Jonathon Carr of Lyra once posted an excellent explanation on VA of why it's safe and effective on some cartridges, ineffective or even dangerous on others. Search there under his user name "jcarr" and you'll find it.
Like Jependleton I use the Cardas Sweep Record. It produces solid results with Koetsu's and Shelters. IME those cartridges rather quickly become unlistenable without it. A treatment at least once a week was necessary with our Shelter 901. No big deal, it takes only 5 minutes.
The ZYX's we've been using for the last six months don't seem to need or react to it as much. It doesn't do any harm AFAIK, but the benefits are subtle (imaginary?) at best. We notice more from the Ayre sweep CD, which presumably de-mags the speaker voice coils.
I've never tried an active demagnetizer. A J VdH scared me off!
Like Jependleton I use the Cardas Sweep Record. It produces solid results with Koetsu's and Shelters. IME those cartridges rather quickly become unlistenable without it. A treatment at least once a week was necessary with our Shelter 901. No big deal, it takes only 5 minutes.
The ZYX's we've been using for the last six months don't seem to need or react to it as much. It doesn't do any harm AFAIK, but the benefits are subtle (imaginary?) at best. We notice more from the Ayre sweep CD, which presumably de-mags the speaker voice coils.
I've never tried an active demagnetizer. A J VdH scared me off!