cryod tube vs non-cryod tube

There seems to be pretty good evidence that cryo treating tubes change their sound. I've heard tubes that were improved and some that were absolutely made worse.

Cryo treating new production tubes is not much risk money wise, but I would be hesitant to treat rare, expensive NOS tubes such as Telefunken or Siemens 9 pin design.

Good that Thorman got positive results.

If anyone has cryo treated NOS Euro tubes (like Tele's), I would love to know the results. If possible, discuss the equipment that benefited and test conditions. In my opinion, the best possible world would begin with a matched quad, thoroughly listening to each pair before and after cryo treatment.

I guess from what i am seeing a lot is some sellars are cryo-ing " new production tubes" where there isn't that much risk ( as Albert mentioned ) to either party involved. For me buying a cryo quad of el34 SED at $150 -$175 a quad is better than 300-500 quad of nos el34 tubes. Being the Cryo quad to me is/was better it was worth the risk. I also think ( as mentioned ) not all tubes sound better cryo'd ,and thats why you see sellers carrying only certain brands and types to be cryo'd and logocilly ( i hope ) the ones being cryo'd should be the tubes that work well with the process...

one would be a lot colder than the other....

does it help microphonics?,like a 7044 tube. what do they usually charge to cryo a tube?

Diamonddude18 : I can't say to be sure but my guess is these tubes would/should be checked for noise etc. after the cryo process,and do to the expense of the process I would assume ( again )theres probably a failure rate on some tubes that don't make it thru the process. A while back I had checked on the price ,if you were to send lets say a quad to have cryo'd.The cost was $10-$12 per tube.That may or may not be true now. My El34 SED can be purchased online for $75 ) aprox ) a quad. I paid $150 cryo'd ( price is with new tubes )...These are Pearl Cryo's.They were purchased at The tube depot..They have many other cryo'd tubes available. Nice people to deal with too.