Microcassette information

Launched in 1969 as a storage medium for spoken text (dictation) in portable recorders, answering machines and to a small extent as a (digital) data cassette for computer systems. Although nowadays largely replaced by digital data storage, the microcassette has another failed purpose that is lesser known, its use as a storage medium for music.

Below is information about the operation of the microcassette, the sound quality, how to make recordings, light maintenance of the machines and the major requirements that are imposed when purchasing and starting with this type of medium.

  1. How does a microcassette work?
  2. Types of tape and quality.
  3. Devices for playback and recording.
  4. How to make recordings?
  5. Maintenance and adjustments.
  6. Buying players/recorders.
  7. Buying microcassettes.
  8. Inlay cards and stickers.

I often use the Compact cassette as a reference on this page, so it is advisable to read the information page of the Compact cassette first to get a clearer picture of the micro cassette.

1. How does a microcassette work?

Just like the normal cassette, the microcassette also works with tape, the tape width is the same as that of the compact cassette, with the biggest difference being the size of the housing and parts that handle the transport of the tape. Let's put the two formats side by side and look at their operation and differences in detail.

Here a normal cassette (right) next to a microcassette (left) the name 'micro' speaks for itself. At first glance, there are few other noticeable differences other than the size, as the operation is largely the same, except for a few striking details.

With the compact cassette, the tape runs from left to right when playing (made clear by the red arrow). In this case, the tape is ready for use with the A side facing us (as shown by the green arrow).

With a microcassette it is the other way around, the tape runs from right to left (red arrow) and the cassette is also ready with the A side facing us (green arrow). An arrow is also printed in the middle of the sticker itself to make the playback direction clear to the user.

The compact cassette has two tabs on top that serve as overwrite protection. They are still present on this cassette, if I were to break out these two tabs the cassette is protected against overwriting for both sides.

The microcassette also has the same type of security, the big difference being that the tabs are on the sides of the cassette. The operation is otherwise the same, when you break out the tab you protect the cassette against being overwritten. If you scroll back up you will see that above the letter A on the microcassette an arrow points to this particular side. The security tab for the side in front of you is therefore always on the right side of the microcassette.

For the transport of the tape, we look at the microcassette in combination with a portable player/recorder.

The position of the erase/read/record head.
The position of the Pinch Roller.
The Capstan runs through an opening in the cassette.
These plastic pins serve purely to keep the cassette stable during playback/recording.

If necessary, click on the photos above for a better view.

The parts on a microcassette player/recorder are almost the same as on a compact cassette, the biggest difference is the size and a difference in the location of the parts as can be clearly seen below.

Here are the differences between a compact cassette recorder and a microcassette recorder side by side. The parts are mirrored, which is understandable considering that the playback direction is also reversed for both media. You can now clearly see that the position of the parts is also different. The compact cassette recorder has an erasing head in the form of a so-called permanent magnet (indicated by the blue arrow), the microcassette recorder does not have this, as the erasing head is (as far as I have been able to discover) is built into the read/record head (red arrow).

Speed controls on portable recorders.
Speed controls on portable recorders.

Another important detail that should not be forgotten is that many microcassette players and recorders can record and playback at two different speeds.

The compact cassette plays at a fixed speed of 4,76 cm per second. A microcassette plays at about half this speed at 2.4 centimeters per second.
But it is also possible to halve this speed to 1,2 centimeters per second.

Setting the speed to 1,2cm/s has the advantage that the total recording time of a cassette doubles.*
The disadvantage, on the other hand, is that the quality of a recording also deteriorates sharply.

Why is this option available on the microcassette but not on the compact cassette?
The main reason that a microcassette has this option is because it is originally used purely for dictation (recording spoken text), although the quality deteriorates sharply at a lower speed, it makes little difference with voice recordings, as long as you can hear what is being said you're fine.

Although the compact cassette was originally also used for dictation, this function later mostly shifted to the preference for recording music, in order to maintain good quality it is therefore important that you use the highest playback speed.

It should be noted that a dictation machine for the compact cassette often still has a speed control, although this can usually be set freely and you are not tied to predetermined speeds.

* In fact, it is not so much a doubling of playing time because 1,2cm/s is the 'normal' speed for the microcassette, more information about this is given below.

The total recording time (for both sides) is generally always indicated on the cassette, shown here by the number "60" which means the number of minutes. The time is based on the speed of 1.2 cm/s. So if you set the speed to 2.4 cm/s, this means that the total playing time of this cassette is halved. This 60 minute cassette therefore only has 30 minutes of playing time at 2.4 cm/s.

Since a cassette always has two sides, this means that you have to divide the total playing time by two. You then arrive at the following playing times with the above cassette:

For 1,2 cm/s you have 30 minutes of recording time per side (60 minutes in total).
For 2,4 cm/s you only have 15 minutes of recording time per side (30 minutes total).

Although it is not indicated on the cassette itself, it is generally accepted that the indicated playing time on a cassette refers to a speed of 1,2cm/s instead of 2,4cm/s.

Above is a short video of recording and playback at both speeds. The difference in speed and quality is clearly noticeable, the most striking thing is that the volume is noticeably lower at a lower speed. The latter can be compensated by turning up the volume before recording. Yet both speeds succeed in their goal, a clearly audible voice recording, provided you play it back at the correct speed of course.

Finally, it is interesting to mention that the microcassette (released in 1969) was not actually the first medium of its format, to the right of the microcassette is the mini-cassette, this medium (with the same purpose) was actually released two years earlier (in 1967) and looks exactly like its later counterpart. In fact, both formats were competitors to each other. But actually there was never a case of fierce competition between the two. Both mediums have remained popular when it comes to dictation, both with their own advantages and disadvantages. Nevertheless, you could state that the microcassette was more popular and used more often than the mini-cassette.

Because the two are very similar, they are sometimes confused with each other. To recognize the difference in both cassettes, it is best to look at the spool, the teeth are closer together on a mini-cassette than on the microcassette. You can of course also look at the inscription, the names of the mediums are usually written on the cassette itself.

2. Types of tapes and quality.

The microcassette comes in different types of tapes, playback length and quality, although the latter is somewhat more limited compared to the compact cassette. Let's take a look at the main differences.

First of all, there is the total playing time of the cassettes. This can vary quite a bit depending on the purpose.
At a glance, the following playing times are available (some more common than others):

  • MC-10
  • MC-15
  • MC-20
  • MC-30
  • MC-46
  • MC-60
  • MC-90

Again, this concerns the playback time if you maintain a speed of 1,2 cm/s. The playing time is of course halved if you set the speed to 2,4 cm/s.

The most common playback lengths are mainly 60 and 90 minutes. There is a small but important detail to mention about these two lengths:

Here are two microcassettes from the Panasonic brand, one has a playing time of 60 minutes, the other has a playing time of 90. Can you see the difference? The thickness of the tape is different. To get 90 minutes on a microcassette, the tape is made thinner, so thin even that it is partially transparent. This also means that the 90 minute cassette is more susceptible to damage.

In addition to the length, the microcassette has two different tape compositions. The most common is the standard tape, which consists of a Ferro coating. Although this composition is often called 'type I' for the compact cassette, no type designation is known for the microcassette.
In the case of Ferro, this is usually referred to as "Normal Position", although more often there is no type designation at all.

In addition, there is the tape with a Metal coating (this is also referred to as 'type IV' for the compact cassette). This type of tape is much better at capturing sound than Ferro and therefore retains much better quality during recording and playback. In the case of a Metal cassette, it is almost always clearly stated on the cassette, partly because this composition is of way better quality.

In short, you have "Normal Position" and "Metal" as the type designation for the microcassette.

The difference between the two is best seen in the tape itself, Ferro is brown in color where Metal is black.

Metal tape is an exceptional case for the microcassette, the purpose of use of this type of cassette is also different from the standard. Due to its exceptional sound quality, this type of cassette can be used for recording music, provided with the right equipment.

Finally, it is extremely difficult to find a microcassette with Metal tape, the numbers produced are very small compared to the Ferro variant, partly because a microcassette has almost never been seriously used to record music.

The Metal cassette is so exceptional that its appearance sometimes also looks more interesting. Unfortunately for this case, it is also very susceptible to fingerprints...

To add, because Metal cassettes are so rare, switching between the two compositions is not even an option on most players and recorders. Only devices specifically designed to play Metal tape have this function.

In addition to different types of tape, there are also cassettes for other purposes. Above, for example, a cassette intended for cleaning the heads of a playback device.

The cassette also comes with a information card with instructions on how to use it.

Images source: Ebay

There are also special cassettes for adjusting a playback device. The top one is a test tone cassette to measure deviations in speed, the lower two cassettes are mainly to look at the torque of a device. These types of cassettes are very rare and expensive.

Finally, the cassettes usually come with an accompanying box, of which there are different versions as can be clearly seen above. Sometimes they even come as a pack of two or four. But the purpose remains the same, the box protects the cassette against external influences.

3. Devices for playback and recording.

Although we have already seen something about a playback and recording device in the previous chapters, here we'll go into more detail about the machines that have been on the market, there are some special details and purposes for which some device can be used.

Above are four devices, each with its own unique properties and purposes. We go through them one by one and look at the many options they offer.

We start with the standard dictation machine in this case a Sony M-430, which is clearly made to be used on the road. A compact device where the buttons are placed in such a way that you can operate most parts with only one hand.

The controls for the cassette are on the side, here are the buttons for recording, playing and stopping/ejecting the cassette. The connection for headphones and volume control are located on the top, and on the far right there's a built-in microphone for recording. Finally, on the other side there is an option for speed and a connection for an external power supply, the machine also runs on batteries (2 AA batteries to be precise).

Above is a short (far from serious) demonstration of how this device works.

In addition, we have a similar device, only more compact than the previous one, the Sony M-909. It is often said that this is the world's smallest "Walkman", but appearances can be deceiving, this is no Walkman but nothing other than an ordinary dictation machine which is indeed very small.

The controls are again on the side, although they are less easy to operate compared to it's cousin shown before. It is striking however that this device has an 'auto reverse' option. At the end of the tape, it reverses the playback direction by itself so you don't have to physically turn the tape over.

There are two switches for the microphone on the back. This recorder also has a built-in microphone, but also has a connection for an external microphone which can be selected with the bottom switch. The top switch is for the microphone sensitivity. At the bottom left you will see a wheel with numbers, this is the volume control.

The other side contains a shared connection for headphones but can also be used for the external microphone. Below you can see the built-in microphone itself, recognizable by the small grille. The switch next to it is special, it says VOR underneath which is an abbreviation for "Voice Operated Recording". In short, this device can automatically record when it picks up sound. This switch can be used to enable or disable the relevant function. Furthermore, on the right we see the volume control again with a small light next to it to indicate whether the device is recording or what the status of the battery is. (By the way, this recorder is powered by a single AAA battery).

Finally, you have the other side, here you see the battery cover, underneath is a switch for the speed control, and on the far right the button to open the door.

Now we've arrived at the more special devices, here you see the Philips D8000 "Stereo Radio Micro Cassette Recorder" (a mouthful). The name speaks for itself, it is essentially a small boombox that uses microcassettes instead of the normal compact cassette.

This device also has volume controls, but besides pure volume it also has a balance control (left or right) and a pitch control. Below the controls themself is a wide button that serves as a snooze button.

In the middle you see the controls for the cassette, with all necessary functions from winding and playing to recording and ejecting.

On the far right there are some additional switches to choose between the radio and the player, as well as functions such as a pause switch for the cassette and a mono/stereo switch. (On the right side there is also a dial for the radio frequency).

The left side hides a function that was already partially revealed with the snooze button. Although it is not mentioned in the long name itself. This device also functions as an alarm clock, the functions dial at the top left is used to display things on the screen which is located on the front, with which you can choose between a tape counter, general time, alarm time, alarm clock setting and time setting.

On the right is a switch for the alarm clock itself, which has 3 positions, off, audio (via radio or cassette) and lastly a simple buzzer. Finally, on the bottom left we see a set of connections for an external stereo sound source, the external power supply and a connection for headphones at the bottom.

The device itself runs on a special set of batteries. 4 AA batteries for the cassette deck and radio. And a small CR 2032 to keep track of the time, alarm and other functions on the display.

On the back we find the last options, including speed control and a special switch called RIF with 1 or 2 respectively. This function is only used if you want to record sound from the AM radio. If necessary, this switch reduces noise that may be audible on an AM broadcast.

Before we move on to the last device, there is one last thing to tell about, why would you make a boombox that uses microcassettes as a sound medium? It looks like you can use a microcassette to specifically play back music through the device. Something that I have already partially described as a possibility in the previous chapters.

The microcassette has actually never been seriously used as a music medium, but attempts have been made to use it for this purpose. After all, this becomes clear when we look at the last device.

Here is a final demonstration of the device in working condition. After all, I had to repair it before I could use the cassette player/recorder.

Finally, we arrive at the most special device in the collection of microcassette players/recorders, the Sanyo RD XM1.

Unlike the previous devices, this one is a big exception and therefore also has many other functions. Starting with Dolby noise reduction, HX to be precise. In addition, two buttons to select between Metal or Ferro tape, furthermore a option for a microphone or external sound source as an input source. On the right the volume control for the input source. On top we see a panel that displays the loudness in decibels.

In the middle of the device we find the cassette holder together with its controls. No further explanation is required here.

On the far left is the tape counter with the rest button and a timer function, with this last function you can choose to have the device record immediately upon start-up if it is supplied with power via an external clock. At the bottom there is a 6.3mm connection for a headphone.

So this device is clearly designed to be used as a player and recording system for music purposes. There is also no speed control, it plays at 2.4cm/s as standard (and therefore lacks the 1.2cm/s option). It is not the only model with this function, but it is one of the happy few. It was an attempt to market the microcassette as the new medium for music, although it was a major failure. The sound quality of the normal cassette was often questionable to start with, and although this deck has all the features to increase the quality, it was not enough to even come close to the sound quality of a normal cassette.

Nevertheless, it is actually possible to record and play music with decent quality, provided you use the best options. Dolby HX and microcassettes with Metal tape.

here's a demonstration of the device in operation, the sound you hear is not the best example as I am using a cheap external speaker.

At the time of writing this the device is not yet ready for use, I have been working on it for three years (on and off) to get it working, spare parts are not available and the components inside are so small that a repair is not easy, above a video of what it sounds like in its worst 'working' state.

4. How to make recordings?

With the previous chapters done, it's time for the real work, making your own recording.

We assume that this is going to be a music recording. Dictating is as simple as pressing the record button and speaking into the microphone, but making a recording with music is a little bit more complicated!

For this chapter we use the Sanyo RD XM as our recording device.

The first thing to determine is what device we want to use as a source. As with other media and information pages I have described, my preference is a digital source.

As you can see above, I have all the media I work with neatly organized, in the relevant folders we find the prepared playlists themselves.

Of course, you can use any other audio source for this instruction, whether it is a record player, the radio or perhaps another analog source, it doesn't matter. Personally, I can say that using a digital source is preferable as the base must be able to deliver the highest possible quality so that the tape loses as little quality as possible during recording.

If you choose the same source as I do, it may be useful to show how I work in advance. After all, preparing a playlist takes up most of the time, recording itself is probably the easiest part.

Here's an image of how I organize my playlists inside the microcassette folder in 2023. Each folder contains its own list of songs. The lists that are ready for recording are adjusted to show a red check mark icon. If a recording is done and has succeeded the play test I change it again into a green check mark. This way I maintain an nice overview and can see at one glance the current status of every playlists (the lists with a normal folder icon are not ready yet).

At the bottom of the image you see various audio files and Excel files. These are not required for making a recording but certainly have a functional purpose in my case. The audio files are the so-called in- and outros of a playlist. I mainly use this because the beginning of the tape in a cassette sometimes contains defects, the beginning can be dull, have pops or you may have 'drop-outs'. Usually this problem disappears after a few seconds. The intro is used to cover this first part. The outro is purely to indicate that a cassette has ended. Finally, for me the Excel file is the overview of a playlist, let's take a look at an example playlist.

For the curious reader, the folder with the forbidden icon contains old playlists, these playlists were created with a notepad, I keep them for in case I ever have to recreate them.

Above is an example of a relevant playlist and its associated Excel file with the information. As you can see, I have adjusted the song titles so they line up with the way I want to record them. A microcassette often has little playing time, so the playlist itself is also quite short.

I enter the necessary information in the Excel file when making the playlist, which type of tape, which recording medium, the playing time of the tape, whether I use noise reduction and finally the titles of the songs and their playing time. The Excel file itself calculates the time per side, what has been used and what I have left. The results appear in the dark gray box on the right.

If you want to use the Excel file yourself, you can download the file at the bottom of the relevant page for your own use.

In my case everything is ready to go, I don't use the computer itself as a audio source, but first copy the files to a media center, this box is perfect for streaming audio files without a loss of quality.

From experience I have noticed that the computer is unsuited as a source. After all, the computer housing becomes statically charged during prolonged use. This may result in a deep hum being heard in the recording, something you want to avoid at all costs!

We are not finished with the preparation yet, but we shift our attention to the physical work.

First we determine which type of tape we want to use as the carrier for the music. Although I have described in the previous chapters that Metal is the perfect option for music recordings, a Ferro tape certainly also be used for this purpose. The only big difference is that a Ferro tape contains noticeably more noise compared to a Metal tape.

It is therefore preferable to use a Metal tape, but if the music itself is 'heavy' enough, a Ferro tape is als suited, as noise is mainly present on quieter parts or with treble (high tones). So Ferro remains a choice if your music contains a lot of bass (low tones).

Let's say that if you mainly want to record rock or metal (metal is in the music genre), a Ferro tape will perform just as well (or according to some even better) than a Metal tape. If you want to record calmer music such as classical or, in my case, a combination of both, Metal tape may be preferable in that case.

With the choice set on Metal tape, we can place it in the device, but not before removing any slack from the tape. Anyone who has worked with cassettes before knows that this is a normal step in the process. With the microcassette this step is certainly a requirement, the tape tends to unwind even faster with a microcassette if you have not used it for a while, as can be clearly seen in the first image. You can even read something about this in the manual of the Sanyo recorder.

The image in the manual exaggerates the concept of removing slack a lot, if the tape sticks out that far from the housing you have clearly done something wrong! The next step is already being indicated, but we have to wait just a little longer! (Or at least that's the case for me).

This device (from 1981) is almost 40 years old in 2023, so the reels may become a stiff if the device has been turned off for a while. For me this is especially the case with the left reel. I turn on the device and press the fast forward button. I let the device run like this for about 10 minutes so that it can literally warm up. If I skip this step, the deck will pull the tape out of the cassette and grind it to pieces!

While the deck is warming up we check the settings, I set it to Metal and also choose the noise reduction. The latter has caused quite a few discussions though, do you use noise reduction or not? It is a difficult question to answer because tastes differ greatly!

Personally, I tend to use noise reduction less often then before. When using this, the noise threshold is increased (so you have less noise), but on the other side the frequency of the music is also negatively affected. In most cases I just take the noise for granted and ignore Dolby all together.

Yet in practice things are slightly different here. The microcassette as a medium is actually not suitable for recording music at all, even with a metal tape noise is still very much prevalent, so much so that it is really a disturbing factor. In addition, most normal cassette decks mainly have Dolby B. This deck has one of the most modern noise reduction on the market (namely Dolby HX). It doesn't matter whether you go for Ferro or Metal, in both cases you definitely want to use this function when working with microcassettes!

It is also important to mention that Dolby B is required in both recording and playback (the latter only when you also used it while recording). Dolby HX is different, you only use it when recording and no longer need it when playing!

If this is not enough information, I have written an extensive blog that goes into depth about noise reduction, you can read all about it here.

The deck is warmed up and ready for use! The cassette can be inserted into the device, to record we first put the device in pause mode. After this we press the Record button and the Play button respectively one after the other. The device is now ready for recording, but before we start we first determine the volume level for each song.

I start playing the music on the source, the display shows the volume level. I adjust the volume knob so that the highest parts of each song do not exceed the Dolby logo (the 4th red dot seen from the left). I write the levels down on a post-it. After this I go to the next song and repeat the process.

With the list completed, we are finally ready for the actual recording!

But another 'small' point that is worth mentioning here as the following question:

Do you actually have to determine the volume level for each song? Yes and no...

No: In fact, setting the level to the loudest song in the entire list would be enough.
It is especially important that the sound level does not exceed the upper limit. Everything below this is theoretically no problem (although there is a greater chance that you will hear more noise in the quietest parts).

Yes: because as you can see, the level can vary considerably per song. One song is louder than the other. If I set the volume control to its lowest setting (3.5) for all songs, the songs with a high value would be much quieter than the rest. This results in more noise at the relevant songs with a normally high value. If all songs are close to each other in terms of their respected limit, you could still choose a low average level. As you can see above, most are at 3.5 with one song going for 4.5. The two songs with a value of 7 and 6.5 are just the intros and not very important in this case.

Both have their advantages and disadvantages. If you give each song its own level, you will have to adjust the volume every time during recording when the next song starts with a different value. If you choose a fixed low average, you only have to adjust the volume control once and you can start recording immediately. After this, you don't actually have to do anything until the recording is completed. In the meantime you can do something else, clean the house, do the laundry, to name a few.

I aim for perfection and therefore choose to set the level for each song separately.
Moreover, I get more satisfaction from a recording if I put more effort into it, a finished tape feels more valuable when you have put so much time and effort into it!

With all the above steps done, we can finally start recording for real this time! I first start the deck by pressing the pause button again and start the audio source immediately afterwards. Finally, I check that both reels are spinning to make sure it isn't eating the tape. As mentioned earlier, most of the work is already done. I only keep an eye on the device to adjust the volume level, but sometimes also check whether everything is still going well. Again, this device is almost 40 years old and had to be thoroughly repaired before it could be used at all. I only trust such a device even a little if I have been able to take several recordings without any problems.

After each song I scratch it off the list, if the subsequent songs are at the same level (and I trust the device) I let it do its thing unattended and focus myself on some chores (after all, there is always something to do around the house).

We are halfway through, the recording of side A has been completed and the device has stopped automatically at the end. We turn the tape over but check it again to see if there is any slack in the tape! After this we repeat the previous steps, put the device in pause mode and press 'record' and 'play'. I press the pause button again after which recording starts and I start the audio source right afterwards.

I check again whether both reels are turning and let the device do its thing again.

I could write another whole story here, but things speaks for itself now, I still have some laundry to do, so I will continue with that. I don't have to adjust the volume for the rest of the playlist, every now and then I get back to see if my tape hasn't been eaten yet...

We are finished! The evening has fallen and the recording has been completed. But we're still not there! What remains is the listening test, (for the experts among us) this deck does not have a separate playback head. This means that while recording I cannot hear whether the recording on the tape actually sounds good (i.e. I only hear the sound of the audio source). I will do the listening test another time. I'll make dinner first and spend the rest of the evening checking for typos and errors in the chapter I just wrote.

In total (compiling the playlist, filling in the Excel file, preparing the recording and actually recording the music) it took me about 3 hours to fill this tape with music. The listening test will also take around an hour and if the recording is actually successful, I will take some extra time to make a card to put in the box of the cassette. I will describe the latter in Chapter 8 (Inlay cards & stickers).

The total time I needed to make this tape will ultimately amount to a rough 6 hours, because I want to do the inlay card properly which also takes a lot of time.

Ultimately, you can of course decide for yourself how much time you actually want to put into a recording. Once again I'm going for the perfect picture. If you don't feel like copying everything above, you can theoretically do a recording in less than 2 hours!

[place image of cassette with box and card here]

And so I can add my first home made recorded microcassette to the collection, eventually this collection will also grow as I make more recordings, as you may have seen before, I have a number of playlists in queue.

If you are going to dive into the world of microcassette recording yourself, then I wish you the best of luck and maybe the information I have provided in this chapter is useful to you!