How often do you demagnitize your MC cartridge?

Marakanetz, yes of course there are magnets present in the cartridges. But they do not cause any permanent magnetization of the coils. They cause the coils to be energized by the movement in the field, and induce a current. But, when movement stops, the signal generation stops, and no magnetizing force is left residing in the coils, other than that which is created by the magnet's fields.

However, there is some possibility that there is some content of nickel or other magnetizable metal in some of the solder joints. That could become magnetized. However, I really think that is a low possibility, and would only comprise a negligable amount of material that could be magnetized extremely weakly, and is not in the vicinity of the main field anyway. I think that is not a real factor in this, but I mentioned it anyway.

That's right, you don't want to de-magnetize the magnets (or even attempt to do so)...this may be the exact issue that I eluded to from my research. In essence, continued attempts to de-magnetize the magnets would weaken the electromagnetic fields (or worse, change their characteristics) which would intern reduce the inducted current, etc., etc. causing all kinds of issues with the final signal information.

Thanks, Twl!

Wes

"A little knowledge is some times quite dangerous" so says the old adage. “Fellas”, we are taking about traces of residual magnetization in the coils. So called “pure Copper” coils may have traces of iron or other magnetic materials. After prolonged usage the trace molecules will align themselves into magnetic domains. The net effect is a perturbation of the magnetic field intensity created by the fixed magnets at the position of the coil (the resulting field is the vector sum of the field from the magnetic dipoles in the coil and the field from the fixed magnet). Demagnetization attempts to make the orientation of the dipoles random thus rendering the coil un-magnetized (the sum of the B field is zero, because the random orientation of the magnetic dipoles leads to cancellation.)

I agree that frequent demagnetization may be detrimental to the cartridge. However, I feel strongly, that many cartridges benefit from periodic demagnetization.

I'd say six nines is pretty pure copper.

a-little is enough to wage the gradient of random propagation of so-called residual magnetization and compare its effect to a global demagnitization of the whole cartridge along with permanent magnets. also there's always either 0+ or 0- and it cannot be always clear and pure zero.