Cartridge Demagnetizer

Making cartridges sound better-than-new
(By Michael M.Gindi - The Absolute Sound Issue 95)

It isn't exactly a case of a better-built mousetrap. It's merely, and most obviously, the way the original mousetrap should have been built in the first place. Still, every reader who owns an expensive moving coil cartridge would do well to beat a path to the Audio Physic cartridge demagnetizer. That is, if they want to catch a magnetic mouse that truly stays caught.

As any moving coil cartridge goes about its complicated business of translating an exhilarating vinyl bobsled ride back into music, it is also sonically self-destructing; a residual magnetism is being built up in the core of its assembly. As time and groove go by, much information on the record starts to get lost in this progressively worsening noise floor, and is no longer being passed on to your preamp. The obvious solution, then, is to use a demagnetizer device that brings the cartridge core back to its original state. "Simple!" you say. So why has it taken until now for someone to do it right?

If you're old enough, and willing, as I am, to date yourself, (Would that be the ultimate narcissistic relationship, or what?) then you may remember using a tape head demagnetizer way-back-when. One would hold the device near the tape head, turn it on, and slowly, withdraw it. This is how a cartridge demagnetiser works as well; it emits a high-frequency, high-amplitude signal (33 kHz in the Audio Physic) and slowly ramps down the amplitude. To my knowledge, aside from the Audio Physic, there are only two other commercial cartridge demagnetisers around; the AudioQuest, which runs off a nine-volt battery, and the Sumiko AC-powered device, the Fluxbuster, that is no longer being sold. The AudioQuest demagnetiser, in my system, has never quite been able to catch the mouse at all.  It has a "well, maybe I hear some improvement" effect that, I think, may be a function of its inability to generate a high enough amplitude at the start. The Sumiko box does have a strong effect, but it also has had me, and several other astute listeners, rather puzzled for years. The improvement, the changed and cleansed sound of your cartridge after using the Sumiko, is obvious.  But equally obvious is an unnatural, metallic, additive, edgy kind of by-product sound that always mysteriously appears right after degaussing, and then mysteriously disappears after a few hours of playing time. Frankly, I never took the time to question why. Fortunately for us, the designer of the Audio Physic demagnetiser did, and has come up with a device that is significantly better than the Sumiko ever was, without any deleterious sonic side effects.

Imagine unwrapping a brand new bar of soap, and washing yourself in a brisk, invigorating, hot needle shower. Now imagine going to your laundry hamper and drying yourself off with yesterday's dirty towel. As I understand it, that is almost exactly what the old Sumiko Fluxbuster does; it snatches defeat from the hands of sonic victory, at the very last moment, by sending a tiny pulse of DC current back into your cartridge as it turns itself off, thus re-magnetizing the core in an odd way. This explanation is not my own - it came third-hand from the designer of the Audio Physic box - but if it's true, it certainly explains what I've been hearing all these years, and why I've learned to never demagnetize a cartridge right before any important listening session. Now, with the Audio Physic, a quick demagnetization after every dozen or so records yields an audible improvement far greater then the "plus six minus two" improvement that resulted from waiting for a Sumiko-demagnetized cartridge to lose the additive side effect.

I can tell you, with complete confidence, that once you try the Audio Physic demagnetiser, you will hear your cartridge as you have never heard it before. Given that every cartridge sounds, shall we say, a good deal less than good before you break it in - a process that takes at least 10 to 20 hours - even if you had used a Sumiko or an AudioQuest at a post break-in point, you would not know the joys buried in your cartridge because of the built-up magnetism. If your cartridge is up to it, after demagnetisation, you will hear a natural purity, a richer silence out of which sounds emerge, and an increased resolution that will leave you with jaws happily agape.  I've tried the Audio Physic (and continue to use it after every five record sides or so) on a van den Hul, a Parnassus, and a Blue Oasis, all with wonderful results. In every case, the cartridge sprang back to life sounding, well, better than ever it had, if you take my word for it and buy one, I'm sure you will agree.

2629 Mabel St.
Berkeley, California 94702
Price: $349.95         
Warranty: Two Years


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