Audio Cassette Loop




About: My name is Randy and I am a Community Manager in these here parts. In a previous life I had founded and run the Instructables Design Studio (RIP) @ Autodesk's Pier 9 Technology Center. I'm also the author ...

Theoretically it sounds really easy; you can make a tape loop by taping the ends of a short piece of magnetic ribbon together and sticking it back inside the cassette tape. However, if you ever actually tried to do this, you will soon realize that it is a tad bit trickier than one would think. I spent an afternoon working out and refining this science. After many tries and many, throw-my-hands-in-the-air-and-promise-to-give-up sorts of moments, I think I have it down reasonably enough to write instructions for someone else to do it. Now you too can tape the ends of magnetic ribbon together, ?, and profit!

Step 1: Go Get Stuff

You will need:

A cassette
A rubber washer
A razor or craft knife
Double-sided tape
Clear packing tape
A screwdriver
Mat board
A ruler
A cassette player

Step 2: Open the Case

Open the cassette tape by removing the screws. Carefully set them aside for later reassembly.

Step 3: Remove the Reels

Remove the tape reels, but don't disturb any of the other mechanisms.

Step 4: Prepare the Reels

Cut both reels free from the magnetic tape.

Put your rubber washer around one of them. This will be the wheel which will pull the tape.

Step 5: Cut Some Magnetic Tape

Cut a section of magnetic tape roughly a foot long.

Step 6: Thread

Position your wheels back inside the tape and thread the magnetic ribbon around the rubber wheel, under the unmodified wheel, around the pulley opposite the rubber wheel, through the channel at the bottom of the tape, around the other pulley and also to the right of the plastic peg (next to the pulley).

In other words, just look at the pictures.

Step 7: Tape

Apply a small piece of double-sided tape on the inside of the magnetic ribbon, pull the loop tight and tape it evenly together.

If the magnetic ribbon is attached at an angle or any tape is sticking off the sides, your tape loop almost assuredly will not work.

Step 8: Washer

Cut a washer out of mat board and stick it on the inside of the case around the opening that lines up with the wheel with the rubber on it.

This provides more pressure on the sides of the wheel and ensures the wheel will spin. I found this to be necessary.

Step 9: Close the Case

Trim away all excess magnet ribbon and close the cassette back up. When reinserting the screws, only tighten them about 80% on the side with the rubber wheel. Readjust tightness as necessary until it plays correctly in your cassette deck.

Step 10: Now Make It Better

Perhaps that first loop you made was a little glitchy and you would like for it to work better.

There is an easy way to do this.

First, reopen the case, remove the magnetic ribbon loop and cut it in half anywhere along its length.

Step 11: Make a New Piece

Carefully measure this piece of magnetic ribbon and then cut yet another piece of that exact length.

Step 12: Splice

Take a small piece of packing tape and evenly splice together the two ends to form a solid band (without any twists in it... although, if you put one twist in it, it will double the length of the loop, but make it harder to reassemble).

Trim away any excess packing tape with your razor or craft knife.

Step 13: Putting All Back Together Again

Install the new band of magnetic tape into the cassette deck.

Reassemble the whole unit once more and enjoy your cleaner sounding tape loop.

The trick:
I always assumed that the tape wheel was the mechanism feeding the tape through the player and because of this, I thought that the magnetic ribbon had to be highly tensioned and the wheel needed to be as loose as possible to spin freely. However, what I discovered is that what is really feeding the magnetic ribbon through the player is a little rubber wheel that comes up from the bottom when you hit play. Because of this, it is beneficial if the ribbon has a little slack (less tensioned) and the wheel is a little compressed with sides of the case. Figuring out the right ratio takes a little trial and error.

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87 Discussions


Answer 8 days ago

I do not recall and the tape is long gone. I know I bought assorted rubber washers in the plumbing section at Ace Hardware. The inner diameter of the washer should be large enough to go around the cassette wheel (obviously). I think the washer typically fits inside of faucets (if that is any help).


1 year ago

This is hilarious! At least for some ideas I have. I never even knew existed. Thank you!


2 years ago

Did you know you can just buy endless loop cassettes? TDK made them for one, I have a couple.

1 reply

you know, i know this guy and back in the 80s-90-s, he made like a millions of these. he stole and bought and whatevered millions of tape players, walkmans and stuff, and he removed the heads. on each loop he recorded a different tone (sneak to the church, every day 6-7 tones before they caught him, later he used this older guy's hammond) and he used his parent's upright piano (actually destroyed it!) and he made this tape-organ-like-instrument, and it worked great! (well, actually, not that great, because the motor speed went up & down, changing the pitch [not too much anyway;it was playable], and the difference between church organ on lower octaves and hammond on higher octaves can be clearly seen, and tape it wastes over time [you elder guys know what i'm talking about hahaha!]). and this instrument is still alive today, although some of the tapes have snapped and all of them are wasted...

Somebody around here should do this. Really.


4 years ago on Introduction

Excellent Instructable! Here is a suggestion for modification to get longer recording time. With a 1" more or less tail extending out of the center of the take-up hub, loosely wind the length of tape you require i.e. 1 second = 1.875 inches of tape. (Thus, if you want a 1 minute continuous loop 60 sec here is the math. 60 x 1.875 = 112.5 inches or 9.375 feet of tape.) Then thread the tape from the inside of the spool as shown in the Instructable. Then make your splice to the end piece winding on the outside and VOILA, endless loop tape for your time needs. Here is a link showing a pic of an endless loop cassette with 12 minutes of time on it. Hope this helps, enjoy.

12 minute loop tape.JPG
6 replies

Reply 3 years ago on Introduction

Foxtrot70, could you please elaborate on how to get the inside part of the tape to come out smothly? I tried it a few times and each time the outside part of the tape would tighten up around the inside, and the inside part would have difficulty turning and end up breaking or stretching....


Reply 3 years ago on Introduction

This is rather interesting. Yesterday I got a request to make an audio recording on endless loop cassette tape. Searching Ebay and else where these tapes seem to be no longer available. This is going to force me to make an Instructable to post.


Reply 3 years ago on Introduction

mmiller6 - If the Ebay link does not work this, 271984532700, is the item number for the endless loop tape just past the number into the search box in Ebay, then, press ENTER or click on SEARCH at the Ebay box.


Reply 3 years ago on Introduction

mmillere6 - With a longer time of tape winding on to the outside and feeding out the center a slightly different spindle is required. The take-up spindle must be an inverted cone shape to allow the tape to slide UP out of the center of the take-up as the spindle turns. A vertical sided reel of a standard cassette case will have too much friction and bind as you are experiencing. Here is a current link to Ebay for a single blank if more play time were required cutting, splicing, then adding the required length would do the trick. If you were wanting to make more tapes you could disassemble this one and make a mold casting of the spindle to modify a standard cassette. I hope this helps you, good luck.

Here is the link:


8 years ago on Introduction

So I was playing around with this a bit yesterday and I've been having a lot of fun figuring things out. I might even write my own Instructable to expand a bit (if you don't mind).

First off, the washer and matboard seem to be pretty unnecessary, in fact I've had success just wrapping the tape around the little wheels at the bottom to make it much shorter, or around the little clear plastic pegs throughout the cassette (the one I used had 6). I also made one with the tape wrapped around both the reels and with that one I was able to fast forward or rewind for superfast playback.

The Mobeius tape loop worked out alright, but it was not super practical. Half of it plays back regularly and half plays whatever is on the other side of the tape, but in reverse and more quietly. Also, I was only able to record over the 'regular' side, and had to flip it over and time it just right to record over the other half.

You can still use both sides of the tape.

It seems like cutting the tape at an angle and taping it carefully will give a really clean loop, but whenever I try to record a drone over the whole thing, I get a bit of silence, presumable from the distance between the bit of the tape machine that erases and the bit that records when I press stop. This can be overcome by either using a pre-recorded tape or by recording a loop and then shortening it (though so far I've been too lazy to try the second option).

It is possible to make a microcasette loop, but it is a total pain to do and isn't much quicker than a cassette loop (since the tape speed is slower). Basically the tape has to be really snug and the tape is more delicate so you can't handle it too much (I wore a blue plastic glove and used tweezers).

2 replies

Reply 4 years ago on Introduction

Actually you are correct in that you should be cutting the tape at an angle because it acts as a cross-fade, and the silence is most likely coming from metal (or magnetized) cutting tools. Since a cassette tape is a magnetic tape, if you cut it with something magnetic it can ruin the tapes ability to become re-magnetized (so to speak) properly later. One thing to remember with this is plastic works much better than metal for cutting and placing if possible.


Reply 8 years ago on Introduction

You should totally post your own Instructable showing what you have found. I would be interested in seeing instructions for all of your different experiments. I would have not thought the Mobeius tape loop would have worked like that. One of these days I want to get back to messing around with this to try to make a seamless loop.


Reply 7 years ago on Introduction

Place near your parrot before you go to work with it repeating "Help, somebody changed me into a parrot!".


Reply 5 years ago on Introduction

No need, just repeat that sentence to your parrot a few times and he/she will do it all by his/her self!


Reply 8 years ago on Introduction

One use (apart from old answeringmachines) is in making a Mellotron