Cryo Tube Contraversy

Cryo Tube Controversy – The Chilling Truth

1:30 pm

A number of years ago we started to see more and more about cryo “treatment” of vacuum tubes. We read through all the marketing and tried to figure out how this could improve a vacuum tube. Our reaction was that it really didn’t seem logical that freezing a vacuum tube could improve it. We had concerns that the glass where the pins pass through would become compromised due to different rates of expansion and contraction of glass and metal. As well, it seemed odd that stronger steel could make a tube sound better. But to be thorough, we had carefully tested sets of matched tubes sent out to be treated so we could try it for ourselves. Our plan was to have two sets of tubes that had identical measurements. One set would be cryogenically treated and the other not. Doing this would allow us to do a comparison between the two sets and make the results less subjective.

The tubes were sent to a company that at the time was the premier provider of cryo treatments.  After several weeks they were returned. A visual inspection showed they didn’t appear altered or damaged. After testing we found the measurements were not any better or worse, they remained the same. So far so good. Next was listening time. We set up a blind comparison test by having one person install the tubes but not allow the listeners to see which set was used. Our listening panel was a mix of audiophiles and studio engineers so we were confident subtle improvements would be noticed. Our results were very interesting yet anti-climatic. After several comparisons, we discovered that none of our listeners could hear any difference between the tube sets, let alone an improvement.  No one could tell if or when a set was changed.  If we could not hear an improvement, and we could not measure an improvement, we found it difficult to justify selling these “treated” tubes.

Cryogenic Treated Vacuum Tubes.
Cryogenic Treated Vacuum Tubes.

Since this time our friend Phil Taylor at Effectrode has written about his own thoughts on cyrogenic treatment of audio tubes.  He’s been very kind and allowed us to reprint his article here.

35 Responses

  1. Dan Lilley
    Dan Lilley at |

    Thank you so much for applying some basic scientific procedure to examine this issue. The audio industry, sadly IMO, is rife with misinformation, false claims, conjecture and delusion. Your approach helps to clear the air and I applaud you for it.

    A dedicated tube aficionado and satisfied customer,

    Dan Lilley
    Raleigh, NC

    1. luisranger
      luisranger at |

      I use electro harmonix cryogenical tubes since 2009 i try the same brand tubes without cryogenical tratment and i hear too much diference sonicaly vs regular tubes and my system has the same cryogenically tubes since 2009 i audition my system weekens 4 to 5 hrs tops and i know this year i retube my system but the longevity of this tubes is very evident so tubestore you are wasting your time to discredit a that i see but the high end is bloodout because some many company try to discredit another everything can sale some tweaks and gimmics that i call democracy, but i ask tubestore what in the world is selling tubes in mark up prices example electro harmonix tubes, sovtek, tung sol etc why you try to markdown the prices they will get atractive to back the customers like me and everybody in this industry that’s my own opinion sorry this is the true.

      1. Mike
        Mike at |


      2. BicycleJoe Lo-Fi Sound and Vision
        BicycleJoe Lo-Fi Sound and Vision at |

        Could that be because the tubes selected for the cryogenic treatment are hand selected and measured before they are given the treatment.?

        1. MT
          MT at |

          This is likely the case.

  2. mario
    mario at |

    I’ve been using cryogenic tubes in my hi end audio gear and will never use anything else. Most people’s ears aren’t as sensitive as our eyes so it’s no wonder that people can’t hear the difference. If your transformers, capacitors, speaker cables, etc can’t handle the detail of cryogenic treatment, it’s a waste of money.

    Putting hi end spark plugs in a pinto won’t be the same as putting it into a Ferrarri. My suggestion to the consumer, only buy cryogenic products that offer a money back guarantee. If u don’t hear the difference, send them back….stop trusting blogs and so called reviews that can be biased depending on who it’s written by.

    1. Peter Joseph
      Peter Joseph at |

      I totally agree. I have applied this in auto racing engines,rifle target barrels
      Nasa did not develop it for nothing. In truth it not only tightens the molecular
      Structure the tighter the more efficient the electrons can flow.longer wearing
      As well as more so sonicly true.

    2. Anonymous
      Anonymous at |

      “A Pinto!” What’s that?!? 🙂 You reveal your age.

  3. mario
    mario at |

    PS – I can smell an attempt to “discredit” the competition by his article, sorry, you’ve lost a long time customer. There are so many articles by NASA, the Navy, MIT, etc. regarding the use of cryogenic treatment in sensitive passive sonar/listening devices that anyone can educate themselves.

    read up on the Bybee filters that were originally developed for the Navy and submarine sonar equipment. These filters are cryogenic treated to reduce quantum noise and increase sensitivity.

    1. David
      David at |

      I agree because cryo treatment helps with microphonics and noise which a tube tester cannot test. The hearing test may have been done with guitar amplifiers for all we know. A true test would be with a pair of top of the line Sennheiser headphones and with a tube amp such as the Valhalla tube amp with hi res audio tracks. You can definitely hear the difference between tubes. I would take this article with a grain of salt.

  4. Me
    Me at |

    mario’s imagined feelings were hurt. A little sensitive and defensive I’d say. If he wasn’t aware of the cryo stuff, he probably wouldn’t have heard any noticeable difference either. I doubt he could hear deep down into the sub-atomic natural noise floor. If so, he needs to be wired for sonar. Maybe has a leaky cap in his rumble filter.

  5. Glitch Magnet
    Glitch Magnet at |

    How do I tell if my amp has too much quantum noise? I simply MUST reduce that awful quantum noise in my audio amp!!!

    And, I’ll bet putting high-end spark plugs in a Pinto would be precisely the same as putting them into a Ferrari.

  6. roger fisher
    roger fisher at |

    Being a guitar player sense the late 60s I have had a great deal of experience with tubes. Older old style tubes were better than newer tubes for awhile, but the tube industry has gotten better by leaps & bounds plus manufactures of modern guitar equipment have tweaked there equipment to newer tubes. Now to me old style tubes just sound different not necessarily better. Now sense audiophiles are still using a lot of old style equipment NOS tubes may work better & also there may be some different frequency’s that come through with cryo treated tubes in audio equip but I doubt it. But as for guitar amps, i do not hear any difference. It is easy to be brainwashed by info or because you spent a fortune on something & cannot accept that you spent a lot of money for nothing. If you are happy with you sound be happy with it. No sense in causing strife over it. WAR- “We Are Right”

    1. Anonymous
      Anonymous at |

      Is this Heart’s Roger Fisher??
      If so, I believe everything you say!! Lol

  7. Bill
    Bill at |

    Really? People say they can “hear” a difference in cryo-treated tubes? Maybe if the tubes are manufactured in a cryo-type environment, ie – Blade Runner..”I just do eyes!”, they may perform better and work more effectively for ultra-sensitive equipment like SONAR, or WARP drive engines !! Yes WARP drive – call NASA !!
    For guitar amps – cranked, ain’t no one gonna tell me they hear 847 MHz now when they could not hear it before, or 15.5KHz – wow what have my ears been missing !!!
    Please NOS is about as good as you’re gonna get till they’re gone – then trust these guys to find you the next best thing.
    Hell they live in a tube !!
    Peace – be good to each other folks !!!

  8. Les lammers
    Les lammers at |

    I have used them and don’t notice a difference with new production tubes in audio amps. I have no interest in cryo’ed NOS. No, I’m not deaf. Cryo may work well for knives etc. but I’m not sure about tubes,

  9. audioisbadformyhealth
    audioisbadformyhealth at |

    The findings have nothing to do with mocking a competitor since cryogenically treating tubes is not exclusive to one or a couple of competitors. could offer cryogenically treated tubes if they wanted to, and profit from it as well. It’s great that actually cares enough about its customers to keep what they offer for sale, as honest as possible. There is a huge tube seller out west, that is very well known and respected by many, that now offers cryogenically treated tubes for sale. If cryogenically treated tubes are a scam, then that seller out west is risking their reputation just to get $8.00 more per tube. They don’t just sell tubes, they sell audio equipment as well. So if people find out that cryogenically treating tubes has no positive effect or no effect at all on tubes, that dealer is also risking losing its customer base. So how is it that two legitimate websites( and the one out west) have such a different take on whether cryogenically treating tubes, actually improves their sound? What am I saying???? This is audio. This happens all the time. Silly me.

    1. James Blakely
      James Blakely at |

      Thank you tube store for looking out for your much valued customers!!!

  10. Mike Joyner
    Mike Joyner at |

    I find it amusing the counter arguments and accusations against this blind test from a store/distributor who would only profit or at least broaden its product offerings if such marketing claims held up. Going to the extent of throwing in sonar technology to the argument? Pretty sure any modern sonar sensor is feeding a solid state preamp. Much like saying attributes for a good sensor for photographs are the same for machine vision. Semiconductors do benefit from cooler operating temps. Convoluted thinking.

    Please change that man’s brandy to a good ol Kentucky bourbon… Please

    Want to improve vacuum tube performance for an audiophile? Trying operating the amp with everything cooled right? Last I knew tubes run best hot for guitar tone. Theoretically you could reduce the noise floor by cooling entire circuit. Thermal shot noise in passives, fet leakage or in my specialty, dark current in image sensors benefit from operating in a reduced temperature environment.

  11. David
    David at |

    Telefunken does cryo treat their new line of tubes.

  12. Kevin
    Kevin at |

    Cryotreatment for tubes will have a very slight audible difference inside a HiFi Tube amplifier where subtleties are especially audible at higher frequencies in music listening. In a guitar amp I don’t see any reason to do cryotreatment for tubes other than what some people say about them “lasting longer”, of course I have no idea if that is true, but if you have a collectors NOS tube like a 1960’s Telefunken or a Siemens CCa you might want to do anything to make them last longer. Instead of wondering if cryotreatment makes tubes sound better or -different- (different is usually the case since “better” is subjective in the deliberately euphonic world of tubes) we might want to ask ourselves if cryotreatment really does make them last longer. I don’t have the answer to that.

  13. Jambone
    Jambone at |

    I exclusively use cryo treated tubes in my submarine and spaceship.

  14. Mike G.
    Mike G. at |

    I have 2 sets of EH EL34,s, one set of 8 cryo’d, one set of 8 not. After all the comments, posts,etc., all I can tell you is that to me, the cryo’d set sound clearer,have more detail across the audio spectrum, and have far less noise. They took about 100 hours to get the performance they were capable of, certain tubes, as you know, take longer than others to reach maximum sonics.For $8.00 more per tube, the benefits I hear are worth It, no question. You spend the big bucks on the gear,speakers, cables,etc.,I feel cryo’d tubes provide an audible upgrade for a small price,at least in my system.

    1. Jean
      Jean at |

      EH are graded and sold accordingly,I used to work for a large supplier who graded them,nothing to do with cryogenics,but they’d like you believe there is.The truth is the more you pay the better you get,simple as that.And as for EH…they are fragile,unreliable, try some NOS Siemens and you will not believe your ears,but then again maybe leave them for someone who can hear the difference!

  15. Jim
    Jim at |

    Funny:……… Once a belief always a belief. Even if you hand them a white piece of paper when they believe it is blue. It will be blue.

  16. Robert Wood
    Robert Wood at |

    Once mild carbon steel ( 650°F, the ferrite lattice will be blended back to its normal state, the tempering (hardening) is removed. I don’t know what the actual temperatures the steel parts are subjected to, but steel doesn’t start turning red until approx. 1,000°F.

    I don’t think I would spend the extra money having my tubes’ ferrous parts “hardened”, only to fire up the amps and have the hardening process reversed while ‘jamming’ on some Pink Floyd….

  17. Curtis
    Curtis at |

    Cryogenic pumping can drop the base pressure in a vacuum tube by several orders of magnitude,and thermionic emission is more efficient in tighter vacuum. So, from a purely technical perspective, there is a real physical phenomenon that objectively improves a major parameter of sound quality, fidelity, and gain, presuming A) the manufacturer didn’t already do this and just not think to mention it because it’s literally basic; and B) the filament was operated under cryogenic conditions, thus burning off the condensed impurity gases into ionic products that react with the get.

  18. pete
    pete at |

    The only reason that cryogenic tubes sound better to some people is because they get sold hand selected tubes with better specs. If these tubes had treatment or not makes no difference.
    Besides, tube components get very hot. That alone would render any treatments useless.

    1. Jean
      Jean at |

      Absolutely correct, I worked for a large company in Australia who would grade valves and sell accordingly


      the components are in a vacuum. Then, any oxygen molecules are absorbed into the getter flashing which traps the remainder. I worked and retired from GE corporation. Cryogenic treatment of Metals was kept under lock and key except for those of us working on the projects. One must remember METALS are CRYSTALLINE. Metal is fragile by nature. The Samurai actually combined non-cryo metal treatment with repeated mechanical applications to swage steel then ice tempering it. We still don’t know what their secret is because the USA sold Gatlin Guns to the British and had them Killed.

  19. Jean
    Jean at |

    Cryogenic treatment is an absolute load of crap,NOS tubes like Siemens EL34 are very close to the old Mullards,sound great too.modern EH EL34 are made in batches some ok some not so ok,nothing to do with cryogenics just materials and the weeding out process.I’ve got EH El34’s, most screen grids glow brightly and when they fail they destroy your Marshall,Cryo or not,they’re fragile.Mullards and Siemens can work to 800v dc on the plates,try that with
    And don’t forget to freeze those headphones,microphones, or just move to Alaska and voila, every valve is cryogenically treated for nothing( no cost).Now phase linear 700’s (I have two) just love the cold….bring it on.

  20. Yves
    Yves at |

    Top scams in hi-end audio:

    Power cords costing thousands
    Silver interconnects costing $$$
    Green marker pens for CDs


    Cryogenized cables.

    Tubes cryo’ed?

  21. Todd D B
    Todd D B at |

    Please don’t damage your CD’s with the little CD Green markers. Yes…treating the edge of CD’s seems believable and it may actually sound better. These green marker pens have been around for years. I would spend hours with my young audiophile group discussing the sonic attributes of applying green marks on the outer edge of a CD. And this goes back More than 30-35 years ago. I would spend hours cleaning the edges of my not so gooey CD’s…no marks on my favorite CD’s…thank you. Little did I know that the green stuff was fouling up the innards of my CD player. I eventually had to get rid of my favorite CD Player – the Carver model with the tube output. I still fought for the positive effects of my “Treated” CD’s. In complete denial. I would inspect my treated CD’s edges and it was easy detecting the glob of green stuff on their edges. Did I put too much on(?) I would treat another group of CD’s while examining the edges and it appeared to me something was scraping the edges of these CD’s. I am not a electrical engineer and I did not take it all apart to find the culprit.
    All I can say now 01/20 is…that even with the greatest of care in using the green marker I still could see the beginning of some scraping on the edges. Oh! This was with done with my new CD player which I paid $350.00 for. Back to cleaning the edges of the green treated CD’s. In my efforts of cleaning it dawned on me – this was 2020. I had purchased new green markers along with the new CD Players two months earlier. Two to be exact. Still nasty looking green edges. Back to cleaning. I also passed the new CD Player and green markers on to a friend who had a knack for taking things apart. I never heard from this friend again. I felt OK about this. I had informed my friend of the problem and he fully understood what he was facing. I finally purchased a CD – SACD player when I upgraded my living room system with my new components and the sound was sweet and detailed. I still have the old CD’s and a much older CD system, a B&0 Beomaster in my den. No SACD’s on the B&O. However, I can live with this. I am still in denial and I think it was user error. I tried and tried, still no answer. Out of touch with my young audiophile group I had to go on with this all alone. I finally gave up and I still had no affirmative results. I do wonder why the vendor did not advertise the sale of the green markers. I can’t help but think these markers were also 35-40 years old sitting on a shelf. They must have a shelf life. But I trusted my audio guide to have all the answers. When I think of it – he was now the same age as the green markers. When I included the CD’s in my final sale, not a word was said about the markers.

    Live and not as wise as I should be………..

  22. silverXnoise
    silverXnoise at |

    The glaring problem with anyone who claims to hear a difference after having spent their own money on cryo tubes is of course the moment they bought into the scam their opinion as an otherwise unbiased listener got torched along with the money they spent on them. This is the same effect that makes expensive wine taste better. Only unbiased listeners who have no skin in the game can reliably judge whether something sounds better or worse, and only through a large enough population of test subjects can any study evaluating an inherently subjective topic be able to claim that their results have any empirical value. The only valid argument that could possibly be made outside of a well-designed blind test is that the cryo’d tubes on offer were likely hand-selected prior to treatment for higher transconductance and lower noise. Beyond that, subjecting vacuum tubes to the process of being cryogenically frozen–an inherently stressful process–could result in units with otherwise unrelated manufacturing defects being eliminated through natural selection (although even this would be difficult to prove, as never has a manufacturer ever endorsed such a process, and what is interpreted as a defect could very well be the result of the abuse a tube undergoes during the cryo process). A shrewd tube buyer can either roll the dice on their purchases, and come to terms with the fact that there can be no guarantees beyond the skill and well-earned reputation of a given manufacturer (where there will still be variance from unit to unit) or they can spend a little extra with a reputable seller who knows how to properly test and rate their wares. With all that said, if paying extra for brand hooey and voodoo magic makes you feel good, then do your thing. No one has the right to judge anyone else for spending their money how they please. Certainly in the field of high-end audio, everyone should be pretty well-served no matter what kind of nude virgin eunuchs blew the glass (or programmed the MatLab performance charts) they’re purchasing.

    1. Henry
      Henry at |

      I would think that if it can be scientifically proven that cryoed tubes result in audible improvements people might be willing to pay the extra $. That might lead manufacturers to see $$$ and jump on the cryo train and cryo treat the metal tube components prior to assembly of the tubes. This should eliminate concerns of, potential expansion differential, problems such as possibly shortened longevity. It might also increase sales of new tubes over sales of decades old NOS tubes.


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