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Alnico Magnet Types


 
11/27/2004 2:56 PM
Josh Pardes
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Alnico Magnet Types
Hi all, I am hoping to gather a little more information on the different Alnico magnet types. I have been using A5 and A2, but have yet to try A3 or A4. Does anyone have experience with these types? If so, how would you describe the sound they produce as compared to A5. I know that A5 is the strongest out of all of the types listed, but how do they rank in descending order? Thanks in advance. I've scoured the internet trying to find this info but there is not much out there beyond the general description of Alnico.
 
11/27/2004 4:57 PM
Spence
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I'm reliably informed that the AlNiCos are numbered in order of when they were first patented as a type. This does not mean that they are asending in magnetic strength. I'm not one of these people with tons of test equiptment but again I am reliably informed that A3 is weaker than A2. A5 is stronger than both these. I haven't used A4 yet but it's thought that the best sounding PAFs used A4.  
I have started using A3 in the neck position on Strats with A2 in middle and bridge. Real nice combo. I am getting a nice woody/bluesy tone on these neck pickups and get away without any noticeable string-pull.  
Combined with A2 in the middle.....real nice in Position 4 and 3. A2 wound to 7.5 K with 42 AWG makes for a really usable bridge tone.
 
 
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11/27/2004 5:21 PM
Dr. Strangelove
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The industry standard document is the Permanent Magnet Materials MMPA 0100-00. It is a 1.44Meg .pdf file freely downloadable at  
<http://www.intl-magnetics.org/pdfs/0100-00.pdf>  
 
A supplement to MMPA-0100 is the Permanent Magnet Guide which may be downloaded at  
<http://www.duramag.com/Engineeringmachining/MMPA_PMG-88.pdf>  
 
-drh  
--
 
11/27/2004 10:58 PM
Josh Pardes
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Hey Doc,  
 
The industry standard document had a lot of good info in it. Thanks for the link. The only thing that I am bummed about is that it didn't have any info on Alnico IV. Do you know much about it? Anyone else?  
 
Thanks,  
 
Josh
 
11/27/2004 7:05 PM
Dr. Strangelove
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If you search on "alnico IV", you eventually find that it is weaker (remanence) than Alnico's 2 and 3, but as resistant to demagnetization (intrinsic coercivity) as Alnico 5-7. In practice, it would probably sound brighter than Alnico II but have less output, an effect you can get with the right amount of ceramic C-5 magnet.  
 
This is probably why it is rarely made -- not enough bang per buck.  
 
The PMM-0100 table II-1 (page 7) for Alnico IV would read sorta like this:  
 
Alnico IV  
MMPA brief designation: 1.2/0.71  
remanence: 5200 gauss  
coercivity: 700 Oersted  
intrinsic coercivity: 710 Oersted  
energy product (BHmax): 1.2 MGOe  
Aluminum: 12%  
Nickel: 26%  
Cobalt: 8%  
Copper: 2%  
(Iron: 52%)  
 
-drh  
--
 
12/30/2004 10:19 AM
Fred Hammon
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Bump for BD  
This was about to get lost at the bottom.
 
12/30/2004 11:45 AM
bd
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Thank you
Thanks........but there are still many unanswered questions....;-)
 
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