I got back to cassettes in past year so recording a lot of music but erasing tapes on deck takes for ever. I can get tape eraser but I really wonder if it could cause problems. There are metal parts in cassettes, namely the plate under the felt. I would think tape eraser will magnetize that. Last think I'd want is to have a permanent magnet right behind tape to "maybe" affect the recordings or even a head. Any research done on this? I find none on the Net.
Wow! I didn't dig that deep into tape eraser (head) but I remember that the very cheap ones used a magnetized ferrite sitting at 1/2 cm from the tape.
The eraser heads ? Are those the same ? At least, they get magnetized by AC current only when necessary, and they are then lifted down the tape.
The eraser heads ? Are those the same ? At least, they get magnetized by AC current only when necessary, and they are then lifted down the tape.
Proper erasers should all be using AC field that dwindles away, it shouldn't cause the metal parts to magnetize (that part in most of my cassettes is made of non magnetic material, copper usually).
Bulk erasers are very useful. They do not affect the plastic tape just jumble up the magnetism to reduce hiss caused by a permanent magnet eraser.
That was a while ago!
Realistic Magnetic Bulk Tape Eraser Cat. No. 44-210 w/ Original Box Instructions
That was a while ago!
Realistic Magnetic Bulk Tape Eraser Cat. No. 44-210 w/ Original Box Instructions
For those that don't the proper technique is to energise the eraser with the tape at a distance, bring the tape to the eraser and then pull it away smoothly before de-energizing.
Yes I think a proper electromagnetic eraser would act as a head demagnetizer so when pulled away it will demagnetize the metal plate. I should have mentioned I meant those permanent magnet erasers.
I came up with the question while experimenting and erasing cassette with large earth magnet. It works well but while doing it, the metal plate sticks to the magnet like glue. I figured it must be getting magnetized. Probably best to stay away from those permanent magnet erasers.
I use magnet on reel to reel tapes but those has no metal parts so I don't worry. Cassettes have metal bits.
I came up with the question while experimenting and erasing cassette with large earth magnet. It works well but while doing it, the metal plate sticks to the magnet like glue. I figured it must be getting magnetized. Probably best to stay away from those permanent magnet erasers.
I use magnet on reel to reel tapes but those has no metal parts so I don't worry. Cassettes have metal bits.
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When you erase with a permanent magnet you leave the tape in a slightly magnetized condition. This raises the hiss level.
A proper bulk eraser uses an AC field. You reduce the field to zero (either with internal power-down or by slowly moving the tape a few feet away). This leaves nearly no residual magnetism, lowest hiss level.
This also demagnetizes any bits of steel inside the cassette.
It also demagetizes the credit cards in your wallet, jams-up mechanical watches (ask your grandfather), and will probably confuse or ruin your Android/iPhone?
A proper bulk eraser uses an AC field. You reduce the field to zero (either with internal power-down or by slowly moving the tape a few feet away). This leaves nearly no residual magnetism, lowest hiss level.
This also demagnetizes any bits of steel inside the cassette.
It also demagetizes the credit cards in your wallet, jams-up mechanical watches (ask your grandfather), and will probably confuse or ruin your Android/iPhone?
Not always, and not always completely. On the very top qaulity machines, it can do a good job, but many cassette erase heads just did have the power to completely wipe clean the higher energy tapes like Metal.
This came in handy, once, when I helped a friend recover some recordings that her husband had made, and thought he erased. 😉
FWIW, I've never seen a permanent magnet eraser, all I've ever used were AC powered. We had a massive one at work that would do cassette, cart, open reel and even erased U-matic 3/4" video tape. But it would not touch BetaSP video tape. Never made the least bit of difference. BetaSP tape is tough!
I still remember old telephone answering machines that used full sized audio cassette tapes for your recorded message that had a permanent magnet that swung into the erase head position during record. Hey, when you want cheap.
What kind of eraser are you talking about? Proper erasers have an air gap where you put the tape....? I've been using heavy pro degaussers for several years, and my watches and all equipment around the large degaussers never had a problem.
I'm a bit late to the party here, but just for info, the metal shield behind the pressure pad in a musicassette is made of non-magnetic metal. (MuMetal) . It is there to shield the tape inside the cassette from the magnetic field of the erase and play/record heads. If the cassette is made according to the correct specs, this shield cannot be magnetised.
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