How do vinyl records work?

Surrounded by so much technology today, it is common to focus our curiosity on the newest advances and to question the unknown, but it is just as interesting to go back a bit and appreciate the technologies we usually take for granted and simply let go unnoticed. That is why I will talk about an object that everyone knows but few know how it works: vinyl records.

In simple terms, a vinyl record produces sound by converting mechanical movement into electrical signals.

The process begins even before the needle is dropped on the record, because records are made with great care and their proper operation depends on microscopic grooves that at first glance appear identical, but have tiny irregularities in depth and width that cause the sound to be interpreted in the desired way; they are like a representation on a very small scale of the sound waves of the songs. A slight error in the patterns of a record would drastically distort the melody, with a difference of only a few micrometers.

The needle follows the path of the grooves and picks up their irregularities. This movement makes two magnets and two coils, located on either side of the needle, generate electrical signals; this assembly is called a phono cartridge.

Then the signals generated in the cartridge, already split into two stereo channels (one per groove wall), go to a preamplifier and an amplifier so that the sound can play through headphones or speakers.

There are also several aspects to consider to achieve an ideal reproduction of the record, such as the shape of the needle, the material it is made of and the angle at which it is positioned. Without a doubt, when it comes to convenience and practicality, vinyl records do not rank first, but more than 100 years after its creation it is still an astonishing invention.