Why demagnitize an optical reader?


I've read numerous times now that folks state to demagnetize a CD or optical disc before playing it for best fidelity and accuracy.  I don't see how an optical device, which is non magnetic and made from non magnetic materials benefits from a demag process.   Does anyone have any information to support this?  Other than hype, of course.

Robert

128x128spatialking

Showing 4 responses by geoffkait

I’m not a big fan of the magnetic ink theory for the simple reason the ink on the CD label could only contain trace ferrous material, at best. I.e., not enough ferrous material to produce a magnetic field of sufficient strength to affect either the CD laser or any electronic elements in proximity to the CD. And certainly nowhere near the magnetic field strength of big honking transformers such as found in a modded Oppo CD player, for example. And perhaps not even near the strength of induced magnetic fields in wire. For the same sort of reason I’m not a fan of the magnetizable metal layer theory, either, as the CD metal layers are quite pure aluminum, gold or alloys. So, there must be a different theory.

The problem with the explanation in the last post is that the electric static charge on a CD is entirely different from a magnetic field. A demagnetizer removes a magnetic field, assuming there is one, whereas an anti static fluid or ionizer is required to remove an electric static charge, assuming there is one.
One imagines the naysayers would have a conniption if people said that demagnetizers work for interconnects, just like for CDs and vinyl, you know, given that there are no magnetizable elements in the conductors or anywhere else in the interconnects.