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Old 22nd Feb 2021, 12:02 pm   #22
Plus4db
Triode
 
Join Date: Feb 2021
Location: Stourbridge, West Midlands, UK.
Posts: 21
Default Re: Head demagnetizer cassette

Quote:
Originally Posted by ajgriff View Post
I know that conventional wisdom states that measuring resistance can magnetise heads but I wonder whether or not a quick check with a modern DMM really has much effect?

Alan
I think it's the same since you are putting DC current through them, whether the measuring method be digital or analogue, though probably not a massive issue. It is any case probably a wise precaution.

Interestingly, I have noticed that sometimes on my deck when I set it to record I get a rumbling noise that sounds like the heads are magnetized. It disappears completely when I switch the individual track enable record switches out and in whilst in record. At first I thought they need deoxit but all of the switches have been gone through. It seems remarkably like this action is demagnetizing, which is contrary to received wisdom - Ferrograph particularly said this action would possibly magnetize the heads.

It probably is just dirty switches still, since I don't know how the heads would become magnetized so easily, but it doesn't sound like the higher crackle you normally get with that and out and in once only always removes it.
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