Recorded music dates as far back as the 1880s even before the advent of advanced technology used in recording and playback devices – before the invention of tapes, compact discs, and MP3 players. These days, you would probably get most, if not all, of your music collection online.
You might find a few compact discs lying around, and you’re wondering how they work or think they are old school. Your old folks might not think so. Compact discs are still relatively new and classy technology to them depending on how they take their music serious.
A lot of vinyl enthusiasts claim that a better sound cannot be got from other means of playing music. After several years in decline, vinyl records have enjoyed spectacular renaissance over the last few years. Not bothered whether they relatively sound better or not, it is actually something interesting to know how they work if you are a music enthusiast just like me.
How Do Vinyl Records Begin?
Just to give a little bit of history- About a hundred and thirty years ago this year, a man by the name Thomas Edison demonstrated that vibrating air (sound) could be converted into a mechanical form and then back into sound. Sound recording was made more practical by Emile Berliner ten years later.
This was done by inventing the flat disc that evolved into the vinyl record today. In 1925, the invention of the vacuum tube brought in the era of electronic disc recording and playback. Disc-cutting heads could now be driven by electrical signals that are amplified could now. Also, groove modulations can be transformed into an electrical signal for amplification.
The mechanism behind How Vinyl Records Work
To understand the mechanism behind how vinyl records work you first need to understand how sound waves work. Sounds are basically vibrations, and these vibrations move through the air in waves. Sound energy is conveyed from the source through the waves to its surroundings.
Air particles results in the vibration of the eardrum and this makes sounds waves to be detected by human ears. The loudness of the sound depends on how big the vibrations are. The grooves you can find on a vinyl record are actually just like sound waves captured in a lacquer disc that we call a vinyl record. These 3-dimensional grooves are a recording of how the sound waves behave as they travel via the air.
Vinyl Record as an Analog Recording
You need to understand that a vinyl record is an analog recording as opposed to a compact disc which is a digital recording. Digital recording only recreates “snapshots” of the analog sound while the analog is able to catch the entire sound wave.
A record player is needed for a vinyl record to work and this is because it has a transducer that converts mechanical energy produced by the recorded vibration imprinted to the vinyl record into sound waves. These sound waves are amplified, and they have the ability to be broadcasted to the speakers. A typical record player has a transducer which is made up of stylus, amplifier, cartridge, and speaker.
What Is Stylus And How Does It Make Vinyl Records Work?
The stylus, recorder needle as many calls it is a sensitive needle that is made from hard metal and it is conical in shape. A vinyl record usually has a groove at the center which is fitted to the stylus. The vinyl record is fitted on the record player, and the stylus is gently placed on the vinyl record resting at the beginning of one of the grooves.
The sounds are imprinted on the groove and the stylus cuts or bump up and down through the grooves in the vinyl record. As the stylus scratches through the grooves, the sound manipulates the scratching into different sound waveforms or wavelengths.
The stylus is also usually a tiny crystal of diamond or sapphire mounted at the very end of a lightweight metal bar like a needle. It fits onto the end of an electromagnetic device called a cartridge that contains a piezoelectric crystal.
The microscopic bounces produced as the crystal vibrates through the grooves are transmitted down the bar. The metal bar presses against the crystal and every time it moves, it wobbles the crystal slightly, producing an electrical signal.
As the vinyl record steadily rotates and the stylus begins to move, it pushes the magnet up and down past the coil and then produces the electrical signals in that way. These electrical signals are then fed to the amplifier to create sound through the speakers.
Ideally, the playback stylus follows the groove modulation as it was inscribed by the cutting head. In practical sense of it, a number of factors introduce differences between the motions of the cutting stylus and playback stylus as it pushes through the inscribed grooves.
Factors Showing Differences Between the Cutting and Playback Stylus Motions
First, because the shape of the cutting and playback stylus is different, tracing distortions are produced. The cutting stylus has sharp edges, and playback stylus is polished smooth, making it impossible for the two styli to follow exactly the same path.
The second is mistracking, and this happens when the stylus progressively breaks contact with the groove walls. This is caused when the stylus encounters a complex and high-level modulation groove. Mistracking does not only add distortion; it also damages the vinyl record as the stylus is slammed back and forth between the groove walls.
Another one is the tangent error. It is the geometric relationship difference between the stylus and the groove. A cutting head moving in a straight line across the disc inscribe master lacquers and the disc is played back by pivoted tonearms in an arc. When an offset is added to the tonearm, the tangent error is reduced effectively due to the bend at the cartridge end.
But this tonearm offset introduces a force that pulls the tonearm towards the spindle—the familiar skating force that we compensate for with the tonearm’s anti-skate adjustment. Skating force is as a result of the friction between the groove wall and the stylus, pushing the stylus toward the record center and pulling it away from the tonearm pivot point.
The skating force is counteracted by applying an equal but opposite force to the tonearm. Take note, tangential-tracking tonearms take the same path the cutting head follows. This allows the playback stylus and the cutting stylus to maintain the same geometric relationship with the groove.
Further Information on How Stylus Makes Vinyl Records Work
Consequently, no skating force is developed with tangential-tracking tonearms. However, in practice, the arms of tangential-tracking are noticeably fussy. Specifically, it is not possible to apply equal force to the groove walls. The friction pushes the cartridge the outer groove wall so as to make following the spiral track possible.
A stylus sails through the vinyl record outer grooves with ease; the linear speed as seen by the stylus is quite high—20″ per second. This means that high frequencies are inscribed with long wavelengths. This makes it relatively easy for the stylus to correctly track complex passages cut at a high modulation level. But the linear speed gradually decreases as the stylus moves toward the inner grooves.
So, what next?
The record spins at a constant angular velocity (360° in 1/33.3 minutes). But the distance the stylus travels in each revolution is much shorter on the inner grooves than the outer grooves. This means that a 10 kHz signal is inscribed with a wavelength of 0.002″ at the outermost groove, but with a wavelength of just 0.0008″ at the innermost groove.
The same information is filled into a smaller space. Because of these inherent characteristics of the vinyl record, inner grooves are more difficult to track and are prone to higher distortion. The stylus can respond to, and recover the information encoded into a vinyl record with a signal-to-noise ratio of 50dB; a physical feature in the groove of less than 0.1 microns.
To put this task into view!
Human hair has a diameter of about 75 microns. That the vinyl record works is amazing; that it works so well is nothing short of miraculous. One would instinctively think that the Compact Disc with its laser-based optical system is vastly more precise, refined, and resolving than the crude technology of dragging a piece of diamond through a modulating groove in a plastic disc. For example, about 50Cd tracks would fit inside the middle portion of a typical vinyl record groove. But consider this, that piece of a polished diamond can resolve physical features in the groove of 0.1 microns. But the smallest pit or land length on a Compact disc is 0.8 microns.
A lot of DJ and record collectors claim and show a strong belief that the vinyl sound is much warmer and superior than digital music and that is why vinyl records has always been the first and top choice for any person with an expert knowledge in music.
The renewed attention to vinyl is evidence to its superiority over all music formats. The vinyl record continues to remain the most impressive format for recording singularly and reproducing music. It is actually difficult to imagine how or when a vinyl record could ever be replaced by a new music format claiming to do it better.