cartridge demagnetization

Here is some more info about it
MC Cartridge Degaussing Demagnetizing

Miyajima MC transformer has buid in demag. option.
I've seen Luxman Demags on ebay very often

I use the demagnetizing cuts (side 2, tracks 2 & 3: pink noise) on Analogue Productions Ultimate Test LP. Was skeptical at first, but the results were unambiguous on my Koetsu.

I demag my cartridges. Has anyone noticed that it takes a few sides to smooth out after demagnetizing your cartridge. It always sounds a little bright to me at first, and then things settle down and sounds great.

Safest way to degauss cartridges (including MM cartridges) is passively as suggested by Terry9. I happen to use the Cardas/Stan Ricker test record, but any good (meaning as high a level as possible from a vinyl groove!) frequency sweep test track will do.

The only "drawback" is you should run it through the frequency sweep track two or three times for a 'thorough' job ;~) But you cannot do ANY damage; not even to MM or MI cartridges, and you will get benefits with both types of cartridges which you will never get by running an active degaussing signal through the cartridge's coils -- for the following reasons:

1. MM cartridges actually CAN benefit from degaussing. They have coils with hundreds of windings of insulated copper wire. The problem is if you run an active degaussing current through those big coils, you will create a strong enough electromagnetic field to most likely completely demagnetize the tiny/weak little moving magnet! However, running a GROOVE-GENERATED frequency sweep signal through those big coils (via the little moving magnet or moving iron element) will be sufficient to "burn in" the coil windings -- actually you're burning-in the interface between the copper coil wire and its insulation.
2. Additionally, the frequency sweep signal will help "re-form" any capacitors in the phonoamp's input circuit -- I'm thinking primarily about the RIAA equalization circuit.

These are both "maintenence benefits" you WILL hear; and which you will never realize if you (rightly!) avoid degaussing your MM or MI cartridge with an active demagnetizer!

Using a frequency sweep with MC cartridges gets you the same two additional benefits listed above (plus there's no chance of damaging those delicate coils which just seem to get finer and more fragile every year!) There is very little ferrous material in most modern day MC cartridges, so not much (if anything) to degauss anyway! And of course, you are doing nothing to 'clean up' the input circuitry of your phonostage.

Enjoying vinyl is all about taking the time necessary to get the most out of the medium. Playing a frequency sweep track (even half a dozen times, every six months!) will take all of 15 minutes. So what's the big deal?
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