Cryogenic treatment of guitars warning

[David Schwab]

My conjecture is likely way off but, if you trust Frank Falbo's veracity, something is going on there that makes an audible difference.

Any ideas?

But I have to say that when those sound files were posted that time of the different bobbin materials with the Zephyr, I sure couldn't hear any difference. And I have good ears for tones.

Different pole piece material sounds different, that we know. So I can appreciate the bimetal construction. But has anyone heard them before and after cryo?

[salvarsan]

Using FEMM 4.2, I modeled the static field for a 1010 steel slug vs. the 430/Ni slug, A5 block on the bottom, and did a |B| plot @3/16" above the slug's top.
There was no difference between the two.

Whatever is going on, it isn't described by the at-rest magnetic model.

[Rick Turner]

I heard Zephyrs at Duncan a while back, and I have a set of three for a long term project making a repro of a guitar that I cobbled together from a '61 or '61 SG Les Paul Custom back in 1967 when I was playing in a band in New York. Jerry Garcia got the guitar from me in 1971 and used it for a while...it's on that GD Live album from '71.

Anyway, the Zephyrs sounded really good to me, and I agree with Frank's assessment of them being very "detailed". I should pull them out and measure them.

[salvarsan]

Barkhausen Noise

If the scientific acticles are credible, magnetic Barkhausen noise (MBN) levels are specific to the grain size in the ferromagnetic substance.

In steels, smaller grains mean less propensity to MBN and broader applied field range over which the noise distributes. Smaller grains correlate with higher permeability and lower coercivity, properties conferred by cryogenic treatment.

Comparison of Magnetic Barkhausen Noise and Sound Velocity Measurements for Characterisation of Steel Microstructures

[tedmich]

Interesting paper, but there is no mention of cryogenic treatment in your reference (that I could find). Are you simply inferring the previously described decrease in grain size due to cryogenic treatments might impact the magnetic Barkhausen noise (MBN) levels measured in this paper? This is not a trivial extension of the logic, I'd avoid making such jumps unless the original authors included this inference in their analysis, and thus subjected it to peer review. Realize too that there are a growing number of "scientific publications" with no traditional peer review, not saying this journal is one but they are increasingly common, complicating extending results even more. Caveat emptor.

[salvarsan]

Interesting paper, but there is no mention of cryogenic treatment in your reference (that I could find). Are you simply inferring the previously described decrease in grain size due to cryogenic treatments might impact the magnetic Barkhausen noise (MBN) levels measured in this paper? This is not a trivial extension of the logic, I'd avoid making such jumps unless the original authors included this inference in their analysis, and thus subjected it to peer review. Realize too that there are a growing number of "scientific publications" with no traditional peer review, not saying this journal is one but they are increasingly common, complicating extending results even more. Caveat emptor.

It is a given by now that the primary effect of cryo treatment on steel is to render finer grain size. Until that paper spelled it out, it was not adequately established (in my mind) that MBN levels in steel correlated well with grain size.

With calibration, MBN grain estimation is more accurate than ultrasound ... for a given alloy. That particular caveat is because MBN decreases with grain size in annealed nickel. These caveats are well-known enough that entire non-destructive testing businesses are founded on them. Indeed, anyone who heat treats automotive and heavy machinery parts has a small test suite.

What aren't adequately documented are conductivity and permeability changes. In electrical conductors, thermal and electrical conductivity track each other. You might expect minor heat conductivity changes in copper and silver after cryo treatment, but all papers I've read comment on thermal without electrical mention. The permeability increase in soft ferromagnetics (with implicit coercivity decrease) would be nice to see mentioned, too.

[salvarsan]

Lest there be any remaining doubt as to the efficacy of magnetic Barkhausen noise testing, SAE defines standard ARP4462 for it's use in defect detection.

[Rick Turner]

When I first got into the whole cold cruel world of cryo treating, the folks I was working with had a pretty simple explanation of what the process does...one that even a non-metallurgist could grasp. They said that the treatment enabled the carbon atoms to find their proper place within the lattice of iron atoms, and so there would be far less in the way of clumps of carbon here and there within the matrix. And if you think back on much of what has come up in this discussion, that explanation makes a lot of sense. Whatever alloy formula we want should be as homogenous as possible with every atom in it's theoretically best position. That's going to minimize grain size and evenly disperse the characteristics imparted by the various added materials.

[tedmich]

To explain the process of DCT in more detail we talked to Neil Plumb, a specialist in the DCT process:

“Hi-Fi is an area of real interest to me, and one whose largely non ferrous components lead the more conventional engineering application of Cryogenics in new directions. Much of the work of audio components is to pass on information, either in the form of electrical signal, or to transmit vibration physically to the atmosphere creating sound waves. Making certain that stress from the manufacturing process is removed allows even the highest quality materials to perform at a level they otherwise won’t achieve.

Tests we carry out with our customers in audio suggest we have positive effects on a material’s ability to transmit music post Cryo. Applications include audio valves in which internal elements are destressed, appear to conduct more power, and show dramatically reduced microphonic tendencies.

Cables in copper and silver show increased ability to conduct music and an extended service life through resistance to work hardening; this translates into on and off stage equipment which sounds better and lasts longer, but also allows the Hi-Fi enthusiast to achieve performance which had been previously unattainable.

We’ve also treated complete amplifiers, and CD players, achieving excellent results. The copper tracks and solder joints within operate more consistently and efficiently allowing the equipment to output a more accurate impression of its source material.

Longstanding work with Phil Taylor at the Dave Gilmour owned ‘Astoria studio’ led to us treating most of their studio cabling and much of their rack mount recording equipment. Dave Gilmour now has all his on stage cables and even some of his guitar strings treated by us and has had an entirely positive on stage and recording experience in pursuit of audio excellence. Other musicians using our Cryo include Brian May of Queen, Green Day and ‘The Edge’ of U2. Our process is supplied to the ‘We will rock you’ stage shows around the world, and we’ve enjoyed excellent reviews of our treated audio valves in both ‘Guitar buyer’ and ‘Guitarist’ magazines.“
from:
http://www.russandrews.com/popindex....DCT_treatment?

http://www.frozensolid.co.uk/audio_s...kcmcisjkkm8is1

CUSTOMERS
At Frozen Solid we pride ourselves on providing a quality service that is second to none in the industry. Over the course of many years we have developed and refined our proprietary treatment recipes for audio components.

There are a few companies around the world that offer cryogenic treatments service for audio components but we feel we have the edge over them when it comes to DCT. In fact there are DCT companies that even promote and market their services by trying to pass off our achievements as their own! But don’t take our word for it, see what our customers and magazines have written about Frozen Solid’s achievements:


“I quickly realised that Deep Cryogenic Treatment [DCT] was an essential ingredient of high quality cable design that I was not prepared to ignore”

Graham Nalty, Designer of the multiple award winning Black Rhodium Cables

The article that started the changed the shape of hi-fi and cables forever...


“Having heard for myself the astonishing effect of cryogenically treating the copper in speaker and interconnect cables, I can’t imagine how this process and its benefits could fade into obscurity”
“The cryogenic process has enhanced the cable’s qualities by increasing solidity of stereo – making voices and instruments more real and in the room – and also increasing the richness of tone and detail”
“If anything, the interconnect cables, when they arrived a little later, proved even greater a revelation than the speaker cables. Max had identified them as A, B and C, and only when I told him that I vastly preferred pair C over the other two did he confirm that this was indeed the cryogenically treated set.”

Keith Howard, Hi-Fi News, July 2001 reviewing Frozen Solid’s DCT process on Max Townshend’s; Townshend Isolda cable



“The tonal differences are clearly discernable, and after all four sets have been given a thorough work out, the results take everybody by surprise...”
“In a word WOW! To freeze or not to freeze? It makes a difference for sure in terms of dynamics and response”
“... the difference between the Cryo vs. Non-Cryo Retros is like the difference between night and day”
“Definitely not a gimmick, nor are they over-priced; worth a look”

Guitar Buyer April 2006 - Reviewing Watford Valves cryo treated by Frozen Solid
Watford Valves, one of Europe's leading suppliers of tested, graded and guaranteed valves to the professional music industry.



“Although the mechanisms and reasons are still not well understood and evidence is largely anecdotal, its use in audio components (consumer and professional) does seem to be growing steadily, thanks to the efforts and facilities of companies like Frozen Solid.... After extensive listening and engineering reliability tests, Tannoy is now applying it to the new Definition series crossover networks and internal cables.”

Editors Award - Hi-fi Choice Magazine September 2009



“Gregory you have definitely convinced me that cryo treatment brings audible improvement to audio cables”

Fabrizio Biagetti, Rome Italy



“It’s been a week now since I got back from Frozen Solid my Kimber PBJ interconnects that they DC Treated and I said I’ll share in this forum my candid opinion about it. First reaction when I tried that was that I was unimpressed. I WAS STUNNED. I preformed two sets of simple tests to possibly tell if there’d really be any significant difference before and after DCT:
A) Test the DC treated PBJs against an untreated one and B) Test it against better cables, in this case against VDH D 102 Mklll and a First Ultimate cable.
The best measurement of course would still be to test it with a similar cable. But in the absence of this, comparing it with a better cable and getting almost the same performance IMO is a reliable enough basis for concluding there is indeed an improvement. I think the point here is not necessarily to transform a good sounding cable to a very expensive sounding one, but rather has to do something wuth maximizing the performance. With all the other factors involved in making cables, i.e. quality of insulation, termination, etc that’s simply impossible. And I do hope nobody would think that now I’m salespitching for Frozen Solid.

Mr Ears, Hi-Fi Choice Forum Member
The DCT process had a noticeably beneficial effect on all the test CDs
Hi-Fi World May 2011

with all this buzz how can it NOT work?

[Mike Sulzer]

To explain the process of DCT in more detail we talked to Neil Plumb, a specialist in the DCT process:

“Much of the work of audio components is to pass on information, either in the form of electrical signal, or to transmit vibration physically to the atmosphere creating sound waves. Making certain that stress from the manufacturing process is removed allows even the highest quality materials to perform at a level they otherwise won’t achieve."

True believing is a wonderful thing, but it almost always turns out to be nonsenses. This time? Who knows? But the probability looks low.

...with all this buzz how can it NOT work?

Yep, with all this buzz about dinosaurs and people walking together in an earth that is just 6000 years old it just has to be true. Right.

[Chuck H]

Here's a thread on some limited testing on cryogenics for pickups done in 2002. As noted, DaveM uses the word decreased when he meant increased WRT the resistance in the bobbin. Strangelove mentions that studies for copper typically show a decrease in resistance but this is only WRT copper alloys. Pure copper typically shows either a slight increase (that can be undone with a heat temper. Bad for pickups) or no change at all. But the results on the magnets seems very positive. Maybe best to cryo the magnets only. It might also be interesting to see what the difference is between cryo treating the completed magnets and cryo treating the poles before charging them.

Re: Damn! Now it's Cryogenic treatments? - AMPAGE Archive

[Rick Turner]

On cables, double blind testing with experienced ears should sort things out a bit. It should be easy enough to A/B test cables that have been treated and those that have not with identical cables from the same batch of wire. If the results are consistent and even just show a difference...bad or good...then there's something that people can hear that we haven't figured out how to measure yet. Wouldn't be the first time that happened in audio.

As for the rest, we're part of the exploratory crew. Maybe not the Lewis and Clark's, but in their footsteps.

My subjective impression of the strings I was treating in the mid-1980s was that the harmonics seemed smoother to me and that the strings lasted longer. I guess I should try all that again and also include some nylon strings as well.

[big_teee]

How about it Rick did you take delivery of the Strat Pickup I sent you for Cryo Testing?
I hope it made the trip?
T

[Rick Turner]

Got it...been in overload mode...a trip to Santa Barbara and back in one day coming back to a CNC machine that lost it's way...it forgot where 0/0/0 was...not good. I'll be back on the R&D train later this week.

[salvarsan]

Yep, with all this buzz about dinosaurs and people walking together in an earth that is just 6000 years old it just has to be true. Right.

Lotta lotta buzz, true. Subjectivism in audio gear marketing is too anecdotal not to contain a preponderance of self delusion mixed with snake oil when it isn't outright contradictory.

I'm slowly finding the science supporting some of the buzz, but important parts are unavailable. Even negative information on copper electrical conductivity changes is absent. Other things, like copper's higher ductility at 77K (WTF?) get lots of ink, and copper's thermal conductivity increase after cryo treatment is by now prosaic in scientific lit.

Does copper's resistance temperature coefficient change significantly when its thermal conductivity is increased? That's an unpleasant possibility if you want to normalize a pickup's DC resistance to 68F.

My immediate estimation is that cryo treatment produces small changes, some of which may be audible in guitar pickups, and not all are good ones.

A finer alnico grain structure post-cryo may not be desirable. Alnico 8's properties derive from a highly self ordered matrix of FeCo crystals interconnected by copper precipitations in the AlNi matrix which are promoted by heat tempering -- this is not something to casually fracture by shrinkage during cryogenic treatment. Alnico 5? Probably less effect from cryo.

So, for now, I'm waiting on parts so I can make a simple reproducible Barkhausen Noise test jig for PAF steel slugs.