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


I just ordered a matched pair of 12au7 mullard NOS tubes for my primaluna amp. Ordered them from upscale audio.  They offered the cryo treatment, so for only 8 bucks more, I got it.

wondering if anyone has done enough listening to have an opinion on the sonic benefits, or the technical reason why it makes (or does not make) a difference.
meiatflask
I bought 2 pairs of Mullard NOS 12au7 (CV4003), one set cryoed and the other pair not cryoed.  I will be dammed if I could tell a difference.  Incidentally, one of the cryoed tubes started making noise right after the 90 day return policy ended.  I too got them from Upscale.
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.