There is information hear about the test disc mentioned.
http://store.acousticsounds.com/index.cfm?get=detail&title_id=35532

I found some discussion of this here: vinylengine.com forum.
http://www.vinylengine.com/turntable_forum/viewtopic.php?f=18&t=56821

There is also a Google Group which has been discussing demagnification.
https://groups.google.com/forum/#!topic/rec.audio.high-end/vTYWC-GJqTs

I also found some information about De-magnefication for CDs/DVDs.
http://www.gcaudio.com/resources/howtos/demagnetization.html
...and various other sites ask about CD-DVD De-magnification.


--

Paul T. Jackson
Trescott Research
Steilacoom, WA
[log in to unmask]
trescottresearch.com <http://trescottresearch.com/>
     support writing: Plateauareawriters.org
<http://plateauareawriters.org/>
     support live music: Gatewayconcertband.org
<http://gatewayconcertband.org/>