Cryo Treatment: does it provide improvements in sound or longevity?

@pindac In thinking back on my reasoning for purchasing the cryo'd tubes, one of the reasons was purported longevity. In my case there was also the benefit of being hand picked and closely matched, whatever the case last time I had these tubes checked and measured on Amplitrex AT1000 tubes measured fine, these estimated somewhere between 500-1000 hours. 

I've only seen cryo treatment of tubes post production, seemed to be a thing back in early 2000's when I purchased mine, don't see that many offerings these days.

Interesting how the OP inquired about Cryotone tubes specifically initially of which I was the first to respond to in this thread then Cryotone was changed to "Cryogenic" and my initial response deleted leaving my subsequent responses out of context. Does the OP or anyone else hear have an in with the Moderators to have their posts edited to suit whatever ulterior motives the OP or their Moderator buddies might have? Seems I've seen this before here! Hmm.

There was another thread about Cryotone tubes. This is not it. I will admit that other thread made me think about the treatment and start this thread.

I think this is the thread you were talking about.

https://forum.audiogon.com/discussions/cryotone-tube-back-order-issue?highlight=Cryotone

@ghdprentice "There was another thread about Cryotone tubes. This is not it. I will admit that other thread made me think about the treatment and start this thread.

 

I think this is the thread you were talking about."

Yeah, I know, start a thread and if you don't like the responses start another one and redirect in a way so that you get the responses you want rather than add a post to the original thread and simply changing the tone. Hence, my confusion and completely irrational post!