Miyajima Magnetism


I bought a used Miyajima Spirit MC Mono cartridge for playing 78 rpm records last year.  It works OK but it is heavily magnetized.  I noticed it right away when I tried to do set up and it pulled my screwdriver really hard against the side of the body.  The body is made from brass and plastic which are not magnetic so it is not the casing material that is the problem.  It sounds fine but I have the feeling it would sound better if the charge was removed.
Any idea of how to safely demagnetize the thing?  I see cartridge demagnetizers online but I am not sure they would solve this problem.
andysf
It’s magnetic because like all MC cartridges it has a strong magnet in it!

 By all means use a cartridge demagnetizer on it which will have no effect on the attraction you observe. Do not expose it to a bulk demag field however.  

Anyway as long as you keep it away from ferrous screws you’ll be fine!
I guess I should have been more clear that I feel that this is abnormally magnetized.  It is like a refrigerator magnet!  I have had a number of MC cartridges in the past that didn't have this degree of magnetism.  I had a Miyajima Premium here recently that had no magnetic pull at all so I don't think this is typical of the line.
How would you be able to know if it is "abnormally magnetized".  As others have said, it contains a tiny but very powerful magnet or maybe a pair of magnets, by definition.  These produce a field that pervades the structure and evidently extends outside the confines of the body.  This is not at all unusual.  My Ortofon MC2000 will grab a screwdriver right out of my hands (and crush its own cantilever, if I'm not careful.)  Could the coil have become magnetized, due to its proximity to the magnet(s)?  (That's the magnetic field we try to get rid of when we demag an MC.) Yes, but the magnitude of that field would be tiny and not externally detectable, in my opinion.  If you're still concerned, ask the importer.
As I recall, it has a very narrow body when viewed on end.  Perhaps this is the reason its magnetic field is so evident when you bring ferrous materials near it.  But I guarantee you it's normal and/or perhaps exaggerated by a magnetized coil.  Why not carefully demag it and see what happens?  (I would consult the importer, Robin Wyatt, I think, before going ahead with that.)  However, generally a magnetized coil adds only a tiny bit to the field generated by the permanent magnet that makes the thing work as a transducer.
The magnetism on my AT ART9 can pick up stray nails from a roofing job!So, I would assume your Miyajima Spirit is perfectly normal.Cheers, Doug
More to discover