How often do you demagnitize your MC cartridge?

I'd say six nines is pretty pure copper.

a-little is enough to wage the gradient of random propagation of so-called residual magnetization and compare its effect to a global demagnitization of the whole cartridge along with permanent magnets. also there's always either 0+ or 0- and it cannot be always clear and pure zero.

It's the chicken that does it.

After reviewing the progress of this thread it's obvious that alien abductions must be on the increase, perhaps it correlates to a lousy economy, and so the great need for demagnetizing cartridges.

We haven't had a good shouting match in a while so I thought I'd resurrect this thread, which I followed when it was new but never contributed to due to zero experience at the time. That has changed.

Our sonics had become surprisingly less involving over the past month or so. Congested, dull, smarmy vocals, etc. Last week Paul even spun a CD for the first time in weeks and the durn thing almost sounded good. IOW, something was seriously wrong and all my tweaking couldn't fix it. I even borrowed Nrchy's chicken but things were still stinky.

Then the Cardas sweep LP showed up with the Wally Analog Shop that I own a share of. I've never de-magnified anything before, but it was here and I figured playing a few frequency sweeps couldn't hurt anything.

Holy M*%#@& of C&@^!!! The magic is back folks, big time. The jaw-dropping sonics we enjoyed from September to January have returned and, we think, have even been surpassed. Playing that record a couple of times sure un-stuck something. The improvements in transient speed, dynamics and clarity extend from the lowest bass to the highest highs. The naturalness of vocals is definitely better than it has ever been. Familiar records have that ability to astonish once again, and a few that had been tossed into the "sell me, I suck" pile have been saved. The toes are tappin'...

Re: the possible magnetization of copper coils. It is not clear to my partner that Cu coils are immune to being magnetized. Whether due to trace impurities or for other reasons the possibility exists. Paul has a Ph.D in metallurgy and 20 years as a mad scientist researching and developing Cu-based alloys for industry. Six 9's Cu is pretty good, but he's worked with purer copper than that and was still able to measure impurities and their effects.

Given the strength of the magnetic field inside an MC cartridge and the tiny mass of the moving end of the cantilever, even the slightest magnetization of that mass could impair its free movement. Those movements are amplified thousands of times before they reach the speaker cones, so any impairment at the pickup end might be audible. FWIW, that's what I think happened. OTOH, neither of us has figured out why playing a frequency sweep would de-gauss anything. Feel free to wade in!

We spun records almost daily for about 5 months before noticing the sonic sludge that the Cardas record seems to have removed. Based on that one data point it seems like 3-4 plays per year might be useful in our system. YMMV and FWIW etc.