Cartridge De-Mag: Is it necessary?

Hi Bundy, You might not get a lot of responses to your post because this issue has been covered extensively in this forum (and in the fora on other sites) Do a couple searches and you'll see what I'm talking about.

I will tell you that A.J. van den Hul (www.vandenhul.com) has a lot to say about why one SHOULDN'T use a cartridge demagnetizer.

Per Van Den Hul, it may actually be detrimental in the long run:

http://www.vandenhul.com/artpap/phono_faq.htm#20

It depends on the cartridge. It's essential for Shelter's and Koetsu's, has little or no effect on a ZYX. Don't know about Benz, sorry.

You can de-mag more safely (and cheaply) with the Cardas record, probably without risking the damage from active devices that VdH warns about .

Also, what Nsgarch said. :-)

I know you asked about Benz, but FYI, I've posed this question directly and personally to Mr. John Grado. He says his moving iron cartridges do not need demagnetizing ... ever.

Let me add another comment here, at the risk of repeating not only myself, but I'm sure countless others who have undoubtedly made this same point:

Just what (in a phono cartridge) do we think we're going to demagnetize folks? It would have to be made of ferrous materials, right, or it couldn't become magnetized in the first place, right? In a MC cartridge, the only ferrous materials are the pole pieces and the magnet(s). I can't imagine why on earth anybody would want to demag those! You want them to be as powerful as possible!

If the armature (that little cross- or square- shaped thing at the end of the cantilever that the coils are wound on) were made of iron (like in a transformer or solenoid) it could become magnetized. But using a ferrous material in that location would ruin the performance of the cartridge due to the electrical choking action of the metal core.

I think currently there's a high-end cartridge which has an armature made of mu metal, a material whose primary characteristic is its ability to shield things from magnetic fields. But most armatures are made of synthetics which are more compatible with the cantilever suspension materials against which they're compressed.

Let me further add that the fluctuating magnetic field that could be developed around the cartridge coil windings by sending a small alternating current through them would be too weak to do much of anything, good or bad.

Any demagnetization that I or any of my friends have done have Always,slightly,improved sound.However the improvements(a bit more air and opened up stage)don't last all that long.The process has to be repeated fairly often,and for that reason,I myself only do it on the EVE of a listening session,when my most HYPER-CRITICAL friends come over!THANK GOD that is not too often!!Any other times I have to rely on the fact that I like the sound of my stuff as is!!

Good heavens! We need the cartridge magnets to retain their flux -- not the other way round!:)
Do head Nsgarch's & others' posts & leave the cartridges "magnetized". If you wish to get rid of STATIC build up the TT just make sure you've grounded the arm well enough -- or just touch the arm (preamp on mute -- or change the selector switch -- of course).
If a "demagnetizer" actually does what its name implies, you'll end up looking for a new cartridge! Cheers

My Lyra Helikon needs demag after several months of use. The improvements are immediately discernable especially in the mid to treble frequencies.

In fact, Lyra recommends frequent demag of their cartridges. Presumably, the recommendation to demag depends on the cartridge manufacturer