Cryo for Tubes

Anyone with an informed view of whether cryo treatment of audio tubes actually does anything positive? I’m inclined to think it’s BS.

 

Cryo Treatment for tubes (valves here in the UK) was used for high grade Medical and Military applications to improve performance (reliability) way back in the day....Therefore the claim it improves things is based on scientific data/fact....However, paying double the cost (and more) for a cryo tube because it transforms the sound for HiFi or Guitar Amp applications is perhaps a stretch at best....and at worst, snake oil...IMHO

 

I sent a 6SN7 out to be done many years ago, I found there was an improvement in the sound.
Not night and day but I would say the sound from that tube was clearer or perhaps sharper than one that I kept behind.
You might hear it, you might not.
If it's cheap enough it might be worth doing but I've also heard of premature tube failure so who knows, the tube(s) might have failed for some other reason.

 

I’m inclined to agree with you.

 

When and where? I know that Mullard-Philips had a liquid oxygen and liquid nitrogen facility on its premises sixty or seventy years ago when the company still existed, but that doesn’t mean that it used cryogenic treatment on delicate tubes at any time. It had a lot of other uses for the liquefied gases. Is there any documentation about cryo treatment of tubes from back in the ‘50s, ‘60s or ‘70s in the UK?

Not really, unless there’s documentation somewhere of before & after testing and measurement. I’ve never been able to find any myself, but of course that doesn’t mean such docs don’t exist.

Well said.

 

Yeah …. I rather debated even asking, figuring it ran the risk of opening Pandora’s box …. Cryogenically treated of course.

 

I’m having trouble finding replacement power tubes in the numbers I need from my usual vendors. Debating whether to pay a $8 premium per or not. Putting a tube with different materials (thus different shrink with temp) into deep freeze just seems like a goofy thing to do …….

 

I've had cryo'd and non cryo'd tubes the cryo'd tubes didn't sound better nor did they last longer. Except the tubes in my Dac but those should last for years anyway. I would never pay for cryo'd tubes again.

 

Cryogenic Treatment of Tubes: An Engineer’s Perspective - Effectrode

"In Conclusion
There is variation in the noise and microphony of vacuum tubes because of engineering limitations or to put it another way, tube manufacturers’ ability to accurately and consistently fabricate these complex devices. Mullard (or perhaps it was Sylvania) in their heyday, with vast resources and a wealth of expertise at their disposal got as close as anyone to manufacturing the perfect vacuum tube, however even their tubes were subject to variance in component tolerances which allow electrode movement and sensitivity to microphonic pickup; DC leakage paths in the mica insulation spacers that allow small currents to flow where they shouldn’t and fluctuations in thermionic emission from the cathode oxide coatings, both of which result in self-noise. It would be magical if cryogenic treatment were some kind of ‘silver bullet’ that improves the insulation properties of mica spacers, reduces inter-electrode movement and improves the emission of the cathode coatings to reduce noise and microphony. But I cannot begin to imagine how this works—’magical’ really is the right word to use here because cryogenic treatment of tubes certainly isn’t science—there are no well-considered explanations describing how the cryogenic process works to improve the electrical characteristics of a tube or even the most sparse comparative test results to validate claims for improved performance. The bottom line is that cryogenic treatment is no remedy for inferior materials or defects in tube construction and it won’t transform a rebranded modern manufacture tube into a genuine N.O.S. Mullard a or Sylvania tube—it just doesn’t work that way."

 

I have discussed this issue several times with my 2-3 good friends, experts in the Vacuum tube world. They had and tried cryo lamps and agreed that it was not profitable to invest money in it. The sound results are exactly the same as with "ordinary" lamps.

 

I'll take those one at a time....

I can provide the fact my Mother worked for Mullard (Blackburn) in the 1960s and 1970s on dedicated valve lines that used cryo treatment to Mil-spec valves - then I worked for Philips Electronics for over 12 years and learnt of the work they did (in conjunction with Amperex) to produce cryo valves for the Dutch Navy and Air force in the 1950s, 10960s and early 1970s

Annoyingly, documentation for what was once regarded as classified information is thin on the ground - but the many reference charts and booklets that outline the use of Red, Green, Black and Yellow paint to Mil-spec and Med-spec valves to denote improved design, rare metals and cryo treatment is evidence you'll have to take (or not take)


Thank You....and you too

 

Calling Jim

 

The family history in the valve industry is definitely interesting, but it doesn’t seem to have anything to do with improving the audio quality of preamp or output valves. Cryo-hardening various parts and other bits (e.g., pins) in an effort to create a more durable assembly seems possible - hence the Milspec rating for some such things - but at no time has anyone purporting to do cryo treatment of whole valves or individual valve parts ever presented any before & after measurements to demonstrate what has changed that might in any way affect audio quality. All we get is after-the-fact declarations of more air, more holographic 3-D imaging, more this, and more that, all of it emotional declarations loaded with clearly non-specific breathlessness.

I often wonder if an audiophile employing five thousand dollars worth of cables (to get, according to the manufacturers and reviewers: more air, more separation of individual instruments, more holographic imaging), four thousand dollars worth of audiophile platforms from Symposium (to get, according to the manufacturers and reviewers: more air, more separation of individual instruments, more holographic imaging), two thousand dollars worth of audiophile component fuses from Synergistic ((to get, according to the manufacturers and reviewers: more air, more separation of individual instruments, more holographic imaging), a two thousand dollar rack from Quadraspire (to get, according to the manufacturers and reviewers: more air, more separation of individual instruments, more holographic imaging), two thousand dollars worth of audiophile-size (read: firehose) AC cables (to get, according to the manufacturers and reviewers: more air, more separation of individual instruments, more holographic imaging), and five hundred dollars worth of audiophile hospital-grade AC outlets (to get, according to the manufacturers and reviewers: more air, more separation of individual instruments, more holographic imaging) will just float away into low Earth orbit on all that imaging and separation and hot air.

It seems psychologically probable that anyone considering cryogenically treating all those cables, valves, outlets, component racks (well maybe just the metal posts?) and fuses might not start to think that all the purported air would then be frozen out, all the holographic imaging having to be wrapped in a down-filled parka (to keep out the cold), and all the valves hardened against concussion from all those bomb blasts we encounter in home audio music listening rooms would bring everything down from orbit and back into his listening room for a critical reassessment. I think that moving a phono preamp away from the toroidal transformer in his integrated amp, being absolutely uncompromising about speaker positioning (i.e., actually reorganizing a room in whatever way is needed to give his speakers a fighting chance to do their best), reassessing his cartridge installation and setup skills to either get really good at the task or gain the wisdom to take the TT and cart to someone who can do a better job of it, and ditching those 1,000pF-per-foot speaker cables is an almost entirely cost-free way of provably and definitely audibly improving a system far beyond the claims touted for any and all component cryo-treatment.

 

This might be the next epic......

 

I would really like to understand what is going on with cryotreating (how/why does the treatment itself work and then how/why does this improve SQ) and have researched this plenty. Nothing makes any sense to me . If you have links that try to explain (or would like to explain yourself of course ) what is going on with cryotreating (tubes, cables, any stereo component or even CDs which can be treated) from a scientific point of view, please post as I would love to learn. Thanks!

 

Cryo Tube Controversy – The Chilling Truth
POSTED BY JON @ THETUBESTORE ON JUNE 22, 2015 IN VACUUM TUBES | 18,940 VIEWS | 33 RESPONSES


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.


Cryogenic Treated Vacuum TAD 6L6WGC-STR Tubes.

Cryogenic Treated Vacuum TAD 6L6WGC-STR Tubes.

Cryogenic Treated Vacuum Tung-Sol 12AX7 Tubes.
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.
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.

 

Tried it once myself just for kicks. Total waste IMO.

 

It isn't proven that cryo treatment will improve the sound but since glass shrinks ~ half as much as the steel pins, the delicate vacuum seal between glass and pins could easily be breached at true cryo temperatures - e.g. -320 degrees F.

 

There is a release waver to sign saying the cryotreatment company is not responsible for damage to/issues with the tubes after treatment.

 

Were the tubes cryo'ed whole or the metal parts cryo'ed before assembly? Certainly we know for that cryo treatment impacts the structure of metal and other parts -- Cryogenic Hardening | Cryo Processing | Cryo Metal Treatment

But I've always wondered about cryo treating the whole vacuum sealed, multi material capsule.

 

From what I understand - both.......sub assemblies as well as whole valve batches were put through cryo cycles of various parameters....

As a Graduate Engineer, such a treatment isn't so unusual - it's the same as any heat treatment of the parts for normalising and relieving any isotropic stress....

For those wanting to buy cryo treated valves at a premium - it may well be more oportune to buy Mil-spec or Med-spec valves (tubes) as they've likely already had such a treatment....

 

They typically (I would say >>99.9% of time/tubes) treat the whole tube after it has been made.

Unless of course, they are "disassembling" NOS tubes, treating metal parts (why they would for parts other than the underlying steel contact pins perhaps is beyond me, and I would not recommend doing this either) then "reassembling" them.

I know there are present day tube manufacturers and I dont doubt that some might cryotreat metal parts prior to manufacture.

 

Your right it's BS the same BS that is applied to cables

 

If the tubes look the same, test the same, and sound the same after allegedly being "cryogenically treated", all you're really paying for is for them to be defaced with ugly stickers.