Demagnatizing Phono Cartridges

Sd: Well, it's okay to stick your neck out, but someone misinformed you a bit. You are not demagnetizing the magnet, you are demagnetizing the wires in the coil. The movements about the proximity of the magnet cause a current flow by induction. The problem is that the close proximity of the magnet to the coil causes the coil to become slightly magnetized over time. It doesn't even have to be in use for this to occur, although it occurs much slower when not in use. When you demagnetize, you are removing as much of the magnetic build up as possible by a controlled induction process that sweeps through a frequency range and neutralizes the magnetic effect. I haven't explained the last part very well, but it's kind of like shaking a towel full of sand out at the beach. If you shake it right--all the sand will fall back to the beach that it came from.

The second thing I would recommend--is try to demagnetize your cartridge. If you have not done it for a year--you will think you just purchased a new cartridge. And you can start the cheap route with the Cardas sweep--only $28--but the Aesthetix works much better.

Hi, Abstract: With due respect, I fully understand that one is not trying to demagnetize the magnet (which, I think, is what I said in my post). The rest of my post tried to make the point that, in almost all cases, the generator assembly, the cartridge housing, and the cantilever would NOT need de-magnetizing. Therefore, by elimination, the only parts left that might be subjected to magnetization would be the coil wire, and maybe the connecting pins. The coil wires themselves would become re-magnetized in a farily short time, perhaps within minutes, due to their proximity to the magnet. The two men that shared their comments with me are both VERY qualified to talk on this subject, and one of them has about 15 years of experience in designing electromagnetic systems. I make no claim of personal expertise in this area. After reading your post, I called my friend who has the background in electromagnetic systems, and his remark was (speaking as an electrical engineer) that there is essentially no merit in demagnetizing the coil wires in either a MM or MC cartridge. However, speaking as an audiophile, he said he fully understands the importance of the analog ritual, and never underestimates the power of expectation (his words, not mine). I'm not trying to start a heated debate here. My own experience with demag'ing a MC cartridge I once owned satisfied me that the procedure, at best, does no harm. My first post wasn't to tell folks "don't de-mag" -- rather, to point out that the procedure is, from an objective standpoint, of dubious value. (All that said, we're still friends, aren't we? We analog enthusiasts have to stick together...)

I have no problems with various opinion, theory, etc. That's what these forums are about. I am a physicist, solid state undergrad training, so I know a bit about the theory--although it sounds like your friend has far more experience than I do. I will still stand behind a difference in clarity after I demagnetize, although now that I do it regularly the difference is much less. Although the configuration is completely different--the principle is not unlike deqaussing a CRT. Instead of the coils it is the grid for the electron gun in the CRT that is being deqaussed. If you do it rarely, it makes a pretty big difference in image quality--if you do it regularly, you can hardly notice a difference.

I'm going to stick to my analog ritual. I think it works--but I buy expensive cables too (electrical engineers don't think much of that either).

van den Hul says that demagnitizing a cartridge, at least with Fluxbuster type devices, ruins them over the long haul. Does anyone know why?

Many cartridge manufacturer's say DON'T use an electronic cartridge demagnetizer. Having purchased a Koetsu RSP through our Tokyo office, I got an email to Mr. Shugano. He is strongly against them. Of course, there is some degradation of the permanent magnet when you use an electronic demagnetizer. There is just a great deal of disagreement as to how much the degradation is. I only use the Cardas Sweep Disc now.