|
Post by dixiechicken on Jul 12, 2007 4:54:06 GMT -7
I see that some tubdealers claim to deepfreeze -196 degree celsius - i.e. liquid Nitrogen temperatures. This:
Is this really true - in any way - or is it completebullsh@t??? To relieve stress in glass you dont usually deepfreeze it - you heat it up & gently cool it - right?
Does anybody know anything about this??
Cheers: Dixiechicken
|
|
SG123
Full Member
Posts: 221
|
Post by SG123 on Jul 12, 2007 7:46:00 GMT -7
|
|
|
Post by dixiechicken on Jul 12, 2007 9:34:40 GMT -7
I asked Mike at KCA-NOS tubes about this - I got this reply from him: ;D ;D ;D
Cheers: Dixiechicken
|
|
|
Post by Lefty on Jul 12, 2007 12:50:36 GMT -7
Let's just say...Bullsh1t on that one.
|
|
|
Post by dixiechicken on Jul 12, 2007 13:19:59 GMT -7
Yeah I followed the link that SG123 put up to an earlier discussion on this subject. I read Myles comments - what he had done testing the tubes etc etc.
Maybe this would work out fine if you were trying to turn your +500$ NOS KT66 tubes into a pair of superconducting frisbees. ;D
Cheers: Dixiechicken
|
|
|
Post by Sam A. on Jul 12, 2007 13:44:30 GMT -7
TOTAL B.S. Some manufactures are starting to do this with hospital quality AC cables. Now that is tweakalicious....
Sam
|
|
|
Post by billyguitar on Jul 12, 2007 19:30:25 GMT -7
It would seem bogus with tubes but other things would need careful a/b-ing to know. I think when they first came out I tried those cryo treated strings. They didn't make any impression on me either way.
|
|
|
Post by nitehawk55 on Jul 12, 2007 20:13:21 GMT -7
Strange thing with this cryo treating BS is I've seen some guys offering this done on vintage NOS tubes . Now why would you want to do that ?? DUH !!
|
|
|
Post by myles on Jul 14, 2007 11:46:08 GMT -7
I have played with these for a number of years.
I have found no benefit and actually have found a drawback possibly.
This process from a structural point of view will make most metals harder and thus more brittle. The metal elements in a tube are not treated to temper them or make them harder, in fact we want the opposite so things inside when heated and cooled, expand and contract, do not work harden as quickly. All metals will work harden over time when worked and eventually fracture. I found the life of these treated tubes is in a limited study, shorter. I have also seen that moving the amp while still hot (not a good idea) tends to cause more problems with these tubes.
A TUBE IS NOT A STRUTURAL DEVICE. THE LAST THING YOU WANT IS SOMETHING TIGHTER OR STIFFER. YOU WANT A MALLABLE METAL THAT WILL EXPAND AND CONTRACT WITH THE GLASS BOTTLE AND THE MICA AT ABOUT THE SAME RATE FOR AS LONG AS POSSIBLE. IF THIS IS NOT ACCOMPLISHED THE TUBE WILL QUICKLY BECOME PHYSICALLY MICROPHONIC.
NO sonic changes, spec changes, or curve traces changed pre and post treatment with one exception that does not happen all the time - the emissions on the treated tube is lower than before treatment. This may indicate that the cathode material or the impurities in the cathode material changed in some manner or there could be some other change.
On the shorter life issue - I suspect that the barium (that silver getter flash that gets smaller over time and use) is less effective after treatment. This barium is the stuff that over the life of the tube keeps absorbing stray unwanted gasses and O2 that come from impure materials in the tube as you cannot get the tube to be 100% clean and pure in all the internal materials when manufactured. NOS tubes were much better in this respect but still far from perfect. This is one reason NOS tube life is higher than tubes of current production.
As another point of useless information .... my wife says I am a vast storehouse of useless information .... the current tube maker with the highest degree of "clean materials" and a lack of impurities is JJ.
The tubes from China are inconsistent due to a lack of QA in production and assembly so as great as many of these tubes sound you need to get them from a vendor that tests them well.
The Russian tubes have plate materials and other internal metals that vary and there are metal alloys used that are very inconsistent. I have found things in the plate material alloy that have no reason to be there, metals used in marine applications (monel as an example ... used in propellor shafts on boats and ships). Much of the Russian plate material comes from scrapped Russian Naval ships so this is a factor. Once again ... use a tube vendor you can trust and one with a decent warranty.
Back to cryo stuff - Now keep in mind this is my personal expericence with maybe a dozen sets of these tubes of various output tube types. Your own personal experience may be different.
|
|
|
Post by myles on Jul 14, 2007 11:54:02 GMT -7
I guess I can put this another way .... rather than my thoughts in the above post.....
I have a cool black dog ... Lab mix.
If you send me a set of guitar strings I will let my dog lick them and they will sound better and last longer for only $50 per set of strings.
By the way ... those cryo strings that may have started this whole idea years ago ..... again, the last thing you want is strings that are more brittle and work harden faster (shorter life).
Plus .... try this at home .... safe as there are no voltages necessary, just a scale such as a simple bass fishing scale will work....
Take a .032 or whatever string and bring it to pitch and then attach a scale to it to measure tension when deflected 1/4" or 1/2" or whatever. Then try the same test with a cryo treated string. Interesting isn't it?
|
|
|
Post by dixiechicken on Jul 14, 2007 13:17:12 GMT -7
Thanks Myles - DC here!
I emailed Mike at KCA about this and as you can see by his answer earlier in this thread - it was hardly a thumbs up. Your opinions about brittleness of metall parts in the tubes after cryo treatment jibes with my own suspicions on the subject.
Certainly changes can occur in various materials with such a treatment - all change is not for the better unfortunately.
Cheers: Dixiechicken
|
|
dave
New Member
Posts: 7
|
Post by dave on Jul 14, 2007 13:24:26 GMT -7
I guess I can put this another way .... rather than my thoughts in the above post..... By the way ... those cryo strings that may have started this whole idea years ago ..... again, the last thing you want is strings that are more brittle and work harden faster (shorter life). Plus .... try this at home .... safe as there are no voltages necessary, just a scale such as a simple bass fishing scale will work.... Take a .032 or whatever string and bring it to pitch and then attach a scale to it to measure tension when deflected 1/4" or 1/2" or whatever. Then try the same test with a cryo treated string. Interesting isn't it? Now I dont know if you are kidding or not. What happens? Nothing? I hate bogus science and cryotreatment is top of the list. It is impossible to change the structural state of a substance at room temperature, where diffusion rates are already non-existant, by lowering the temperature even further! Tempering and annealing processes require heat. End of story. This is typical of the idiocy that gets written about cryotreatment www.frozensolid.co.uk/science.htmWhat makes me laugh is the line where it says ...'Upon soak completion the material may require a post temper. The tempering operation is carried out within the same processing chamber or one of our other tempering ovens.' i.e cooling doesnt work and you have to heat it to see any change. Bogus science. Theres a lot of it about. Another example are the claims made for those 'magnetic' water softeners. Clamp a magnet to a pipe and all the water hardness disappears... rubbish (again). There are many others. I could go on...
|
|
|
Post by myles on Jul 15, 2007 15:17:55 GMT -7
As a side note ..... since this is all about stuff getting super cold, I thought I post a pix of one of the hydrogen furnaces at GT that hit about 4000 degrees F to do some of the heat treating of the five clad plate material on the 6L6GE and burn off impurties. I'd hate to be a piece of tube plate material .... 4000F one day and ultra below zero the next? It's a wonder these tube things even work at all!
|
|