April 17, 2017 - John HadfieldTape Residue and Good Playback
An unexpected problem with aging cassette tapes.
When cassette tapes played poorly three decades ago, people often looked to the cassette player as the problem. And frequently the player was the culprit. There were numerous common problems with cassette players involving the play head, the erase head, the capstan, the pinch roller, etc. But now that we are dealing with aging cassette tapes, there are a host of other issues that can cause poor playback. These new problems are related to the cassette itself, not the player.
One of the more interesting problems is the residual buildup on the posts and contact areas in the cassette housing.
The older a cassette tape is, the more likely it is to shed or flake. And when you consider all of the different spots that the tape touches, you can begin to see a problem. The photo above shows a common example of what happens inside the tape housing as the tape begins to flake and shed.
Inside the cassette housing, the tape makes contact in several spots, and as it drags across these different points, the aging tape tends to flake off and create build up. When the tape is first manufactured, these different spots are very smooth so the tape can pass across them with minimal drag, but as this buildup begins, these contact areas begin to get sticky. As a result, the pinch roller and capstan have to work harder to move the tape. If it becomes excessive, this additional drag on the cassette can actually cause the tape to play poorly.
Some cassettes age better than others, but eventually all tapes will fall victim to the issue of flaking and shedding.
A little rubbing alcohol and a q-tip and you can remove the residue. But eventually the problem will come back. If the tape is shedding, it will continue to shed and eventually the sound itself will suffer. This is why it's a good idea to digitize tapes now rather than waiting. Digitizing your tapes gives you the peace of mind of having a permanent archive before it deteriorates any further.