Cryogenic tubes?

[calaverasgrandes]

The other factor is that contraction of two mated parts MAY possibly relieve some compressive residual stresses, but what about tensile ones? Contraction can make them even worse. Plus you got a buncha different materials in a vacuum tube, and those things ALL have different coefficients of thermal expansion. Imagine a part that changes very little with change in temp surrounded by one that changes a great deal. The outer part is gonna shrink like a bitch and bind on the inner one (possibly breaking one or the other), especially when you're talking temp changes in the area of 250 deg. F. where dimensional changes can be measurably large.

Like many audiophile upgrades, this one smacks of desiring (or wishing for) a result more than understanding any physics behind what may or may not be going on...

Thats what occurred to me as well. How is this not gonna eff up tubes? You have metal, glass, mica and plastic. All of those will freeze differently. (I dont beleive the plastic.bakelite bases of some tubes could survive a deep freeze). But the un-like materials contracting and expanding at different rates. I would really like to see these tubes on a distortion analyzer pre and post "dip".

Can we get an injunction against these guys if we can prove they are ruining tubes?

[???????]

Those audiophile systems are usually shown in a shoebox of a living room, with no acoustic treatment.

'nuff said.

I don't think this is accurate. At least not the "usually" part. Most people who have spent tens of thousands on audiophile gear have very well-treated rooms with lots of consideration given to speaker placement, if not total purpose-built listening rooms complete with high-end romex in the wall and duplex outlets. Those guys get crazy. Ever met an audiophile? They're certainly not the type to look for ways to cut corners! By the time they're telling you a different duplex socket makes a difference, they've thought of everything. I promise.

I dipped a toe in that water once, just long enough to find out what was the best turntable, tube amp, and vintage JBLs I could afford. What I saw was pretty terrifying. However, it's not too much different from guitarists who lust after instruments or recordists who lust after U47s. They're just more honest with their materialism, because they can't claim "life's purpose" as its justification.

[???????]

As for the cryo tubes... I have never tried one. There's a guy who cryo treats pickups, pots, jacks, etc. as well.

The science behind it in one sense is sound. A fast, very deep freeze down to near-absolute-zero really does change the structure of the metal permanently, just like heating and then cooling rapidly changes the temper. They cryogenically treat racing engines in cars... it's pretty much commonplace and accepted practice now in some types of auto racing.

In another sense, who says this will make a significant difference on how a vacuum tube reproduces sound? I wish there had been a choice in the poll for "jury's out" because that's how I feel. Absence of evidence is not evidence of absence. I don't know if it matters or not. My instinct would say no, but my instinct (like most of ours) counts for basically nothing, because the science of cryogenics seems so counterintuitive to basic common sense... it's real easy to write something off as bullshit without really understanding why. But I wouldn't have thought it would've made a difference with racing engines either, and it clearly does-- race teams are pragmatic sorts. If it didn't show results on a dyno, they wouldn't do it.

Cryogenics is also widely used in metal baseball bats, knives, guns, golf clubs, brake rotors, etc.

[calaverasgrandes]

well a racing engine is made of metal, not glass and metal. And isnt trying to hold a vacuum.
My dad was an avid audiophile when I was growing up (classical music nut) and we also had a famiily friend who ran an audiophile store. I can even remember the summer that monster cable showed up! Back then it was just like 8 or 10 guage clear jacketed speaker cable with spade lugs shoe horned on. So I am totally familiar with the audiophile thing. I think they fall into two camps. There are the more traditional types that hold great reverence for certain JBL Klipsch and Tannoy speakers as well as certain brands of turntable and amplifier.
Then there are the bleeding edge guys who seem to approach audiophile gear with the premise that if it seems outlandish and unlikely than it must be true. these are the guys buying the $100 power cables and $200 duplex outlets.
It seems to me like the argument for rational analysis was lost on both camps a long while ago. If you try to explain to them that it doesnt matter which way you orient a cable they plug their ears and say I'm not listening to you!
They get even madder if you tell them a spdif cable cant possibly change frequency repsonse with direction! Its transmitting DATA for chrissakes!

[AstroDan]

I don't believe it, but the awesomeness of the umlaut has blinded me into buying a bunch of these.

[???????]

well a racing engine is made of metal, not glass and metal. And isnt trying to hold a vacuum.

I don't think the glass is what the cryo treatment is trying to influence-- I think it's the plate material. And the cryo treatment won't compromise the vacuum, at least I've never heard any reports of that.

But I won't buy them, probably. I have a stash of old-stock tubes in the basement and I love the way they sound in my stuff. What I don't know won't hurt me.

[calaverasgrandes]

well a racing engine is made of metal, not glass and metal. And isnt trying to hold a vacuum.

I don't think the glass is what the cryo treatment is trying to influence-- I think it's the plate material. And the cryo treatment won't compromise the vacuum, at least I've never heard any reports of that.

Well they cant really cryo the plates without freezing the glass too. I am sure the metal has no problem going to -250 degrees, its the glass I am worried about. maybe it can do that fine, but then afterwards is it going to be more or less brittle?

[Snarl 12/8]

well a racing engine... isnt [sic] trying to hold a vacuum.

That's not true.

[calaverasgrandes]

well a racing engine... isnt [sic] trying to hold a vacuum.

That's not true.

True, the racing engine is not going into deep freeze with a vacuum in it, holding that vacuum and coming out the other side again with no gasses. It may go through cycles of compression and rarefaction when it is in use as an engine, but not while it is being frozen I would think.

and yeah I dont always insert my apostrophes for my contractions. get over it.
i waste enough time on here procrastinating without proofing all my posts for the grammar police.

[???????]

have you ever heard any real reports of compromised vacuum due to cryo treatment? If not, it seems like kind of a funny thing to be talking about, maybe.