8mm Forum: Sound head demagnetizers?

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Posted by Jan Bister (Member # 332) on March 25, 2006, 10:55 PM:

It came to me recently that since I have several working sound projectors, they all could probably use a soundhead demagnetizing treatment. Question is, what do people like to use to do the job? Any particular products that come recommended (or advised against)? I've seen a few demagnetizers on eBay in the $15-$30 range but have no idea if they're usable or junk. Opinions, please. [Smile]

Posted by Dan Lail (Member # 18) on March 25, 2006, 11:40 PM:

Jan, you can still pick up a cheapy at Radio Shack. Make sure the unit is unpluged before demagnatizing.

Posted by Alan Rik (Member # 73) on March 26, 2006, 12:35 AM:

Hi Guys!
Its funny because I was just at Radio Shack last week here in NYC and they dont carry the tip Demagnetizers any longer. They only carry the kind that is in a cassette form.
I asked if they had the other kind and was told no....nobody used Tapes anymore! :0

Posted by Jan Bister (Member # 332) on March 26, 2006, 01:18 AM:

What Alan said... I've never seen a demagnetizer other than the cassette kind at my local "shacks" either.

And Dan - if I unplug it first, how's the bloody thing supposed to work then? [Big Grin]

Posted by Dan Lail (Member # 18) on March 26, 2006, 01:55 AM:

Sorry, I meant unplug the projector. Well, I guess Radio Shack is out of the question. Back To eBay! Here are acouple;

http://cgi.ebay.com/Nortronics-Audio-Head-Demagnetizer-NOS_W0QQitemZ9702614883QQcategoryZ4784QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

http://cgi.ebay.com/REALISTIC-44-225A-HEAD-DEMAGNETIZER-NO-RESERVE_W0QQitemZ5871217304QQcategoryZ15091QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Posted by Andrew Wilson (Member # 538) on March 26, 2006, 05:21 AM:

do you really need them?.i always thougt that the heads were earthed so as to stop magntic build up.andy.

Posted by Jan Bister (Member # 332) on March 26, 2006, 09:52 AM:

Whether they're earthed (rather: grounded) or not is irrelevant to any magnetic buildup occurring over time. It's just a simple matter of all that magnetized oxide stripe running over the head when running a sound film... same with cassette and reel-to-reel audio tapes... after so much time it just happens, and in more extreme cases you'll have audible hiss and loss of high frequencies as a result. A head demagnetizer does just what its name suggests and restores the full frequency/dynamic range of the sound head. Which in turn is good for tape (or stripe) because running recorded tape past a magnetized head can also have a slight erasing effect, causing permanent hiss and loss of high frequencies on the tape itself. (But again that's a more extreme case and not very likely to happen.)
In short, demagnetizing is simply a good idea of maintaining top sound quality, though it's not required nearly as often as a mere cleaning.

Dan, thanks for the links, I've already seen them... (and btw, I was kidding about the unplugging thing) [Big Grin]

actually the one I'm tending to buy looks like this... I used to have one exactly like this back in Germany (which was of course a 220V/50Hz model) and it always worked well... interesting to hear it's supposedly a clone of the Nakamichi DM-10 demagnetizer (itself supposedly a high-end device, though I'm not sure why).

Posted by Mike Peckham (Member # 16) on March 26, 2006, 10:57 AM:

Jan, re: your signiture - that should be fewer brackets not less . [Wink]

Just a silly little thing that I rememeber from school and it seems to be about the only thing that stuck! [Roll Eyes]

Mike

Posted by Douglas Meltzer (Member # 28) on March 26, 2006, 12:57 PM:

Jan,

I purchased a head demagnetizer exactly (ok, similar) to the one in your link a couple years back from The Reel Image. Call Steve at 937-296-9036. The price was $14.95.

Doug

Posted by Andrew Wilson (Member # 538) on March 26, 2006, 01:19 PM:

thanks guys for the info reguarding demag/heads.my next question is how often is it to be done?.andy.

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