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

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.

Kenny.

I have a Cryoset pair of Tungsol reissue 12ax7 that got a bit noisy after a month of use.  A standard pair was supplied with my Jolida amp and there seems to be no difference between them other than the standard pair did not get noisy.

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.

Not wanting to be the contrarian here but I have had very good results with Gold Lion 12 AU7s from Cryoset.  The pair in my linestage just stay quiet!  I have two more of the same in boxes in the stereo room closet waiting...

I too have the Gold Lion 12ax7 gold plated pins and Cryo treated that I use for my line stage, very quiet and very detailed sound. I highly recommend it.