None of this cryo business is rocket science, and it has been scientifically well understood for many years now. For those inclined to obtain an in depth technical knowledge on the subject, I refer you to "Phase Transformations in Metals and Alloys" by Porter & Easterling. An excellent text on solid state mass transport phenomenon and phase transistions. Available at Amazon.
The short and skinny on the subject is this:
Processing of most metals involves treatment at higher temperatures. At the higher temperatures the lowest energy state for the organization of the atoms in the solid metal are different than they are at room temperature. So, for example, at high temperatures the atomic lattice might be Face Centered Cubic (FCC) where at low temperatures the structure will be Body Centered Cubic (BCC). There will be a specific temperature at which the metal will undergo a transistion from one to the other. However, this transistion requires movement of atoms (diffusion) to occur within a solid, which takes time to happen, and the rate at which the diffusion can occur become slower the lower the temperature drops. A result of this is that if the temperature is lowered above a certain rate, not all of the metal is able to undergo the transformation before the diffusion beomes too slow for it to occur, so most metals will retain a very small fraction of the high temperature structure after being fully cooled. This retained phase fraction creates stresses within the surrounding low temperature phase material.
Where the cryo treatment comes into play is that materials contract (shrink) as they become colder (thermal expansion and contraction). The rate of thermal contraction of the high temperature phases are typically higher than the low temperature phases, so that the lower in temperature the retained phase is taken, the more that phase is stressed by the surrounding low temperature phase. Stress is a form of energy, and diffusion is an energy activated process, such that if the strain energy becomes sufficiently large, the diffusion will occur despite the low temperature limitiation. At this point, the retained portion of high temperature phase will complete its transformation to the low tempearture phase. The elimiation of the retained high temperature phase reduces the internal stresses within the metal even when returned back to room temperature.
Is there a scientifically proven effect of cryogenic treatment: Absolutely. Whether that change creates a sonic effect in audio equipment I'll leave you all to debate.
Cheers,
Metalman
P.S. The reason my moniker is metalman is because I am a Metallurgist working in R&D for power utilities. I hope this convinces at least some of you that I know a little somethin' about somethin'.
The short and skinny on the subject is this:
Processing of most metals involves treatment at higher temperatures. At the higher temperatures the lowest energy state for the organization of the atoms in the solid metal are different than they are at room temperature. So, for example, at high temperatures the atomic lattice might be Face Centered Cubic (FCC) where at low temperatures the structure will be Body Centered Cubic (BCC). There will be a specific temperature at which the metal will undergo a transistion from one to the other. However, this transistion requires movement of atoms (diffusion) to occur within a solid, which takes time to happen, and the rate at which the diffusion can occur become slower the lower the temperature drops. A result of this is that if the temperature is lowered above a certain rate, not all of the metal is able to undergo the transformation before the diffusion beomes too slow for it to occur, so most metals will retain a very small fraction of the high temperature structure after being fully cooled. This retained phase fraction creates stresses within the surrounding low temperature phase material.
Where the cryo treatment comes into play is that materials contract (shrink) as they become colder (thermal expansion and contraction). The rate of thermal contraction of the high temperature phases are typically higher than the low temperature phases, so that the lower in temperature the retained phase is taken, the more that phase is stressed by the surrounding low temperature phase. Stress is a form of energy, and diffusion is an energy activated process, such that if the strain energy becomes sufficiently large, the diffusion will occur despite the low temperature limitiation. At this point, the retained portion of high temperature phase will complete its transformation to the low tempearture phase. The elimiation of the retained high temperature phase reduces the internal stresses within the metal even when returned back to room temperature.
Is there a scientifically proven effect of cryogenic treatment: Absolutely. Whether that change creates a sonic effect in audio equipment I'll leave you all to debate.
Cheers,
Metalman
P.S. The reason my moniker is metalman is because I am a Metallurgist working in R&D for power utilities. I hope this convinces at least some of you that I know a little somethin' about somethin'.
Thanx Terry...
Did you get my mails about the box of Cat 5 sitting at Cal's for our cryo experiment?
dave
Did you get my mails about the box of Cat 5 sitting at Cal's for our cryo experiment?
dave
Hi metalman,
You like high temperatures created by electrical arcs in metalic conductors and .....
you get really cool toys to play with! 😉
I'm betting that cryo treatment of audio equipment will break it.
-Chris
I think it means two things.
You like high temperatures created by electrical arcs in metalic conductors and .....
you get really cool toys to play with! 😉
I'm betting that cryo treatment of audio equipment will break it.
-Chris
poobah said:
I'm close to my inner child, indeed. That's because life is simple. It's the world that's complicated.
None of this cryo business is rocket science ...
Well, if you define rocket science as lighting the fuse and standing back, then this cryogenics treatment of metal alloys can be quite a bit more complicated.
Some might think it is just dropping metal parts into a tank of liquid gas like helium or Nitrogen or Oxygen or CO2 ... and that may be my point:
There are different gases that do this trick, different melt/boiling points and different metals and alloys (and plastics and glass and ceramics and guitar strings, etc, etc.) react differently to different timing cycles (slow cold to rapid warm, fast cold to slow warm, slow to slow, fast to fast followed by massive heat and on and on) .... that it really is quite complicated. Much more complicated than say, forging titanium for golf club shafts or for use in rocket science ... :>)
Well, if you define rocket science as lighting the fuse and standing back, then this cryogenics treatment of metal alloys can be quite a bit more complicated.
Some might think it is just dropping metal parts into a tank of liquid gas like helium or Nitrogen or Oxygen or CO2 ... and that may be my point:
There are different gases that do this trick, different melt/boiling points and different metals and alloys (and plastics and glass and ceramics and guitar strings, etc, etc.) react differently to different timing cycles (slow cold to rapid warm, fast cold to slow warm, slow to slow, fast to fast followed by massive heat and on and on) .... that it really is quite complicated. Much more complicated than say, forging titanium for golf club shafts or for use in rocket science ... :>)
Barrett/Nix/Tetelman describes the FCC austenite to BCC ferrite transition as a diffusionless phase transformation. (The Principals of Engineering Materials, Prentice-Hall, 1973, pp311...(Yah, I'm an OLD guy...but not of course, as old as that "other guy", he knows who he is...). The process starts at a martensite start temperature, and finishes at the martensite finish temperature, and is a result of atomic movement less than one atomic distance.metalman said:
metalman said:
Anybody can make themselves out to be anything they wish on the web forums, so we can't go by that. I would however, assume such based solely on the content of your post. Nice.
Cheers, John
Yeah, I guess it is a good idea to provide proof of statements about ones qualifications. This is me!
Not quite right, maybe from the older reference.
"Structure and Properties of Engineering Alloys", Smith, 1981, p. 27
The crystal structure produced by the martensitic transformation in plain-carbon steel changes from BCC to body-centered tetragonal (BCT).
But then this is a non-equilibrium transistion that happens during quenching (very rapid temperature decrease), that does indeed occur as a diffusionless process as the cooling is to rapid to accomodate diffusion. I was more generally referring to the issue of retained austenite (FCC) in a ferrite or pearlite (BCC) steel that undergoes an equilibrium transition during slow cooling. This process does involve diffusion.
Yeah, I guess it is a matter of perspective, although from your comment I take it that you've never actually tried to forge Titanium. Not anywhere as simple as you might imagine!
Cheers, Terry
metalman said:
I have no reason whatsoever not to believe you and i am sure nobody else has either, but it doesn't really prove anything. That is the danger of the internet. You could post a link to anybodys CV and claim it's yours. 🙂
Metalman,
What might all this cryo stuff be doing to wire-grade copper? In english ( just a notch or two below geek-speak), if possible...
😉
What might all this cryo stuff be doing to wire-grade copper? In english ( just a notch or two below geek-speak), if possible...
😉
I'll give it a whirl ...
I already mentioned that the presence of unconverted (retained) phases from higher temperatures put the surrounding material under stress (tension). That stress is communicated between the atoms via the outer orbital electrons, which are the same electrons that impart bulk conductivity to the copper. This internal stress makes it harder for the electrons to be kicked free from their atoms to participate in electrical conduction. So one possible effect is that the localized zones around the retained phases impart a non-uniform conductivity within the copper. This could potentially result in smearing of an electrical signal. If you have a precision resistance meter and a load test machine, you can do a neat little experiment where you slowly impart a stress on a copper bar and watch its resistance increase. Same sort of thing but happening on a much smaller scale at small randomly located spots throughout the conductor.
Another possibility is one I haven't mentioned yet involving grain boundaries. Inside a single grain (or crystal) of a metal, all the atoms are arranged in a precise and orderly pattern (picture neat little rows). The pattern is not alinged between two adjacent grains, and as thermodynamics tries to align atoms between the mismatching patterns chaos erupts again creating localized stresses. This is the reason why jet fan blades cast as a single crystal are much much stronger than their many grained bretheren. With the grain boudaries, the cryo treatment allows the atoms at the grain boudary to do one extra jostle to move into a more oredered structure, i.e. the width of region of choas at the grain boundary becomes smaller. Again, the arguement for its effect on an electrical audio signal is that it reduces the effects of the grain boundary interactions with the signal. Same arguement that applies for copper of larger sized long grains having better sound.
I KNOW I'm going to get seriously flamed for this post, so let me state in advance that I have tried to generalize and simplify this explanation a great deal, so anyone who has some knowledge in this area IS going to be able to blow holes in my arguements. That's a good thing because it means people will be discussing the issue and thinking about it.
Dave, yes I did. I actually sent you a couple of e-mails, but I suspect they may have dissappeared into the ether of netspace. I'm going to try to attend the upcoming event at your place, and then I could bring the wire back with me and cryo it for you. Did you know that LN is cheaper than milk or gasoline? Hell you can now buy drinking water that is more expensive. A world gone mad I tell you!
Cheers, Terry
Terry,
Just checked -- no mail from you, but it could easily have got thrown out with the SPAM -- i hate it that these spammers haave made email unreliable.
You know how to contact Cal?
Make sure you pull off some as a unmodded benchmark before frezzing. I have some here too.
dave
Just checked -- no mail from you, but it could easily have got thrown out with the SPAM -- i hate it that these spammers haave made email unreliable.
You know how to contact Cal?
Make sure you pull off some as a unmodded benchmark before frezzing. I have some here too.
dave
All of the technical info provided by Metalman is very interesting, and points to possible changes in metal structures and possible effects that those changes may have on audio (whatever "smearing" is), but none of the audio cryo-treating people performs any testing of any kind to determine if their treatment regime is actually changing the metals, or to what extent they are changed, nevermind the audio effects of those changes, and don't ask them about accelerated life testing to determine if they are actually doing more harm than good, assuming there is a possibility of doing some good.
As far as I can tell, the whole "cryo treatment industry" involved in audio tweeks consists of a few marketing guys who may or may not have a dewer of liquid nitrogen in their garages depending on whether they are deluded by their own sales pitches or are just plain grifters.
If anyone wants to do some cryo treatment, I suggest they get some liquid nitrogen and do it themselves. You can rest assured that you know as much about it as the guys who would charge you an arm and a leg to do it for you (assuming that they actually do anything but take your money to the bank). Liquid nitrogen is used in so many industries that it is neither expensive nor difficult to obtain. You can keep it for many hours in a thermos - just don't screw the lid on tight!
I_F
As far as I can tell, the whole "cryo treatment industry" involved in audio tweeks consists of a few marketing guys who may or may not have a dewer of liquid nitrogen in their garages depending on whether they are deluded by their own sales pitches or are just plain grifters.
If anyone wants to do some cryo treatment, I suggest they get some liquid nitrogen and do it themselves. You can rest assured that you know as much about it as the guys who would charge you an arm and a leg to do it for you (assuming that they actually do anything but take your money to the bank). Liquid nitrogen is used in so many industries that it is neither expensive nor difficult to obtain. You can keep it for many hours in a thermos - just don't screw the lid on tight!
I_F
posted by metalman:
OK... so I'm with you here. Does this effect occur in the same way as we would expect a strain to behave... i.e. stretch a wire, the resistance goes up (from end to end of course)?
Now the phase-tensile-compressive-gradients you speak of make sense as there is a rough parallel in the way a casting cools. When the casting has cooled the outsides are in tension... with the insides in compression. With this in mind, wouldn't at least some of the stress gradients (and differing phase states) you mention be minimized by paying more attention as to how rapidly, or slowly, the metal was cooled, as opposed to how it was returned to ambient? I know that the best castings are done in super heated molds where cooling takes place very slowly.
I ask because the current audio-cryo stuff seems to be the opposite... rapid cooling and slow return... seems backward.
Now as far as the thieves and liars are concerned, rapid implies drama... and wires/parts that have been through a "right of passage" will sound better. Slow roasting sells anything from peanuts to barbeque... so that has to sound better too.
I know you are planning some testing, are different cooling and recovery profiles part of the plan? I would ask for a prediction... but you're way too smart...
😉
OK... so I'm with you here. Does this effect occur in the same way as we would expect a strain to behave... i.e. stretch a wire, the resistance goes up (from end to end of course)?
Now the phase-tensile-compressive-gradients you speak of make sense as there is a rough parallel in the way a casting cools. When the casting has cooled the outsides are in tension... with the insides in compression. With this in mind, wouldn't at least some of the stress gradients (and differing phase states) you mention be minimized by paying more attention as to how rapidly, or slowly, the metal was cooled, as opposed to how it was returned to ambient? I know that the best castings are done in super heated molds where cooling takes place very slowly.
I ask because the current audio-cryo stuff seems to be the opposite... rapid cooling and slow return... seems backward.
Now as far as the thieves and liars are concerned, rapid implies drama... and wires/parts that have been through a "right of passage" will sound better. Slow roasting sells anything from peanuts to barbeque... so that has to sound better too.
I know you are planning some testing, are different cooling and recovery profiles part of the plan? I would ask for a prediction... but you're way too smart...
😉
I_Forgot said:
... and make sure thermos is kept upright in your car (unless you want crygenically treated car mats, or worse, shoes).
Wait a minute ... maybe we are onto something here. Just wait for next lot of Nike ads :
stronger, faster, cooler - cryogenically treated runners (tm) 😉
PS make sure your foot isn't in them, they tend to go black and really smelly after being cryogenically treated. Not audiophiley at all 😎
I_Forgot said:
There are certainly some who do not fall into the above category. Moray -- who posted earlier, and Bill Perkins (in excess of 10k vacuum tubes with much repeat business), who both came out of the Meitner thing already mentioned. And i can tell you -- neither of those guys are marketing guys. I'm sure there are others. Just like in the general cable business, there are gems & there are snakes.
dave
A proof ...
maybe not for cryogenic tretament, but for a similar tweak, and it also comes from another "well known and trusted guy" who is not "marketing guy", but a designer (and a good one, many would argue).
I think heads would roll at Philips and Sony (CD "fathers") if clarified CDs sounded this much different ! In fact it seems Clarifier is completely changing binary content on an existing CD.
Just thinking about it makes me dizzy.
maybe not for cryogenic tretament, but for a similar tweak, and it also comes from another "well known and trusted guy" who is not "marketing guy", but a designer (and a good one, many would argue).
I think heads would roll at Philips and Sony (CD "fathers") if clarified CDs sounded this much different ! In fact it seems Clarifier is completely changing binary content on an existing CD.
Just thinking about it makes me dizzy.
Attachments
Absolute nonsense...
Where does this "not a marketing guy" phrase come from? Somebody sells something, especially something THEY created, but they are not marketing it?
I don't want to stoop to the "Chewbacca defense"... but it doesn't make sense.
Advertisement is not marketing?
Placing a product for sale is not marketing?
Extoling the virtues of said product is not marketing?
What then is marketing? I know marketing guys that are not liars. This is one example of a liar that is not a marketing guy?
😕
Where does this "not a marketing guy" phrase come from? Somebody sells something, especially something THEY created, but they are not marketing it?
I don't want to stoop to the "Chewbacca defense"... but it doesn't make sense.
Advertisement is not marketing?
Placing a product for sale is not marketing?
Extoling the virtues of said product is not marketing?
What then is marketing? I know marketing guys that are not liars. This is one example of a liar that is not a marketing guy?
😕
I_Forgot said:
In fact cryogenic treatment of electronic devices occurs on daily basis at pretty much any observatory. Back thinned CCDs and radio detectors are routinely cooled down to liquid Nitrogen (and some to MUCH lower temperatures - like neutrino and muon ionisation detectors that are cooled down to almost single Kelvin digits) and then brought back to ambient regularly, many every day.
Do we observe "better" performance after cooling ? Of course ! But only compared to room temperature. Unfortunately, well depth, noise, linearity, quantum efficiency or any other measurable electrical characteristic seems to stay EXACTLY the same - day in, day out. Same for performance of passives around them (tracks, connectors, wires, insulators you name it).
Are audio applications that much more critical to detect something astronomers do not know about ? Using your ears, no less ?
Hmmm...
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