MC Cartridge Degaussing Demagnetizing


An old topic that I would like to re-visit and would appreciate Jonathan Carr weighing in on.

What does LYRA use and/or recommend to degauss their (MC) cartridges?

What happened to the Audio Physic demagnetizer?
Immedia seems to have dropped them.

Since many companies/manufacturers of phono carts will NOT discuss degaussing their carts and/or the material of the armature is it OK to use the Cardas or Analogue Productions LPs instead?

How EXACTLY do these sweep records degauss a cartridge?

Is it OK to assume that IF a sweep record helps a cartridge sound better then a degausser or demagnetizer is appropriate?

Assuming no DC content and a very low level voltage and current... How EXACTLY can an AC rising and then falling signal fed into the cartridge cause the cartridge to fail prematurely?

Thanks! :^)
Tom M.
jhendrixfan
Elizabeth: Here is a WONDERFUL treatise by Jonathan Carr on this topic:

http://www.audioasylum.com/audio/vinyl/messages/61192.html

Hard to believe that it is almost 10 years old! WOW!!

Check this out too:

http://www.youtube.com/watch?v=1TkJ_wwkbNA

I prefer that you not "cross-channel short" the tonearm leads but rather use shorting RCA jacks OR use the Radio Shack jumpers (cat # 278-001, $6.99) to jumper each channel's center conductor to its respective outer shield.
I also suggest using a rather dynamic record and playing for a minute or so with the output cables shorted/jumpered.

Please share your findings with us - either way.
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Regarding Fluxbusting.... When you turn on the device, it does its job and then stops. The end of cycle is the actual turning off the unit and then switching to the other half of the cartridge to demag that. What I do is disconnect the unit from the cartridge when it stops demaging and THEN turn it to the other half after disconnecting it...that way I do not get the "metalic sound" you describe.
Thanks everyone for your nice reponses! :)
Elizabeth - Read Jonathan Carr's treatise on this topic (from 10 years ago!) and you will see why your Dynavector does not need demagnetizing. The "more it is done the more it needs it" is complete sophistry in a technical sense. It is a psycho-acoustic thing. Initially you notice a distinct difference and then you tend to focus on it and do it more often. If scared, simply do the "shorting the output" thing whilst playing an LP.

Stringreen: You are very much correct and Mr. Carr discusses why your lovely Benz benefits from Demag.
I have a LYRA Dorian so I know that Jonathan recommends demag for it but NOT for my Denon DL-103S.

As for the Sumiko FB-1 it was alleged that they emit a small DC voltage at the end of the "cycle" that leaves the cartridge a bit "metal sounding" for a few hours.

Does anyone know what happened to the Audio Physic device?

Does anyone know what device LYRA uses and/or recommends for their cartridges?

Overall Demag/Degauss has its place - especially in a reference system. I think it is important to know if it even applies to the cartridge you are using and if it is even worth addressing. However just understand that, when applicable, it is a very REAL phenomenon - particularly with MC carts.
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I have a Fluxbuster (old) and use it about every month or so. It DOES make a difference on my Benz Ebony LP. Some cartridge manufacturers don't approve of it because they use wire that connects the pins to the coil that is so thin and delicate, that they are fearful that they can melt or be burned by the demagging device. I know that Benz recommends it for their cartridges. Check with the manufacturer of yours for clarity.
Thanks for your responses - much appreciated but I still need more information. Especially on cartridge demagnetizers degaussers.

Yes, I read Mr. Carr's piece and that is what my questions were based on. So I need some additional insight.

Some facts:
Larryi - it is Van Den Hul and not Benz that states that demagnetizing is not needed and is bad. He states it as follows:

The physics behind the armature is quite interesting. (Correct: I have no life.) It's made of what vdH calls "practically Weisz-domain–free iron." He goes on to explain: "Ferromagnetic materials don't change their magnetic polarization per atom, but rather in aggregates or domains. When the size of these domains is decreased, each magnetic field change is responded to by the material's polarization in a higher number of smaller steps. This expresses itself in a reduced-modulation noise level. The modulator's square armature shape is also very helpful here. The result is a signal waveform practically free of steps. The much-reduced noise floor results in an enhanced sense of resolution and spaciousness. This noise floor is the sum of modulation noise plus surface noise. With the strongly reduced modulation noise, only the record-surface noise is left. The extremely-low-level groove information, therefore, is no longer masked, and that means the sense of spaciousness and resolution improves a lot."

Since I have seen no formal technical treatise on "Weisz domain-free iron" anywhere I view his claims as complete sophistry. However, if it is shown empirically that his cartridges do not benefit from any method of degaussing/demagnetizing then so be it. That may be a salient selling point for his products.

Marakanetz: Don't call me Dude....
please read up on this as demagnetizing an MC cartridge is somewhat of a misleading moniker. It is really degaussing the armature - if it is magnetic - obviously not the magnets themselves.

I still need someone to precisely explain how the sweep records actually work.
Dude MC cartridges should be ALWAYS magnetized and NEVER demagnetized. As simple as that.
Somewhere on this site is a very long and thoughtful piece on the subject by Jonathan Carr.

The use of a record to effect very mild degaussing would be the "safe," though far less effective way to do degaussing. What you do is short the output of cartridge to maximize the current flow in the cartridge's circuit (e.g., insert a plug into the RCA jack from the tonearm wire that shorts the two conductors).

The manufacturer that is dead set against degaussing is, I believe, Benz. They say that while it may improve the sound for a short while after doing the degaussing, with each such procedure, the sound will be degraded so that in the long run, the process ruins the cartridge.