Tube Amps / Music Electronics
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|3/3/2006 2:06 AM|
|Gibson Knut||Re: more alnico history|
So now we know that most Cobalt comes from Zaire and is therefore expensive and perhaps sometimes unavailable during times of war which seems to be often in Africa. Perhaps little wonder that alnico 5 was scarce. In any case, the Japanese invented alnico in the 1930's and were almost certainly not going to ship cobalt to the US during the war and had no supply of it after the war.
Also read this......
After several years of research, the first “super” magnet is about to be put to use. In 1966 scientists of AFML measured and reported the outstanding magnetocrystalline anisotropy of YCo5 (yttrium/cobalt) and detailed the basic fabrication techniques that could provide permanent magnets of record properties from a large family of compounds of light rare earths and 3d-transition metals (the RCo5’s, where R is yttrium, cerium, praseodyminum, or samarium). As this program continued, samarium-cobalt magnets were developed to the point where their properties make them far superior to magnets of all other materials for most applications.
Initially, a samarium-cobalt magnet will replace platinum-cobalt in traveling-wave tubes where it not only does the focusing much better but is much cheaper. Moreover, its energy product is two to three times greater than that of the alnicoes, with usable coercive forces up to ten times greater, making it possible to replace alnico in many applications with less material, thereby saving space and weight. Also, the extremely high coercive force of samarium-cobalt makes possible application of permanent magnets heretofore considered impractical. Only very recently have engineers begun to appreciate the potential of this material for devices such as motors. These are the only materials other than the ferrites and platinum-cobalt that are really “permanent” magnets (immune to self-demagnetization for any shape). This is particularly important to dynamic applications such as electric motors and generators.
These magnets will have direct application to electronic and communications equipment and will permit more precise, more rapid, and more reliable computerized techniques, particularly in automated and machine processes.
So Samarium Cobalt has been in existance since 1966. FACT!!! Not commercially available until 1996. That's 30 years folks.
My conclusion is that the Black Guard Book is flawed in it's analysis and that Gibson probably didn't have A5 until 1954.
That's my two cents.
|3/3/2006 6:39 AM|
Gibson Knut said:
Remember the original IBM AT with a full-height 5-1/4" hard drive?
Those early voice coil hard disk drives from the 80's had something in them stronger than any AlNiCo, so I'm guessing that large industrial buyers (like IBM) could get SmCo when they wanted it.
|3/3/2006 11:24 AM|
I have no idea what Gibson had access to prior to 1954, but apparently General Electric had some clout. Their legendary 1201 speakers (of which I own one) used Alnico 5 quite far back.
Of interest is an eBay auction for an advertisement in what appears to be the May 1948 issue of Radio Service Dealer magazine for an Alnico 5 GE 1201. The early versions of this speaker were apparently 14.5 oz. magnets. My speaker, from a circa 1950 Allied-Knight radio, is 12.5 oz., and a later version of the 1201 used a 11.5 oz magnet.
So, either everyone's lying about using A5, or....
|3/3/2006 1:19 PM|
I've got a Rickenbacker model 230 solid body guitar with humbuckers on it that uses samarium-cobalt magnets, and it is from 1989. They made these pickups that use these magnets in the early 80's, so I think they were most likely quite available by the 80's.
|3/3/2006 3:03 PM|
Actually, I must conceed that it's neodinium that was not commercially available until 1996. Please accept my apologies on that issue.
The issue of A5 is clearly something that unsettles you lot on this forum. No doubt it will be a source of irritation for evermore unless someone who really knows tells it like it is. You'll probably call him a liar too!
|3/3/2006 4:17 PM|
Gibson Knut wrote:
I can believe the 1996 date for neodymium. Once trade with China opened up, they dominated the rare earth magnet biz.
The sonic properties of industrial materials is so far below the radar of vendors, we all need to sort it out here by trial and error. Not all AlNiCo 5's are the same and it is likely that off-spec batches of A7 and the like have been under-magnetized and sold as A5.
Yore a lyre!
Ya happy, now?
|3/3/2006 7:21 PM|
The article I read said alnico was invented in the US and Japan the same year, not just Japan.
anyway, the fact is that the BlackGuard book shows several tele neck pickups with alnico five BEFORE 1954, which is supposedly when A5 became available. They didn't do some simple stupid test, they did the full blow, those pickups are undisputably alnico five, Leo did have that stuff. I have my friend's '51 tele bridge and the magnets in it, which haven't been recharged, are too strong to be anything but alnico 5, so for me its a done deal, alnico 5 was used commercially before '54.
So what is the argument here really? Is it that GIBSON didn't use A5 before '54? From the looks of it and the dating on the "alnico V" pickup they made it sounds like they didn't use it before '54. I have a very detailed physics report on a '52 Gibson P90 and its alnico III or II, so I'm guessing that from the face of it that gibson didn't use A5 until '54 but Fender DID. What is probably the reason is that anything other than small rods weren't available, so bar magnets probably in A5 weren't availalble commercially til '54.
Now what puzzles me in the forum argument is its use in PAFs. Most of the PAFs players want weren't the real early ones anyway, most are interested in ones made around '59 a'la Jimmy Page's guitar, which most probably used alnico 5 at that late date. So now we're back to alnico IV. Spence found a sample that WAS used in a Gibson product, but what YEAR?? Its also pretty well documented that alnico II was commonly used in PAFs early on and this is from Gibson's own tests on its old products in recreating the reissue LPs in the '80s (so apparently they didn't even have records of what they used back then). So, was A4 used because they got a good deal on some magnets or what because after '54 A5 was commonly available, until the early 60s when according to the Duchoissoir (can't spell his name right....) strat book, when defense industry uses took all the cobalt. Big mystery, only solution is to have an authentically verifiable PAF dated and do a magnet analysis.
Bottom line for me is WHAT alnico SOUNDS most authentic for the tone you're trying to achieve in YOUR design, so alot of this argument is moot and stuff no one will probably ever know for sure unless someone with big bucks does a study on a historic selection of PAFs. Alot of you think that "PAF" guy who posted was blowing smoke or disinformation but he did say that alnico II was the best sounding and what they found in the best sounding PAFs they studied, this is confirmed by Gibson's own research in recreating those pickups in the 80s. I archived that guy's thread and will look at it again, but I think he also said they used A4, A2, and A3 as well as A5. I'llhave to go look again. One thing he said that I'm not so sure about is he said they were wound real loose, I've never opened a real PAF coil so don't know......
Fascinating stuff all.......
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