Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: simonallaway on October 26, 2010, 11:20:22 am
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I got this email today (as I'm sure others did too) that talks about cryogenic treated tubes. Here's the link (http://tubedepot.com/bsct.html).
Amongst their claims, they have this:
"By reducing and aligning internal stresses of the internal metal structures, this process allows the electrons to flow less inhibited."
Don't electrons flow over the surface of a conductor? How could "aligning internal stresses" help electrons flow "less inhibited"? And wouldn't this freezing process be undone as soon as you fire up the heaters for the first time?
Is this just more cork-sniffery? The prices :huh: and the fact that their trade name's initials are "BS" tell me yes. (I searched the forum here and found no previous discussion here, so apologies if this is a dodo subject).
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Their Hogwash and Partners cryogenic engine has been custom-manufactured in a top-secret shed somewhere in the Inner Hebrides by blind Buddhist monks who happened to work as roadies for Elvis during his Roswell concerts, so their BS stuff must be prime.
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..... by blind Buddhist monks ...
So that's makes your amp more touch-sensitive? :tongue3:
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Don't electrons flow over the surface of a conductor?
I seem to recall, when I was working on electric vehicles, that either DC or AC did not nesecairly travel only over the surfsace of the conductor. Something do do with skin effect. I am sure one of the EEs will elaborate.
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I seem to recall, when I was working on electric vehicles, that either DC or AC did not nesecairly travel only over the surfsace of the conductor. Something do do with skin effect. I am sure one of the EEs will elaborate.
Current density for AC is higher at the surface of a conductor. The higher the frequency, the smaller section of a conductor is effectively used, thru the skin effect.
Skin depth is app. 8,5 mm at 60 Hz (larger than 0000 AWG), 0,7 mm @ 10 KHz (app. 16 AWG) and 0,2 mm @ 100 KHz (app. 26 AWG).
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So can I conclude, that DC does not travel on the skin, but permeates the conductor?
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So can I conclude, that DC does not travel on the skin, but permeates the conductor?
Yes, the whole conductor is used.
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> Don't electrons flow over the surface of a conductor?
Most don't.
Otherwise we'd use only flat or hollow conductors; circular is the worst shape for surface area.
In AC, the mag flux tends to push the current out of the center. The outside does carry more current. Current in the center is never zero, but may be low. In BIG work they do use hollow conductors to save dollars and pounds. In a MHz range a braided-strand construction gives a little more conductance in a given space. At many-MHz it can be useful to silver-plate a coil.
However in other BIG work the issue isn't current density but heat density. Busbars in distribution stations carry BIG current and run HOT. These are made as flat bars, hollow circles, or hollow rectangles so the same pounds of metal has more surface area to throw-off heat.
> How could "aligning internal stresses" help electrons flow "less inhibited"?
Cast copper has random grains. Worked/drawn copper has stressed grain. For best conductivity you anneal copper, relax the grain. Improves conductivity a dozen % or so.
Since a tube is full of non-copper awful conductor, I'm not sure that the metal's "inhibition" really matters.
I don't know how super-cold affects grain structure. I do know that super-cold treatment is considered worthwhile in several mechanical applications where apparently the difference is detectable.
> wouldn't this freezing process be undone as soon as you fire up the heaters for the first time?
Why not just "when returned to room temperature"? That's relatively hot.
A Copper cathode would anneal; but cathodes are Nickel. Nickel may anneal at this temp; but the other electrodes run cooler.
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So w/ all of the theoretical speculations aside, has anyone simply tried a few direct comparrisons to create an unbiased subjective opinion? :smiley:
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So w/ all of the theoretical speculations aside, has anyone simply tried a few direct comparrisons to create an unbiased subjective opinion? :smiley:
Get some tubes, feed them a known reference signal, record the output in high resolution, then send the poor bottles to one of the freezers, get the "treated" tubes back, repeat PB, compare the outputs. Easy.
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I haven't taken the bait on buying them. They've been for sale by a guy on eBay (from what I've seen) and on the few occasions I've asked some questions, I get a very short response that leaves me feeling less inclined to want to buy from this person when it's all said and done.
Your suggestion isn't possible in my world. At best, I could buy a couple treated and a couple untreated and compare that way with my ears and fingers. Was hoping somebody else has already done this?
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I think this subject has come up before. In a past life I was very intimate with tooling - specifically stamping. Some of the tools had .0001-.0002" clearance between punch and die. Obviously alignment is critical and no mater how many times you draw tool steel or buy the best carbide, it's gonna move over time. If you cryo treat these pieces they remain very stable for a long, long time. In a tube the distances between parts vary millions times more in the manufacturing process than the stability a cryo treatment could possibly provide. My BS-o-Meter is coming to life....
In copper the conductivity of the product after annealing has nothing to do with grain structure (alignment, elongation, etc.) as this characteristic is independent of it. However, the oxygen further combining with impurities during the annealing process to cleanse (for lack of a better word) the PURE copper, does, because it binds with the impurities. Oxygen free copper is refined to remove ox and other impurities due to the detrimental effects of these in product applications. Pure Silver is at 106 IACS (conductivity), Pure copper (w/oxygen) is at 103, Oxygen free copper (the stuff we use) is at 101. IM very HO, cryo treatment to somehow improve electrical characteristics is total BS. I have been personally involved with testing conductivity of copper and many different alloys of copper - including: heat treating, pickling, and plating of those variations. Impurities (incumbent or added) or alloying copper affects conductivity, period.
I'd also be willing to bet that screen, grid, and plate materials vary WAY more in composition than any outside secondary "treatment" could possibly have an effect on. I would also wonder what effect cryo has on the glass? Surely the wires and glass have different dynamics at these temperatures? Soft vacuum possibly causing the "difference" in performance? Hmmm....
My BS-o-Meter is pegged...
Jim
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why is this post in the tools board?
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Doesn't Callaham also treat some of his metals to a cryogenic process? And his stuff sells.
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Even if it works, I can't see much use for guitar amps. I'm not exactly sure what benefit you might get. Better high and/or low range reproduction... beyond what the guitar can do in the firsrt place? Maybe a half watt more power? I defy anyone to hear it! It might be useful for hi-fi applications but at what point does it become indistinguishable from SS? What's the point? I'd rather buy 3 sets of decent tubes!
Dave
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Ok,this is my take on the subject.Cryo-treatment of metal definitely improves it's rockwell tested hardness and actually smooths out stress risers below the surface of the metal.That is a fact and it has been used along with shot-peening to improve the service life of metals that are subjected to stresses in aircraft and race cars.Parts like connecting rods and pistons,crankshafts and other high-stress parts.Now putting an already manufactured tube into a deep-freeze with liquid nitrogen to improve its electrical characteristics is another story.
If the metal parts inside a tube were treated BEFORE the tube was assembled,then maybe it would hang together longer.But improving it's electrical characteristics is questionable at best.
The way some metals expand and contract can cause surface stresses that can eventually cause cracks to appear.Does anyone know of tube failures that involve cracked metals other than dropping the tube and breaking it?
It is a pretty gray area to make huge claims about tubes being improved dramatically by cryogenic treatment.
There are indeed stresses on metals in a tube caused by heating and cooling.Can they be reduced by cryogenic treatment?
I cannot say.
I would say we need to know WHAT actually fails inside a tube when it goes bad before being able to definitively say anything about cryogenic treatments being able to do anything at all.
Heat-treated metals,when done properly,can improve the service life dramatically.To completely say otherwise is wrong.Either extreme heat or extreme cold is similar.
We need a lot more information in a laboratory setting before any conclusions can be made here.
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The unmatched feel of Mizuno Grain Flow Forging™
For thousands of years, the forging process has been employed to create some of the world’s finest swords, weapons, and tools. Mizuno’s Grain Flow Forging process brings together the latest forging techniques to create an iron that boasts unbelievable performance and feedback with the soft, consistent feel you expect from Mizuno.
For each of Mizuno’s Grain Flow forged clubs, the journey begins with a single piece of high-quality 1025E Pure Select Mild Carbon steel billet. We carefully heat the billet before beginning the shaping process with a 1000-ton hammer press. This process aligns the grains in the metal and avoids microscopic air bubbles that can form during typical casting processes. Through repeated forging and finishing steps, that raw billet is crafted into irons that boast the classic soft Mizuno feel and feedback that you can trust shot after shot, round after round.
Aligns grain structure throughout clubhead
Enhances clubhead feel and feedback
Soft feel reduces unwanted vibrations
Hmmm, maybe if tubes were made like golf clubs we'd get improved feel, increased feedback, and reduce those unwanted vibrations too?!? :laugh:
Seriously, I think Gerald Weber recommends Cryogenic tubes along with his Sprague Atom capacitors!? :l3:
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You guys kill me! :l2:
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Their Hogwash and Partners cryogenic engine has been custom-manufactured in a top-secret shed somewhere in the Inner Hebrides by blind Buddhist monks who happened to work as roadies for Elvis during his Roswell concerts, so their BS stuff must be prime.
:laugh: :l2: So true. :worthy1:
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more companies doing the cryo thing.... http://www.watfordvalves.com/pdfs/git276.rev_valves.pdf (http://www.watfordvalves.com/pdfs/git276.rev_valves.pdf)
http://www.cryoplus.com/audio.html (http://www.cryoplus.com/audio.html) scroll down and look at the links
(http://www.positive-feedback.com/Issue21/images/snakeoil.jpg)
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Hahah! "...for the cure of all pain and lameness"
Oh how our kids have changed the meaning of the word 'lame' :laugh:
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Remember, skin effect is an RF thing. Calculated effects from this at audio frequencies are a few tenths of 1% MAX. Remember, your guitar amp max output frequency is probably 8-10 kHz and the energy at that frequency is very small.
Cryogenic processing is an annealing process that affects mechanical/physical stresses and perhaps dimensions. Does it have any *audible* effects on electrical performance? That's for you and your budget to decide. IMO, it would be a very minor effect and not discernable in the midst of many other, larger factors, such as tube to tube variability. I'd rather spend my money on tubes, speakers and trannies and maybe precision machined, gold plated turret lugs :icon_biggrin:
http://www.cryogenicsteel.com/2010/05/cryogenic-stress-relief-explained/
cheers,
rob
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I got this email today (as I'm sure others did too) that talks about cryogenic treated tubes. Here's the link (http://tubedepot.com/bsct.html).
Well at $120 a pair, those look mightly like feckin' expensive http://tubedepot.com/bsct-6l6gc-sed.html re-branded Sovtek WXTs. Add a little hype and snake oil and watch the suckers come rollin' in.
Edit - W-h-how! check out the ding-dong prices of their NOS tubes! http://tubedepot.com/newarrivals.html
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Damn Ive never seen golden tubes before they sure think those are :worthy1: :l2: :help: :l4: :l3: :bs:
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W-h-how! check out the ding-dong prices of their NOS tubes!
An audiophool and his money are soon parted. :icon_biggrin:
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Have these tubes gone through the same process as the corpse of Walt Disney?
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Ok,we all smell a rat with cryogenic treated tubes.But we cannot refute that cryogenic treatment of metals does indeed improve it's service life.
It does work,but whether it works on tubes that are already assembled is another story.
I ain't buying any,that's for sure!
I like good tone just like anyone else but an audiophiles obsession is hard to fathom.
It's like guys who sit and listen for all the little noises a tube amp makes and never really get any better at playing the damn guitar.
Drives me nuts.
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What amplifier uses a Western Electric 252A and who would pay $8K a piece for them? :w2:
WE252A Sold (http://tubedepot.com/we-252a-as1.html)
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Have these tubes gone through the same process as the corpse of Walt Disney?
Yes, and he's right next to ex-baseball player Ted Williams' head.
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I actually have some of these cyro tubes, somewhere, but I don't know which ones they are now. They were just some tubes that I needed from older production that happened to have been through whatever the cyro process is. It did not make any difference to me.
Sorry, there could have been an A-B test there, but I blew it!
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"Cryo" treated valves may actually be slightly better than stock valves - but only because the candidates for cryo-ing are tested first, and just the best ones go in the big chiller. :dontknow:
I once left some 12AX7's in the refrigerator overnight, but they still sounded the same the following morning . . . :w2:
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"Cryo" treated valves may actually be slightly better than stock valves - but only because the candidates for cryo-ing are tested first, and just the best ones go in the big chiller. :dontknow:
I once left some 12AX7's in the refrigerator overnight, but they still sounded the same the following morning . . . :w2:
You're lucky they were still there in the morning. If my wife found something like that in the fridge, she'd just toss it out without a second thought - no consultation, nuthin'.
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How about putting night crawlers over night for fishing in the morning? :l2:
She likes going fishing, but.....
Brad :laugh:
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... But we cannot refute that cryogenic treatment of metals does indeed improve it's service life.
It does work,but whether it works on tubes that are already assembled is another story.
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You and I are on the same page with this.
Cryo treatment does make for better tools, but when we say "makes tools last longer, so it must make tubes last longer" we make a big logical leap. The sellers count on you to make this leap, and be excited about buying a "better tube."
It's handy that you can't objectively test whether the tube is really any better.
But when was the last time you stopped using a tube because the plate snapped in half?