The vinyl record market it is constantly growing and for this reason more and more young people are approaching this world. But how are records produced on an industrial level? And why is their surface covered with tiny “V”-shaped grooves? We answer all the main questions about the world of vinyl starting from how they work.
How does a vinyl record work?
Imagine having one pin connected to one trumpetlike those of old gramophones. If we start singing inside the trumpet, the needle vibrates, because the sound of the voice is in fact nothing more than a vibration.
Now imagine rotating a vinyl record without grooves underneath the needle. One will remain imprinted on the vinyl trace which arises precisely from the vibration of the needle and which will be unique, because it is as if it were the written recording of the voice. This is the concept behind the vinyl record! In fact, if we take another needle and put it back into the grooves of the vinyl, it vibrates, and the vibration will in turn generate the starting sound.
The vinyl record under the microscope
If we observe a vinyl record under a microscope we notice that there are on its surface many small grooves. The turntable needle slides inside these, which is essentially a metal stick with a very small crystal at the end, usually a synthetic diamond.
If we observed it with an electron microscope, we would realize that these grooves are real V-shaped valleys, with each side inclined by approximately 45° compared to the other. The interesting thing is that these grooves are irregular, and it is normal for this to be the case, because these correspond respectively to the right audio channel (the external side) e left (the internal side).
So when we put the vinyl on the turntable and lower the needle, it slides into the irregular grooves and starts to vibrate. The vibration of the stylus is transmitted to the cartridge, which is a device that uses magnets or piezoelectric crystals to record the signal or send it to the amplifier, thus transforming the vibration of the needle into sound.
But from an industrial point of view, how is a vinyl record made?
The production of a vinyl record
The first step for making a vinyl record is the matrix: it is a aluminum disc on which a nib engraves a trace. In fact, the nib vibrates “in time” and actually affects the sound wave.
The second step instead is the one relating to the “molds”. Then we take the matrix and from this, through a series of steps that include the application of metals, you get gods “negative” records, which will act as a mold for engraving the grooves, which in fact they are, into the final vinyl a single spiral which goes from the outside towards the centre
Once you have the mold you can move on to the production of the actual vinyl. The actual discs are formed starting from small blocks of PVC plastic material that they can be black or colourful. These come heated with steam until it reaches a temperature of approximately 150 degrees. A “ball” of semi-molten vinyl is obtained which is then crushed to form the so-called “cookie”. The biscuit is placed under a hydraulic press with the mold mounted and, in doing so, the grooves are printed on vinyl which thus acquires the classic appearance ofdisk”. The labels are then applied, and the records are packaged and shipped all over the world!
Vinyl vs. CD: the differences in sound
Vinyl has sound “analog”. In essence, the vibrations of the needle allow the original sound wave to be recreated exactly. In the case of CDs, however, we are talking about digital sound, therefore the original sound wave is not totally reproduced but is sampled, therefore pieces of it are taken at regular intervals of time. The point, however, is that these samples are taken at such short time intervals – we are talking about 44,100 samples per second – that in reality our ear he can’t tell the difference.
Then in addition to this, however, there are also many other parameters to take into consideration, such as the dynamic range, the frequencies, the compression, how the master was made, the type of system used… in short, there are a thousand variables.
What we can say is that the CD it actually has a quality superior from one point of view exclusively technical… but that doesn’t mean it’s necessarily nicer to hear. Many, in fact, prefer vinyl precisely because of its imperfections and “warm” sound, due to the fact that being bigger we can enjoy it more and above all there is no button to skip songs, pushing us to listen the work in full, as the artist conceived it.
