Cryo treatment of metal things with music coming out of them

[tedmich]

Aww man.
I was at a most beautiful bell choir concert tonight, performed by members of our church.
Wouldn't you know it, I was actually thinking (I wonder how the bells would sound if they were cryo'd)

thats the only unambiguous cryo-audio effect, the old chem demo with the lead bell dipped into LN2

putting a pyramid over the tubes likely helps too!

[Chuck H]

Actually... Since cryo does affect a structural change in metals, and bells are typically made of some kind of hardenable metal there may actually be a notable tonal change. With a brass wind it's more about the volume of the chamber than anything else (though of course every detail matters) but with a bell you actually hear the metal vibrating. Any improvement to the consistency of the structural nature of the metal is bound to be heard.

Just keeping it real where it is. The trick is to keep someone from selling cryo'd tubes by saying "look what it does for bells! These tubes will give that magic chime!"

[jmaf]

Actually... Since cryo does affect a structural change in metals, and bells are typically made of some kind of hardenable metal there may actually be a notable tonal change.

I've got a good friend, completed his PhD years ago specialised in cryogenics. He told me 100% certainty that cryo'd guitar strings sound different, it's not snake oil.

I'd ask the cryo tube people how they conduct minus 200 kelvin temperature into the internal elements of a tube if there's a relative vacuum between them and the glass. Do the pins conduct all that thermal energy out of the tube via the tiny little leads from pin to plate? The plates have hundreds of times more matter than the tiny leads, especially in big tubes, is that enough to freeze the internal elements to proper cryo temperatures?

I can believe that cryogenics is able to lessen the resistance in tube elements, change their metallic structure, etc, it all is science as long as the elements are treated directly, before tube assembly. But what isn't clear to me is how some folks can buy Sovtek vacuum tubes, dip them into a nitrogen tank and claim it's cryo treated.....

[J M Fahey]

I *understand* cryo treatment is done to metal parts before assembly , or at least before putting them inside the glass envelope.
Anything else is pure, unadultered ...... well, you know it.
What scratches me the wrong way, BAD, is that any molecular rearrangement caused by cryo treatments (or hardening, for that matter), gets *lost* forever as soon said parts reach even halfway the "glowing dull red" temperature, because we get tempering.
A fact known (and used) by even primitive blacksmiths for the last 2000 years.

As a side note, if I were to support some serious weight using surplus tube plates, or sharpen their edges to cut something, I´d understand the usefulness of any treatment which affects its *mechanical* properties.
I might also justify it if, say, they had to stand 60G at some old Atlas or Minuteman Nuclear Missile "brain", ... but to play catcher with a shower of electrons .... c´mon, give me a break.

[jmaf]

I *understand* cryo treatment is done to metal parts before assembly , or at least before putting them inside the glass envelope.
Anything else is pure, unadultered ...... well, you know it.
What scratches me the wrong way, BAD, is that any molecular rearrangement caused by cryo treatments (or hardening, for that matter), gets *lost* forever as soon said parts reach even halfway the "glowing dull red" temperature, because we get tempering.
A fact known (and used) by even primitive blacksmiths for the last 2000 years.

As a side note, if I were to support some serious weight using surplus tube plates, or sharpen their edges to cut something, I´d understand the usefulness of any treatment which affects its *mechanical* properties.
I might also justify it if, say, they had to stand 60G at some old Atlas or Minuteman Nuclear Missile "brain", ... but to play catcher with a shower of electrons .... c´mon, give me a break.

You make good points. Something which is tempered via cryogenics to be used relatively cold, like a guitar string or a surgical knife, is one thing. A cathode that works at 700 degrees Celsius is another... That's a really good point...

As for a catcher of the shower of electrons, maybe, maybe...if by cryogeny the metal molecules were rearranged as to reduce random collisions between electrons, that'd be a better cathode and plate than one where electrons had more trouble going through. By doping a cathode in oxides they were able to reduce the working temperature by over 30% , such advances helped vacuum tubes save heater energy, for example. But you're right, doping something stays there when hot, by dipping something in 200 negative degrees and then heating it to +700 does sound like reversal of the process to me.

[Chuck H]

But you're right, doping something stays there when hot, by dipping something in 200 negative degrees and then heating it to +700 does sound like reversal of the process to me.

It may or may not be a reversal. It depends on the annealing temperature of the metal in question. WRT steel this is usually a high enough temperature that the metal is glowing "medium red" (term used by smiths). So, unless other internal components of the tube reach this kind of heat it's only the cathode that suffers a reversal of the process. Tempering temperatures do not reverse the beneficial changes of cryo treatment. The cryo treatment of steels helps to align the grain structure of the steel and more completely transform the changes made by the hardening process. It doesn't in itself harden the steel. It also does nothing for the electrical properties of metals. And unless the metal in question has some properties that allow it to be hardened there is no benefit at all to cryo treatment.

But I seriously doubt these cryo tubes had their elements dipped prior to construction. So it's probably all moot.

[Steve Conner]

No, they are not "dipped prior to construction". This link shows pictures of the treatment process at one vendor.

https://www.tubeworld.com/kuhltube.htm

The construction process for tubes involves heating all the internal metalwork red-hot with an induction heater, to bake out gas before sealing the tube.

[tedmich]

it makes good sense that high energy states (cherry red glass or metals) can be affected by cooling conditions into low energy (ground if you will) states. The extreme is amorphous alloys where hot crystalline disorder is "frozen" by rapid cooling of the high energy disordered state. Why taking something at a ground state and dipping it in LN2 (or He) should have a large effect on that ground state once it warms up again is a little mysterious to me.

I plan to market homeopathic cryotubes soon!

I suppose a "cold shock" might knock out a percentage of tubes at the margins of the manufacturing quality, thus producing slightly more durable tubes, trial by chilling as it were.

[J M Fahey]

Fool of me, I had forgotten

The construction process for tubes involves heating all the internal metalwork red-hot with an induction heater, to bake out gas before sealing the tube.

This alone kills any and all internal stresses that *might* have existed.
Anyway, we are interested in *electrical* characteristics, not *mechanical* ones.
This is not a 6 shot cylinder in a Ruger 44 Magnum revolver, where heat treatment *is* vital.
(As in being able to play a piano with all your fingers instead of pushing a "play" button with the hook strapped to your arm stump)
Thanks for the link, the page is a mountain of cr*p so big it would make 10 million flies happy.
Not even getting into the dubious "technical explanations", the guy uses *all* the standard Audiophool language.
Zero points in creativity:

The sonic improvements of a over a "factory condition" NOS tube include:

+ tighter focus from top to bottom
+ more holographic 3D soundstage
+ more subtle inner resolution extracted from recordings
+ tighter bass
+ increased dynamic range <--- this one *should* be measurable
+ faster transient response <-- this one too
+ clearer vocals

Of course he keeps it all subjective, will not allow a tube within 1000 miles from a Lab.

[woodyc]

I've got a good friend, completed his PhD years ago specialised in cryogenics. He told me 100% certainty that cryo'd guitar strings sound different, it's not snake oil...

Sorry, but I've got a good friend with a Camaro who specialized in massage and she says your friend is full of crap.

[jmaf]

Sorry, but I've got a good friend with a Camaro who specialized in massage and she says your friend is full of crap.

I don't get it.

[woodyc]

I don't get it.

I was just rebutting your statement with something that I thought was every bit as impressive and convincing, i.e. not much of either.

Maybe it would help if your friend had a name, or you cited the publication where he reported this?

[Enzo]

Well before we turn all that into a pissing contest, perhaps we should also consider that the physical properties of guitar strings impact the sound in a completely different manner from any sort of impact a tube plate physical property might. If we imagine the metal structure of a string vibrating we can imagine ways it may or may not impact the sound it produces. The same thought experiment doesn't seem pertinent to tube structures. They would require a totally different experiment.

[Steve Conner]

That's very true. I can believe that cryo guitar strings would sound different. When we twang a guitar string we are literally hearing the mechanical properties of the metal.

But then, tubes have microphonics caused by their metal structures vibrating. They can be very significant in combo amps, indeed for all I know they may be a major part of the "tube sound".

I have a silicone gasket from a stovetop espresso pot wrapped round the EL84 in my practice amp, to stop the worst of the rattling.

[Enzo]

Well a latte good that will do for you...






OH yes I did...

Thank you, I'll be here all week. Try the veal.