[SteveFord]

I'm curious, could someone please explain the reasoning behind cryogenics when it comes to tubes?  Is there any real value this, either sonically or perhaps in extending the tube's lifespan?
I can see packing Walt Disney on ice but tubes?

[JakeJ]

Do your homework.  Google is your friend.  There is a plethora of information about cryogenics and its benefits on the web.

[JohnR]

Finding any that isn't from a vendor is not that easy.

Thing is - tubes get hot. Doesn't this "undo" whatever cryo treatment does?

[Ericus Rex]

Finding any that isn't from a vendor is not that easy.

Thing is - tubes get hot. Doesn't this "undo" whatever cryo treatment does?

Exactly my skepticism on the subject.  There is no doubt the structure of the metals within a tube change at low temps but then the tube's cathode is operated around 1100 deg/C which would surely UN-temper that new crystal structure.  I suspect that A/B-ing a cryo'd tube to a non cryo'd tube after 10 hours of operation would be inconclusive.

[kevin360]

In my opinion, it's better to obtain the tubes that were designed and constructed to deliver the qualities the cryo treatment purportedly renders. Then, I can hear my father saying, "Son, there's no point polishing a turd; you'll just end up with a shiny turd."

Some of the 'science' I read in association with this hobby smacks of 'pseudo' to me.

I don't necessarily mean that as a judgment on the topic at hand. It's more a general observation, but I confess my skepticism about this.

[JakeJ]

Not all info is from commercial websites, but I agree much hype is out there.  Lots of shiny turds are available at multiple price points. 

http://en.wikipedia.org/wiki/Cryogenic_treatment
http://en.wikipedia.org/wiki/Cryogenic_hardening
http://cryogenics.nist.gov/

Off the top of my head I imagine cryo'd tubes may benefit from reduced or eliminated microphonics.  Or maybe the opposite is the result.

Perhaps the better question would be has anyone compared cryo to non-cryo tubes and can they post their experiences?

[Devil Doc]

Well, I had the tubes of my rifles and shotguns cryoed and they sure are a lot easier to clean.

Doc

[JakeJ]

Then I should have my colon cryo'd so it will be easier to clean.  Hmm...I'll have to ask my proctologist about that.   

[SteveFord]

Sorry, I should have made it clearer: does anyone on this site, who does not have any sort of an agenda, have any actual experience with cryo'd tubes? 
I'm skeptical but am always willing to be proven wrong. 

[jtwrace]

Sorry, I should have made it clearer: does anyone on this site, who does not have any sort of an agenda, have any actual experience with cryo'd tubes? 
I'm skeptical but am always willing to be proven wrong.

I cryo all of my tubes, wires and I even did my SSD.  I do it mainly based on what I know works for auto parts and it's pretty much free.  Do I think I hear an audible change?  Yeah.  Do I think I could do a DBT wtih success?  Heck no. 

[galyons]

Sorry, I should have made it clearer: does anyone on this site, who does not have any sort of an agenda, have any actual experience with cryo'd tubes? 
I'm skeptical but am always willing to be proven wrong.

I tried some new stock cryo'd small signal tubes, MM phono stage,  versus same brand not cryo'd.  Subtle improvement, but not enough to make me change out my OS tubes or cryo them.

[Quiet Earth]

Steve,

I haven't had the opportunity to do a before and after test, but I do have two sets of cryo'd 6sn7s that started their life sounding pretty good and then got harsh/brittle/aggravating on me after several hundred hours. This is a totally subjective comment, I know, but that's all that I can contribute at this time. One of those cryo'd 6sn7s became way micro-phonic on me, but there is no evidence to support that the cryo treatment was the root cause of that problem.

For now I just have a gut feel that cryo treatment for tubes is not a good idea. If someone offered to cryo my tubes for free I would decline.

[thorman]

I am by no means an expert,but have tried Cryo'd tube types EL34,12ax7,12at7,5751,12bh7a,6201 and probably a few I forgot..My best explanation might be,I no longer use "any" Cryogenic tubes..No consistancy whatsoever ( my Opinion only )...Very minor improvement in some tubes and worse sonics in others..The only good things is with cheap new production tubes,many don't survive the process and you get the strongest of the batch that did survive..For me its just a way to spend more money for nothing........

[jtwrace]

Interesting that two people have had issues.  I've NEVER had a problem with anything including a whole dac that I did once.  It's very important to use a "real" Cryo house.  Many places use what looks like a freezer that is rectangular.  It's very important that the top and bottom in the entire unit is the same temperature.  Many are not this way! Also, ramp times are extremely important.

[Quiet Earth]

   I just remembered that I also have two  Tungsol 12AX7s with the Cryoset sticker on them. They are sitting in the bone pile now. They only worked for a few weeks before they failed completely. I guessed they survived the special process just long enough for me to finish them off. Or maybe its because they are new production Tungsols and that is why. Who knows? 

[Ericus Rex]

I'm sure Cryogenic treatments work just fine for low-heat applications like cables and even entire dacs (I'm not trying that one though!) but for tubes the 'improvement' would only be temporary, IMO.

[jtwrace]

I'm sure Cryogenic treatments work just fine for low-heat applications

That's actually incorrect.  It's mainly used on very high temperture items.  I use it on items that are 1500*F and above as well as items that work in the 150*F range. 

[Quiet Earth]

Room temp is very hot compared to cryo temp, so warming it up to remove the cryo effect would be true for all applications.

I think . . . 

[Ericus Rex]

I forget the actual numbers but most metals begin tempering (softening) at just a few hundred degrees (350 deg sticks in my head, for some reason).  Cryo-crystalline restructuring would probably hold until you reached (and then exceeded) that temp.  True, room temp is much higher than cryo temp but you're still way below tempering temperature.

What high temp items are cryogenetics usually used on, jtwrace?  Are these items glass and metal?

[Scott F.]

You skeptics need to read these links. They hold a plethora of information on the effects of cryotreatments. None of these links have anything to do with audio. These are providers that give independant analysis of the scientific facts behind the process. Most of what I provided are speaking of manufacturing but the process absolutely applies to audio.

Here is a quick cut and paste from one of the sites;

•     Increase resistance to abrasive wear
      Requires only one permanent treatment
      Changes the entire grain structure of the metal, not just the surfaces
      Refinishing or regrinds do not affect permanent improvements
      Eliminates thermal shock through a dry, computer controlled process
      Transforms most retained austenite to hard martensite
      Forms micro-fine carbide fillers to enhance carbide structures
      Increases durability and wear life
      Decreases residual stresses in tool steels
      Decreases brittleness
      Increases tensile strength, toughness and stability
      Relaxes internal stresses
      Works on new or used tools
      Reduced down time, less maintenance and higher productivity
      Deep cryo processing is compatible with other treatments (TiN, Chrome, Teflon etc.)
      High alloy steel cutting tools stay sharper longer, fewer micro-cracks, less chipping
      Results in the orderly arrangement of crystals, increases internal bonding energy, and achieves a structural balance throughout the mass of the material
  
  The grain structure changes in cryo treated materials were very significant.
  Results of microanalysis were:
  
      50%-75% decrease in grain size in treated specimens
      Much more uniform distribution of carbon
      Alleviation of grain boundaries
  

Here are a few links for your reading pleasure. The first one is hardcore science that proves cryotreatments work (from a metallurgy standpoint)

http://www.nitrofreeze.com/eta_carbide.html

more

http://www.nitrofreeze.com/toolsteels.html

cryo for the automotive industry

http://www.sigmaautomotive.com/cryogenics/portal.php

an article stating that NASA and space exploration were the first to notice the effects of cryotreatments

http://machinedesign.com/article/cryogenic-tool-conditioning-extends-useful-life-0730



Now, I could go on and on with links but I won't. Cryotreatments show benefits for nearly everything they have been tried on, from cutter heads to gears to brakes and rotors to baseball bats to golf balls and clubs.

Let's forget about the audible effects for a minute. When you think about what breaks down in the tube it is the filament (unless you loose the vacuum). The filament is made of metal, right? Yep, thoriated tungston or nickel coated with a mixture of barium and strontium oxides. Given these are all metals, it stands to reason that the cryo effect will take place within a vacuum tube. The atoms will (slightly) reorganize, grain boundaries will be alleviated and grain size will reduce. As a direct byproduct, you will get a direct increase in metal life. All good things.

Taking this boundary and grain rearrangement of the metal one step further, it stands to reason that you just might hear a difference between a treated tube and one that isn't. Whether you hear it is entirely up to your ears, system and ability to part with $25 bucks to experiment.

Oh, cryotreatment does not wear off when heat is applied. If it did, they wouldn't keep treating copper welding electrodes for heavy industry.