How to Erase Sony Microcassettes

by Fred Decker
Ciaran Griffin/Stockbyte/Getty Images

Although microcassettes from manufacturers such as Sony have been largely superseded by digital voice recorders, they're still available and in widespread use. Cassettes can be erased and re-used multiple times, which makes this a low-cost technology. Businesses must sometimes erase recordings from microcassettes before disposal, especially if they contain confidential information such as legal or medical consultations. One cassette at a time can be erased in the recorder, or they can be erased through the use of a magnetic bulk tape eraser/degausser.

Single Tape

Step 1

Insert the microcassette into your recorder. If your recorder offers multiple tape speeds -- usually 1.2 and 2.4 centimeters per second -- choose the higher speed.

Step 2

Insert a dummy microphone into the mic jack. Many recorders came with a dummy microphone, which is just a microphone plug with no wiring attached. If you don't have one, plug a set of earbuds into the microphone jack.

Press the "Record" button on your recorder, and let it record over the full length of the tape. When finished, remove the microcassette and reuse or discard it.

Bulk Tape Eraser

Step 1

Gather your microcassettes together at a work space that's at least five feet from the nearest computer or other delicate electronic device. Remove your watch, and place it at least five feet way.

Step 2

Hold the bulk tape eraser away from the cassettes, and slide its thumb switch to the "On" position.

Step 3

Position the eraser on top of your first cassette, and move it in a circular pattern for six to 10 seconds to erase the tape.

Step 4

Repeat, until you reach the duty cycle for your eraser. For an inexpensive consumer model, that's usually one minute or six to seven microcassettes.

Move the eraser away from the tapes by 2 to 3 feet, then release the "On" button. Rest the bulk eraser for at least 20 minutes before blanking your next batch of microcassettes.


  • Bulk tape erasers generate a very strong magnetic field, which can permanently damage digital watches, MP3 players, cellular phones, computers, tablets and -- most importantly -- heart pacemakers. Ensure the eraser is at least 5 feet from any of these devices, and if you use a pacemaker have someone else erase the tapes for you.


  • If your cassette begins to erase itself then stops after a brief interval, your recorder might be equipped with a voice-activation feature. Look for a button or switch labeled "VOR" or "VOX," and change it to the "Off" position.
  • If your cassette doesn't begin recording at all, look for a button labeled "Pause" or "Hold," and switch it to the "Off" position.
  • If you can't press the "Record" button after the microcassette is in your recorder, that means the tape's write-protect tabs have been removed. You'll see a pair of small rectangular holes in the microcassette, on the side opposite the tape itself. Cover those with clear tape, and try again.
  • Handheld bulk tape erasers resemble the steam irons used for pressing clothes, except they're smaller and squarer in shape. If you need to erase tapes in greater quantity, commercial suppliers carry medium-duty tabletop units and heavy-duty freestanding degaussers. They can also be used to erase standard audiocassettes, videotapes and computer disks.


Photo Credits

  • Ciaran Griffin/Stockbyte/Getty Images

About the Author

Fred Decker is a trained chef and certified food-safety trainer. Decker wrote for the Saint John, New Brunswick Telegraph-Journal, and has been published in Canada's Hospitality and Foodservice magazine. He's held positions selling computers, insurance and mutual funds, and was educated at Memorial University of Newfoundland and the Northern Alberta Institute of Technology.

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