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Cryo Treated Valves ... ??
OK, so when I asked about the bias setting on the Lumleys, Keith suggested
that the owner should be running Svets in there, as did several others, so I went looking for some sources and prices. Watford Valves have some " Cryo - Treated " Svet 6550C's for a couple of quid more than the 'standard' types. See http://www.watfordvalves.com/products.asp?id=10 This is a new one on me. Has anyone tried them ? Is there really any sound or performance improvement from them ? Or have they maybe been cooled in a big vat of the snake oil that everyone on here is so fond of talking about ? Arfa |
Cryo Treated Valves ... ??
"Arfa Daily" wrote in message ... OK, so when I asked about the bias setting on the Lumleys, Keith suggested that the owner should be running Svets in there, as did several others, so I went looking for some sources and prices. Watford Valves have some " Cryo - Treated " Svet 6550C's for a couple of quid more than the 'standard' types. See http://www.watfordvalves.com/products.asp?id=10 This is a new one on me. Has anyone tried them ? Is there really any sound or performance improvement from them ? Or have they maybe been cooled in a big vat of the snake oil that everyone on here is so fond of talking about ? Arfa This is an interesting one - another example of 'belief mechanisms' in operation, but one where I *don't believe* it works. I don't *know* because I haven't tried them myself, I've no intention of trying them and, worse yet, I wouldn't *believe* anybody who did try them and said it did make a difference!! From what little Physics I do remember, I thought it was quite the opposite of "At very cold temperatures (below -312°F), the molecules will align in a more uniform, compact structure through the removal of kinetic energy." - I thought the only way molecules could move in solid objects was if you *heated* them up! (Which is why blacksmiths ring the anvil when bashing red-hot metal about - to 'jiggle' the molecules!) Also, FWIW, if someone flogged me 'Cryo' valves I wouldn't even *believe* they had been so treated anyway - how many fridges go down to -312°F...??? (Oh, OK - most valve dealers have got a cryo plant out in the back somewhere then?) (WTF is "CYROGENTIC" [sic] anyway - a proprietory name or one which *implies* the real thing without being the real thing - like 'Mapleen Syrup'....?? :-) |
Cryo Treated Valves ... ??
In article , Keith G
wrote: From what little Physics I do remember, I thought it was quite the opposite of "At very cold temperatures (below -312°F), the molecules will align in a more uniform, compact structure through the removal of kinetic energy." - I thought the only way molecules could move in solid objects was if you *heated* them up! (Which is why blacksmiths ring the anvil when bashing red-hot metal about - to 'jiggle' the molecules!) In essence, you are correct and the quote is either incorrect or misleading. :-) If you wish materials to 'crystallise' then in general you may find it useful to cool them slowly *through the range around their melting or softening point*. I'd suspect that the materials used for the electrodes in 'valves' would be well below this at normal room temperature. Hence it isn't clear cooling them to very low temperatures will do what is claimed. Hard to see that if will affect the 'structure' of the vacuum, either... :-) Hence IIUC you'd have to first heat the valve to the point where the materials were starting to melt, then slowly cool it *if* you wanted any serious recrystallisation. But simply using it and then allowing it to cool to room temperature would probably do much the same. Also, FWIW, if someone flogged me 'Cryo' valves I wouldn't even *believe* they had been so treated anyway - how many fridges go down to -312°F...??? (Oh, OK - most valve dealers have got a cryo plant out in the back somewhere then?) I'm trying to work out what "-312 deg F' actually means as a real temperature... :-) I'd thought that science and engineering moved on to Kelvins some decades ago. Certainly, I stopped even thinking with F units many years ago. Do they charge in pounds, shillings, and pence? :-) Sounds to me like they just dunk the things in a bucket of liquid nitrogen (77K). You can buy that by the bucketfull from your friendly local 'liquid air' supplier. (Someone like BOC, Air Liquide, or a local uni) (WTF is "CYROGENTIC" [sic] anyway - a proprietory name or one which *implies* the real thing without being the real thing - like 'Mapleen Syrup'....?? :-) As distinct from Potcheen Syrup... :-) Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
Cryo Treated Valves ... ??
"Arfa Daily" wrote in message ... OK, so when I asked about the bias setting on the Lumleys, Keith suggested that the owner should be running Svets in there, as did several others, so I went looking for some sources and prices. Watford Valves have some " Cryo - Treated " Svet 6550C's for a couple of quid more than the 'standard' types. See http://www.watfordvalves.com/products.asp?id=10 This is a new one on me. Has anyone tried them ? Is there really any sound or performance improvement from them ? Or have they maybe been cooled in a big vat of the snake oil that everyone on here is so fond of talking about ? Arfa My guess is you'd be better spending the extra on upgrading circuit components but I have never actually tried those cryogenically treated valves. I'll try and find my notes but I remember changing psu diodes over to the faster UF5408 & UF4007. The 6550 cathodes now stand on 1 ohm w/w for metering, several other changes like reduced global f/b and changes to both the driver and input boards but as I say I'll try and find my original notes. That was all of 10 years ago... Mike |
Cryo Treated Valves ... ??
"Jim Lesurf" wrote in message ... In article , Keith G wrote: From what little Physics I do remember, I thought it was quite the opposite of "At very cold temperatures (below -312°F), the molecules will align in a more uniform, compact structure through the removal of kinetic energy." - I thought the only way molecules could move in solid objects was if you *heated* them up! (Which is why blacksmiths ring the anvil when bashing red-hot metal about - to 'jiggle' the molecules!) In essence, you are correct and the quote is either incorrect or misleading. :-) If you wish materials to 'crystallise' then in general you may find it useful to cool them slowly *through the range around their melting or softening point*. Yes, I'd call that 'annealing'.... I'd suspect that the materials used for the electrodes in 'valves' would be well below this at normal room temperature. Hence it isn't clear cooling them to very low temperatures will do what is claimed. Exactly!! Hard to see that if will affect the 'structure' of the vacuum, either... :-) Hence IIUC you'd have to first heat the valve to the point where the materials were starting to melt, then slowly cool it *if* you wanted any serious recrystallisation. But simply using it and then allowing it to cool to room temperature would probably do much the same. You could always heat them up and hold them at an angle of 71 deg pointing North and then hit them smartly wiv a hammer - it would make them very slightly 'magnetic'.... :-) |
Cryo Treated Valves ... ??
Keith G wrote From what little Physics I do remember, I thought it was quite the opposite of "At very cold temperatures (below -312°F), the molecules will align in a more uniform, compact structure through the removal of kinetic energy." - I thought the only way molecules could move in solid objects was if you *heated* them up! (Which is why blacksmiths ring the anvil when bashing red-hot metal about - to 'jiggle' the molecules!) In essence, you are correct and the quote is either incorrect or misleading. :-) If you wish materials to 'crystallise' then in general you may find it useful to cool them slowly *through the range around their melting or softening point*. Yes, I'd call that 'annealing'.... I'd suspect that the materials used for the electrodes in 'valves' would be well below this at normal room temperature. Hence it isn't clear cooling them to very low temperatures will do what is claimed. Exactly!! Hard to see that if will affect the 'structure' of the vacuum, either... :-) Hence IIUC you'd have to first heat the valve to the point where the materials were starting to melt, then slowly cool it *if* you wanted any serious recrystallisation. But simply using it and then allowing it to cool to room temperature would probably do much the same. You could always heat them up and hold them at an angle of 71 deg pointing North and then hit them smartly wiv a hammer - it would make them very slightly 'magnetic'.... Worked with Miller and some Lucas dynamos, sometimes, reputedly :-) It must take a while for the heat to escape. How do they know when it's done? How do they avoid cracking the glass or the metal, or weakening the joints between dissimilar materials? There seems to be common in the claims something about relieving "internal stresses", whatever that means. It may be plausible...I forget if I ever knew anything about metal at low temperatures...presumably crystals can be unformed by making them either very big or very small. Perhaps it is the equivalent of work hardening, where discontinuities are squeezed out of crystal boundaries? Perhaps that then effects the way that perveance-enhancing constituents of the cathode alloy migrate to the surface? cheers, Ian |
Cryo Treated Valves ... ??
"Ian Iveson" wrote You could always heat them up and hold them at an angle of 71 deg pointing North and then hit them smartly wiv a hammer - it would make them very slightly 'magnetic'.... Worked with Miller and some Lucas dynamos, sometimes, reputedly :-) It must take a while for the heat to escape. How do they know when it's done? How do they avoid cracking the glass or the metal, or weakening the joints between dissimilar materials? There seems to be common in the claims something about relieving "internal stresses", whatever that means. It may be plausible...I forget if I ever knew anything about metal at low temperatures...presumably crystals can be unformed by making them either very big or very small. Perhaps it is the equivalent of work hardening, where discontinuities are squeezed out of crystal boundaries? Perhaps that then effects the way that perveance-enhancing constituents of the cathode alloy migrate to the surface? I'm not qualified to comment, but I will say that, in general, I *believe* the opposite - the appropriate application of heat allows change in solid objects, the application of extreme cold prevents it..... |
Cryo Treated Valves ... ??
"Keith G" wrote in message
... "Ian Iveson" wrote You could always heat them up and hold them at an angle of 71 deg pointing North and then hit them smartly wiv a hammer - it would make them very slightly 'magnetic'.... Worked with Miller and some Lucas dynamos, sometimes, reputedly :-) It must take a while for the heat to escape. How do they know when it's done? How do they avoid cracking the glass or the metal, or weakening the joints between dissimilar materials? There seems to be common in the claims something about relieving "internal stresses", whatever that means. It may be plausible...I forget if I ever knew anything about metal at low temperatures...presumably crystals can be unformed by making them either very big or very small. Perhaps it is the equivalent of work hardening, where discontinuities are squeezed out of crystal boundaries? Perhaps that then effects the way that perveance-enhancing constituents of the cathode alloy migrate to the surface? I'm not qualified to comment, but I will say that, in general, I *believe* the opposite - the appropriate application of heat allows change in solid objects, the application of extreme cold prevents it..... http://www.frozensolid.co.uk/science.htm for example. Like other forms of cold working, it drives out the dislocations from the structure. Seems also to encourage the formation of carbide in iron, and who knows what other structural changes in other metals and alloys, similar to those caused by pressure perhaps. cheers, Ian |
Cryo Treated Valves ... ??
"Arfa Daily" wrote in message
OK, so when I asked about the bias setting on the Lumleys, Keith suggested that the owner should be running Svets in there, as did several others, so I went looking for some sources and prices. Watford Valves have some " Cryo - Treated " Svet 6550C's for a couple of quid more than the 'standard' types. See http://www.watfordvalves.com/products.asp?id=10 What was it that P.T. Barnum said? This is a new one on me. Cryogenic treatment of just about anything, followed by pseudoscientific claims for improved performance is decades old. Has anyone tried them ? Admitting this is IMO like admitting to being a born sucker. Is there really any sound or performance improvement from them ? One that is readily demonstrable in a sighted evaluation, of course. Or have they maybe been cooled in a big vat of the snake oil that everyone on here is so fond of talking about ? Very good, grasshopper. You have learned well! ;-) |
Cryo Treated Valves ... ??
"Arny Krueger" wrote in message ... "Arfa Daily" wrote in message OK, so when I asked about the bias setting on the Lumleys, Keith suggested that the owner should be running Svets in there, as did several others, so I went looking for some sources and prices. Watford Valves have some " Cryo - Treated " Svet 6550C's for a couple of quid more than the 'standard' types. See http://www.watfordvalves.com/products.asp?id=10 What was it that P.T. Barnum said? This is a new one on me. Cryogenic treatment of just about anything, followed by pseudoscientific claims for improved performance is decades old. No, honestly Arny. I've been around in the electronic service business for 35 years, and cut my teeth on valves as an apprentice. I still service a lot of valve gear now. In all of those years, I have never heard of anyone doing this to a valve, and claiming that it alters the characteristics in any way. Having now looked, there does seem to be a lot of people on the web providing the service, and making all sorts of claims about it, but from a service engineers point of view, I've never before heard of it, or seen any articles in the trade press about it. Has anyone tried them ? Admitting this is IMO like admitting to being a born sucker. I'm inclined to agree, but I was just interested to see if anyone actually did come back on this one with any claims - at the risk of starting another " I can hear the difference between bell wire and electricity board cable " debate. It just might have been that someone had some proper measurements that they'd done, but it would be hard to carry out such measurements, as you would have to do them on a before and after basis on the same valve. Is there really any sound or performance improvement from them ? One that is readily demonstrable in a sighted evaluation, of course. Again, I was just looking for an opinion from anyone that might have been tempted to have tried them. I certainly wasn't about to recommend them to my customer, no matter what anyone said, but if there had have been anyone come back and say anything positive about them, then I might myself have been tempted to get a couple ( no matter how much of a mug you or anyone else might think that that makes me ), purely from a research interest point of view. Or have they maybe been cooled in a big vat of the snake oil that everyone on here is so fond of talking about ? Very good, grasshopper. You have learned well! ;-) Glad I've pleased you ... Arfa |
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