If you’re an old head like me then you grew up in the cassette era. They were the CDs back in the day and almost all radios were optimized to only run and support cassette tapes.
Why am I telling you all this?
I recently ran across a question in an audio production forum that pretty much brought me a lot of memories.
I’m going to discuss and provide the solution to this question so I help someone out there that still uses a cassette player to play music.
With that said let’s get right into the post.
Why does my cassette player keep eating my tapes?
The main reason why your cassette player keeps eating your tapes is because the capstan mechanism in your player is sticky due to the build up of tape residue. As time passes, your cassette tape can become sticky because the oxide on the tape naturally and gradually sheds, and added moisture from the air will cause your tape to get sticky residue. This residue will then stick to the pinch roller causing your tape to get stuck and get eaten.
How a pinch roller works
A pinch roller is pretty much a rubberized, free-spinning wheel that is commonly used to press magnetic tape against what is known as a capstan shaft in order to create the friction that is necessary to drive the tape along the magnetic heads (i.e. erase, write, read).
Most standard magnetic tape recorders utilize a single capstan motor and a pinch roller located after the magnetic heads in the direction of the moving tape.
However multiple pinch rollers may also be used in association with one or more capstans.
A good example of the application of multiple pinch rollers is the Technics RS-1520 tape recorder, which basically uses two pinch rollers that are located on opposite sides of a single capstan shaft, providing stable transport across the two sets of magnetic heads.
Dual pinch rollers are also used rightly along with dual capstans in auto-reverse cassette decks to drive the tape in both directions as needed. In this case, only one pinch roller is pressed against its corresponding capstan at a given time.
The Capstan
The capstan is a rotating spindle that is used to move recording tape through the working mechanism of a tape recorder.
The tape is threaded between the capstan and one or more wheels that are covered with rubbers, they are called pinch rollers, their role is to press against the capstan, therefore providing the friction necessary for the capstan to pull the tape.
The capstan is always placed in the direction of tape motion which is downstream from the tape heads.
In order to maintain the required tension against the tape heads and other parts of the tape transport, a small amount of drag is placed on the supply reel.
Tape recorder capstans have a function that is similar to nautical capstans, which however have no pinch rollers, the line simply being wound around them.
The basic use of a capstan allows the tape to run at a very precise and constant speed. Capstans are high precision-machined spindles, polished very smooth: any out-of-roundness or imperfections can cause uneven motion and an audible effect called the “flutter”.
The alternative to the capstan drive is simply driving the tape takeup reel (which was used on some cheap tape recorders), causes problems both with the speed difference between a full and empty reel and with speed variations as described.
Dual capstans, where one is on each side of the heads, are claimed to provide even smoother tape travel across the heads and result in less variance in the recorded/playback signal.
Trouble shooting
Below are some things you should do to avoid your cassette being eaten:
1. Ensure that the proper type of cassette tape is being used because some cassette players are not really compatible with some types of tapes.
2. You should egularly clean the tape heads using a dry head-cleaning cassette tape. This will help you avoid any build up.
3. Some players are not optmized to play longer tapes so try to playback a tape that is shorter in length.
4. Lastly, Depending on the location of your unit, the tape heads may have condensation on them. Therefore Open up the tape door, unplug the unit and let the unit sit for like an hour so the moisture can dry up. Then plug the unit back in and try to play the tape again.
Cleaning your pinch roller
Most audiophiles will advise you to use denature alcohol to clean up the pinch roller.
This breaks down the dirt much better than traditional soap and water.
Water does not dissolve the tape oxide or polymers of tape in any way so it’s not something I’d really recommend.
Denatured alcohol will clean the roller the best.
Pinch Roller rejuvenation?
I don’t really recommend any pinch roller rejuvenation techniques.
The best form of repair for the pinch roller is simply replacement. Before you ask…. NO, it’s not expensive. It quiet low cost.
Trying to repair the one you have is a waste of time and won’t yield any good results. Plus, new pinch rollers are available in many sizes. All you have to do is simply measure the old one and do a search.
In most cases, you can’t replace it with the original, exact manufacturers part (since it’s no longer available). However you can find some pretty good ones that can get the job done.
