Vinyl, Cassette, CD, MiniDisc, MP3 & Co.

In this article I tell the story and describe the functioning of the media and formats for recording and reproducing music, which I have experimented with and been passionate about, not aiming at covering the full range of technologies that have come on the commercial market, nor at delving into them in detail.

The vinyl records

In December 1877, Thomas Alva Edison invented the phonograph, the ancestor of the turntable and the record player, like my parents’ red and white one, produced by Lesa, with which I listened to the first singles as a child, among which I remember “A Whiter Shade of Pale” by Procol Harum (Gary Brooker, who passed away in the days when I am writing this article, may rest in peace), “California Dreamin’” in the version made famous by The Mamas & the Papas, “Je t’aime… moi non plus” by Serge Gainsbourg, sung with Jane Birkin, the cover of “The House of the Rising Sun” by The Animals, and many other 45 rpm vinyl records that Mom and Dad had collected in the 1960s and 1970s.

The phonograph records and reproduces, mechanically and analogically, the waveforms of sound vibration by physical variations of a spiral groove.

In Edison’s device, the spiral, or, rather, the helix (from a geometrical viewpoint), was etched by a stylus, set into vibration by sound, on a cylinder covered with tinfoil.

In the 1880s, Alexander Graham Bell (who had shortly before patented the telephone) patented the graphophone, an improved version of Edison’s phonograph, which made use of a wax-covered cardboard cylinder.

The main difference between the phonograph and the graphophone lies in the direction of the engraving: in the former, the stylus produces a groove that varies in depth; in the latter, the stylus engraves the track by zigzagging horizontally.

Shortly before the turn of the 20th century, Emile Berliner replaced the cylinder with a record and patented the gramophone.

During early recordings, which were completely acoustic, sound was picked up by a horn and transmitted by means of tubes to a diaphragm that set the stylus in vibration. In contrast, during playback, the vibration of the stylus, transmitted to the diaphragm, produced the sound coming out of the horn.

This second technique, mutatis mutandis, is the same one on which most modern phono recorders and turntables are based: during recording, a device that works the surface of the record like a lathe, engraves the spiral groove starting at the periphery of the record and ending toward the center, modulating its shape thanks to a transducer that transforms the electrical signal produced by the audio source into the motion of the stylus; during playback, the vibrations of the turntable stylus, produced by contact with changes in the groove, are transformed by the cartridge, a piezoelectric or magnetic transducer, into the electrical signal that is then transmitted to the amplifier.

On a mono record the stylus moves only horizontally, while on a stereo record the stylus also moves vertically. This stereophonic recording and playback system was patented by Alan Blumlein of EMI in 1931. Its name “45/45” summarizes its operation: the two stereo channels are entrusted to the two walls of the groove, each of which moves at 45 degrees to the plane of the record surface, corresponding to the signal level of the channel. During playback, the movement of the needle along the track is detected independently by two transducers each mounted diagonally in front of the respective groove wall.

From the 1920s to the 1950s, the most commonly used material for printing records was a natural resin called shellac, secreted by an insect native to Asia.

Beginning in the 1940s, this was gradually replaced by a vinyl chloride polymer called polyvinyl chloride, or PVC, whose name, in recent years, is used to distinguish vinyl records from other types of records in circulation.

Different types of records are distinguished by their diameter (7, 10, 12 inches), the rotational speed at which they are recorded and played back (33, 45, 78 rpm, omitting decimals), the capacity in terms of the duration of the contents, determined by diameter and rotational speed (among the most popular are “singles,” or SPs, typically 7-inch records recorded at 45 rpm, and long playing, or LPs, 12-inch records recorded at 33 rpm), as well as the quality of recording and playback and the number of audio channels.

Going back to my childhood, I remember a record player that a family friend had purchased during a trip to Japan: a Columbia GP-3 from the early 1980s, also red and white like our record player, however, unlike the record player, not limited to 7-inch records, but able to play 12-inch records as well. My parents’ friend proudly displayed it, hanging on a wall in his study, because it could also work vertically.

As a child I was fascinated by that device to the point that last year, when I found out that the Japanese company Anabas Audio produced a replica, I got myself one, with which I am fully satisfied.

The Anabas Audio GP-N3R, unlike the original Columbia GP-3, is stereo, although the built-in speaker is mono, and is equipped with none other than an Audio-Technica AT3600L cartridge (with ATN3600L stylus). When connected to an external amplifier, it produces respectable sound for a product paid 200 EUR, including shipping. Of course, to the price of the turntable must be added that of a 220- to 110-volt voltage converter or batteries (it requires as many as six D-type, or flashlight, batteries), but satisfying nostalgia is priceless.

Chevelle’s second album “Wonder What’s Next” (2002), pressed on a 12-inch disc recorded at 33 rpm, the classic LP (whose cover is autographed by the Loeffler brothers), played upright on my Anabas Audio GP-N3R precariously balanced on a stack of books.

My family was not into Hi-Fi. At home there was an old piano that Grandpa had given to Mom as a child, on whose yellowed and chipped keys my parallel life as a musician began, but there were no devices capable of reproducing good quality music. It wasn’t until the late 1980s that my brother and I, still students, began composing the first Hi-Fi systems from the proceeds of our extra chores.

In those years, vinyl records, which had also retained the largest market share even when cassettes were mass marketed, were about to be overtaken by compact discs – this is the medium and format that, driven by my passion for computing, I loved and still love more than any other; the numbers of my collection say so: just over a hundred vinyl records and cassettes versus more than two thousand compact discs.

To conclude this first section, the turntable I chose for my most modern system is the Technics SL-1500C, which lacks the nostalgic charm of the Anabas Audio GP-N3R, but is one of the best choices in its market range.

A limited edition of Monolord’s single “I’m staying home” (2021), printed on a 12-inch disc unusually recorded at 45 rpm, decorated by a detail of Michael Hutter’s painting “The Triumph of the Flesh” (evidently inspired by Bosch’s “The Garden of Earthly Delights”) on my Technics SL-1500C.

The cassette

I do not remember on what occasion Grandpa gave me a portable cassette player manufactured by Telefunken, whose model I unfortunately do not remember, which at the time I did not know I could call a boom box.

That first boom box of mine integrated two-way stereo speakers and AM and FM radio receiver whose telescopic antenna, if not retracted and stowed away, got in the way of the carrying handle.

It was not the JVC RC-M90, which went down in history for being immortalized on the cover of LL Cool J’s first album “Radio” (1985), but to my eyes and especially to my ears as a child, it had nothing to envy.

I remember that in 1982, when Mom and Dad gave me my first computer, a Commodore VIC-20, as I did not yet have the Commodore 1530 Datasette, in order to save my programs on cassette, I connected, via an interface ending in a DIN connector, the audio output of my boom box to the VIC-20.

When I later received the Datasette, I struggled quite a lot to find my programs on the cassettes: I had made a note of where I had recorded each program on the tapes by referring to the counter on the boom box, but the one on the Datasette measured the revolutions completely differently. So, I had to resort to the expedient of listening to the tapes to identify the intervals of silence between programs. Thus, when I was seven years old, I learned that the cassette interfaces of computers in those days converted digital data to analog tones and vice versa, just like the modems I discovered years later.

Returning to music, since Fritz Pfleumer invented magnetic tape, as we know it today, for sound recording and playback in 1928, there have been various types of tapes and more and less compact cassettes on the commercial (and professional) market. The most widespread one, with which most of us have experimented, is the one developed by Lou Ottens for Philips and launched on the market in 1963, identified by the registered trademark “compact cassette.”

Although the sale of prerecorded cassettes, often called music cassettes to distinguish them from those sold blank, never exceeded the sale of vinyl, the medium developed by Ottens gained momentum in the 1970s and 1980s and survived into the 1990s because of its portability, and especially because it allowed recording at a very low cost.

I still enjoy extracting audio tracks from concerts posted on YouTube using youtube-dl – I am a subscriber to YouTube Premium, so I commit no crime in doing so – and recording them on cassette with my 1989 Denon DRM-700 or, more often, with my 1993 Denon DRM-740, and then listening to them on headphones with one of my two 1987 Sony WM-DD33 Walkmans, both perfectly restored by my friend Michael Moser at his Walkman Clinic in Vorderthal, Canton Schwyz, Switzerland.

My two 1987 Sony WM-DD33 Walkmans, both perfectly restored by my friend Michael Moser at his Walkman Clinic in Vorderthal, Canton Schwyz, Switzerland.

[Here I had plans to explain how magnetic-tape recording works in compact cassettes and make an honorable mention for DAT and DCC.]

The compact disc

The first CD I bought in 1991 was Seal’s first untitled album.

It does not belong to any of the subgenres of metal and (hard) rock in which I have always been most comfortable, but it shows how beautiful music transcends genres.

The latest CD I found in my mailbox, in the days I am writing this article, is “The Long Road North” (2022), the latest album by Cult of Luna, which has climbed up my list of the best metal albums of the last five years.

The first one bought in a record store, saving on weekly allowances until I put aside those more than thirty thousand liras, invested without knowing if then the money would be well spent, because it was not possible to listen to an album until after buying it. The last one ordered online after having already listened to it several times in high quality streaming.

In thirty-one years, the world has changed, but not my favorite way of listening to music: the love for music and passion for computing of the 16-year-old me were embodied in the compact disc with a perfect marriage and there they remain to this day.

My 1992 Teac CD-P3500 and 1994 Technics SL-PG360A, stolen from my brother, between the CDs of Seal’s first untitled album (1991) and “The Long Road North” (2022) the latest album by Cult of Luna (still wrapped in protective film), respectively the first and the last I have purchased to date. On the open drawer of the Teac, the Mini-CD (8 centimeters in diameter) of Phil Collins’ single “I Wish It Would Rain Down” (1990) in which Eric Clapton plays guitar.

I remember how I tried to explain to my son, when he was in high school, how the process of digitalizing music works. I assumed that it would be easier for him to start with an image, then move to a video, intended as a sequence of images, and finally translate the concept to music. I don’t remember the exact words because my son is now almost twenty-four years old, but I think it went something like this:

«Think of a computer as having to save in a file the information needed to reproduce an image. Lay a grid over the image, which divides it into a number of dots each of which can be of one color only. The finer the grid, the more dots you get and the more faithful the reproduction of the image will be. You know that a computer speaks only the language of numbers and, in particular, those expressed in base-2. So, to indicate the color of each point into which you have divided the image, you need a number large enough to be able to identify all the colors your eyes can see. A friend of yours who knows a lot about the eye and the brain tells you that about sixteen million is a sufficient number. You know that in base-2 for such a large number you need at least 24 digits. So, the file will have to contain 24 bits of information for each point in which you have divided the image. You have made an important choice: you have decided the level of accuracy, or resolution, of the image that the computer will be able to reproduce. Now let’s move on to a video.

«Think of a video as it is imprinted on the film of a movie: a sequence of frames. To play a video, the computer might then save in a file a sequence of images processed as we said before. The frames must flow before our eyes at a sufficient speed for the video to be smooth. Your expert friend tells you that 24 frames per second is enough (it just so happens that the number equals the number of bits from earlier). This is another fundamental concept that adds up to image resolution: consider each frame or image you’ve divided the video into as a sample you’ve collected and call the number of samples you’ve collected each second “sampling frequency”. Frequencies are measured in Hertz, a unit that indicates how many times an event occurs in one second. The sampling frequency of your video is therefore 24 Hz. Now comes the music.

«Pretend you can “photograph” the music and play these “photographs” in rapid sequence so that your ear hears the music as your eye sees the video. Using the mechanism of sampling, combined with a signal-processing process called quantization (if you’re interested, I’ll explain this later), you can actually “photograph” music. You just have to choose the resolution and sampling rate that will allow the computer to reproduce the music very faithfully (this means high fidelity, Hi-Fi). Another friend of yours who knows a lot about the ear and the brain tells you that for each of the two audio channels (we are talking about stereo music) 16 bit is a good resolution and 44.1 kHz is a good sampling rate (44,100 Hz, far more than the 24 Hz that suffice for video).

«In conclusion, the computer must save 16 bits for two channels 44,100 times per second, which makes about 172 kilobytes of information per second of music (you know that each byte equals 8 bits and each kilobyte equals 1,024 bytes). This mechanism is part of a standard called pulse-code modulation, or PCM, which is also used to save music on CDs. In fact, a CD, which can hold about 800 megabytes of information, can hold about 80 minutes of music. Remember that each megabyte equals 1,024 kilobytes, and do the math: 819,200 divided by 172 makes about 4,755 seconds, which equals about 79 minutes. Did I make myself clear?»

To this day I still pretend not to remember my son’s reaction… :)

The “whiskey” CD edition of my first album in my 1996 Sony Discman D-245.

The Compact Disc Digital Audio format was developed by Philips and Sony and described in a red-covered volume published in 1980. The first audio CD player was placed on the Japanese market by Sony in 1982. In 83-84 more than one million players and more than twenty-two and a half million discs were sold worldwide!

On the surface of the record, the bits in which the music is encoded are represented by microscopic indentations spirally etched into a layer of transparent polycarbonate. Unlike that of vinyl, the CD’s spiral starts from the center of the disc and ends toward the periphery. A reflective surface applied over the polycarbonate allows an optical sensor, placed in front of it, to detect the indentations when a laser beam hits them, and convert them into data. On the side of the reflective layer facing the laser lies a protective surface on which the artwork is printed.

Contrary to what one might think, there is no correspondence between an indentation and a one or a zero, which correspond instead to surface depth variation and lack of variation, respectively: entry into or exit from a pit corresponds to a one, while lack of variation corresponds to a zero.

The audio CD revolves at about 500 rpm when the laser is at the center and gradually slows down to about 200 rpm when the laser is at the periphery in order to maintain a constant linear and read rate. The bit rate of the CD, considering the specifications I tried to explain to my son (44.1 kHz times 16 bits times two channels), is thus constant: 1,411.2 kbps. In other types of compact discs, however, such as CD-ROMs, the angular rate is kept constant to maximize the read rate at the center of the disc.

By far the most popular discs measure 12 centimeters in diameter, those capable of containing about 80 minutes of music, but there are also so-called Mini-CDs that measure 8 centimeters in diameter and contain just over 20 minutes of music.

The official Philips story goes that the size was chosen, depending on capacity, so that one disc could hold Beethoven’s Ninth Symphony in its entirety.

I don’t remember how many CD players have been gathering dust on my shelves, but I still keep the ones I have been most fond of: my favorite is the Teac CD-P3500 that I bought in 1992; in second place comes the Technics SL-PG360A that my brother bought in 1994, the one I stole from him; and, last but not least, I cannot forget the 1996 Sony Discman D-245, my first portable player.

Worthy of honorable mention is the Super Audio CD (SACD), introduced in 1999 also by Philips and Sony, of which, however, I have never owned either a player or a disc, because in those years my attention, like that of most consumers for that matter, had already shifted to MP3 & Co. formats.

To conclude this third section, the CD player I have chosen for my most modern system is a Technics SL-C700, which combines high quality with refined design.

The MiniDisc

I discovered the MiniDisc while watching “Last Action Hero” at a movie theater in Los Angeles during the summer of 1993: in the middle of an unlikely chase scene behind the wheel, Detective Jack Slater, played by Arnold Schwarzenegger, replaces the disc in a portable Sony MiniDisc player.

The scene lasts less than three seconds…

[To be continued.]


Fabio Scagliola,