education Trump someone’s opinion. That someone being your electronics engineer. Let me explain. Electronic engineers don’t get any courses in Materials Science, Engineering Science and Strength of Materials as do Aerospace Engineers and he obviously has zero experience in cryogenics whereas I have 20 years of experience. Therefore his opinion is irrelevant. Your use of his opinion is actually an excellent example of Appeal to Authority. For that you get a gold star.
I am aware of at least 2 speaker manufacturers in the past and present that cryo(ed) the internal components/wires of their speakers. I can't imagine it is based on anything other than perceived improvement or possibly for the reason given by Glennewdick. His explanation is my understanding of the overiding benefit aside from having no benefit to NOS tubes, 1st time I heard that. I would say that sonically I have THOUGHT I heard differences, output tubes in an amplifier years back, this would have to be revisited before I decide. My understanding that there are different methods and that not all cryo treatment is the same. Someone else with more experience might chime in on that point?
I am aware of at least 2 speaker manufacturers in the past and present that cryo(ed) the internal components/wires of their speakers. I can’t imagine it is based on anything other than perceived improvement or possibly for the reason given by Glennewdick. His explanation is my understanding of the overiding benefit aside from having no benefit to NOS tubes, 1st time I heard that. I would say that sonically I have THOUGHT I heard differences, output tubes in an amplifier years back, this would have to be revisited before I decide. My understanding that there are different methods and that not all cryo treatment is the same. Someone else with more experience might chime in on that point?
>>>>>Right. Not to mention high end electronics manufacturers who Cryo their components, e.g. Meitner, and most high end cable manufacturers, and many aftermarket fuses manufacturers who also routinely Cryo their products. I’m pretty sure Cryo Tube or some such company sells cryo’d tubes. Walker Audio used to Cryo tonearm and other parts for their $100,000 turntable, dunno if they still do. Hel-loo!