How Record Players Work

Audio Tech Image Gallery Record players started the trend of portable music by making it accessible to people. See more audio tech pictures.

©iStockphoto.com/Arkady Chubykin

If you're in the mood for some good music, you might flip through the neatly shelved rows of album covers, make your selection, and slide the shiny, round disc out of its sleeve. Holding it by the edges, you carefully slip it into place, anticipating the rich sounds you will soon hear. But it's not the sound of a CD playing your favorite music -- it's a record.

As the disc begins to spin on a turntable, an arm drops to the outer edge of black vinyl record. After a brief pause, you are greeted by tunes that sound rich, but not perfect, and sometimes the needle skips across a groove, interrupting a song.

Before the 1970s -- before the invention of tapes, compact discs and MP3 players -- people listened to recorded music on record players. There was no fast forward, rewind or shuffle. Instead, you chose an album and enjoyed about 25 minutes of music by one artist before flipping it over for more or putting another record on the turntable.

From the time the phonograph was invented in 1877 until it was slowly phased out and replaced by other music media nearly 100 years later, the technology used to play recorded sounds changed only slightly. And today, records and record players are even enjoying a comeback.

In this article, we'll look back to see how Thomas Edison's favorite invention works and how it has influenced on culture and society. Up first, we'll see how the idea of recording sound came to be, and whether Edison was actually the first person to discover it.

  1. Edison's Discovery
  2. Evolution of the Record Player
  3. How a Vinyl Record is Made
  4. How Records Are Played
  5. How Records Influenced Culture
  6. Record Resurgence

In 1877, Thomas Edison and his assistants attached a needle to the diaphragm of a telephone receiver with the idea that the needle could be used to etch an impression of sound onto quickly moving paper, thus creating a recording or sound writing.

Edison understood that sound is the vibration of particles across a medium, such as air, in waves. He developed a way to imprint or record the waves so that they could be played back or turned back into sound using a second needle.

He eventually designed a device he called the phonograph that had a brass cylinder wrapped in tinfoil, which rotated and moved lengthwise when turned by a hand crank. On one side was a diaphragm, or very thin membrane, connected to a needle. When sound waves were forced into the receiving end, it caused the membrane to vibrate and the needle to etch a groove into the foil as the cylinder was being turned by the crank, thus recording sound. A second needle and an amplifier were on the other side. When the cylinder was set to the beginning and the needle placed in the grooves, the original sound was reproduced as the vibrations were amplified.

Edison created his first voice recording by shouting the words to "Mary had a little lamb" into a mouthpiece, causing the sound waves to vibrate a needle and etch the nursery rhyme into tinfoil for playback.

The phonograph was a breakthrough, as it had the ability not only to record sound, but to play it back. Edison originally thought that the phonograph would be useful in offices for dictation, for families to record their history or for teachers to record lessons. He considered applying the technology to toys such as talking dolls and music boxes.

But the phonograph proved too difficult for most people to use, and the tinfoil on which the recordings were made did not last. Interest in the machine waned as its applications proved impractical in its current state. Edison put it aside to pursue work on other inventions. When he resumed work on the phonograph nearly 10 years later, another inventor had moved it one step closer to the record player.

Who Was First?

Even before Edison's invention, other inventors made discoveries about recording sound. In the 1850s, French printer Leon Scott used a phonautograph to imprint sound waves onto a glass cylinder. And in 1877, just before Edison's discovery, another French inventor, Charles Cros wrote of a machine called the paleophone that could record sounds, but he never patented it [source: Schoenherr].

Evolution of the Record Player

An old gramophone with a horn and flat disc like this is similar to Emile Berliner's design.

©iStockphoto.com/Faruk Tasdemir

Although Edison temporarily stopped work on his phonograph, interest in recording and playing sound was not abandoned. Ten years after its invention, in 1887, a German inventor in the U.S. named Emile Berliner built on the ideas of Edison's design. Instead of a cylinder with the sound etched in tinfoil or wax, he developed a device that rotated a hard rubber (and later, shellac) disc on a flat plate by the turn of a crank.

But unlike its predecessor, the phonograph, Berliner's machine, the gramophone, could only play recordings. So Berliner started the Gramophone Company, which manufactured not only the machines, but the records played on them. What was lost in the ability to both record and play back sound in one machine resulted in a new system whereby mass-produced recordings could be played and shared repeatedly.

Berliner's company merged with that of inventor Eldridge Johnson to become the Victor Talking Machine Company in 1901. It manufactured and advertised both gramophones and records. Johnson refined the design of the gramophone, which until that time had been dominated by a large horn to amplify the sound. In order to fit more comfortably in a home, the horn was tilted down and the entire device placed in a cabinet. This new design, introduced in 1906, was called the Victrola. Meanwhile, the company also manufactured discs recorded by famous opera singers and musicians, giving the public unprecedented access to music [source: Shoenherr, Morton: Phonograph].

Over time, the design of the gramophone and the recording process were continuously changing, yet the core elements of the needle in a groove remained the same. By the mid-20th century, most households had what was then commonly known as a record player and most recently called a turntable. Its mass popularity lasted until about the mid-1980s when cassette tape recordings overtook records.

We're on our way to finding out what exactly goes on during a record player's playback, but first, we need to understand the basics of how a vinyl record is created.

How a Vinyl Record is Made

The success of the gramophone to play recorded sounds was dependent on the ability to mass produce records.

The process of making records has its roots in Thomas Alva Edison's phonograph. First, a master recording is made, usually in a studio where engineers perfect the recorded sound. Then an object called a lacquer is placed on a record-cutting machine, and as it rotates, electric signals from the master recording travel to a cutting head, which holds a stylus, or needle. The needle etches a groove in the lacquer that spirals to the center of the circular disc. The imprinted lacquer is then sent to a production company.

There, the lacquer is coated in a metal, such as silver or nickel, to produce a metal master. When the metal master is separated from the lacquer, the resulting disc has ridges instead of grooves. The metal master is then used to create a metal record, also called the mother, which is then used to form the stamper. Stampers are just negative versions of the original recording that will be used to make the actual vinyl records.

Next, the stamper is placed in a hydraulic press, and vinyl is sandwiched in between. Steam from the press softens the plastic as the stampers push an impression of the master recording onto it. Finally, the disc is stiffened using cool water.

Once the record is ready to be played, it will need a proper machine to bring its sounds to life. Up next, we'll break down how exactly a record player's components work together to bring you the music.

What's in a Number?

Records are often referred to by the number of revolutions that they make on a turntable per minute, or RPMs. This number gives the listener an idea of how much is recorded on the record [source: Phonograph].

How Records Are Played

The vibrations from the record's grooves travel up by the needle, through the cartridge and the arm to the amplifier, where they are magnified into sound waves.

©iStockphoto.com/Iñaki Antoñana Plaza

For almost a century, the record player was the most common way to listen to recorded music, speeches, languages and lessons. The design has been refined over the years, but the concept changed little, and the basic parts have remained the same.

The turntable is the circular plate on which the record sits. A rod positioned in the center holds the record (which has a hole in its center) in place. The metal turntable is covered in rubber or plastic, which protects the record from being scratched. The turntable rotates or spins with the help of either a belt drive or direct drive system.

The stylus, or needle, is the smallest and perhaps the most important component of the record player. It is made from a diamond or other hard material, shaped like a cone and suspended by a flexible strip of metal. The pointed end is the only piece that touches the top of the record and it rides around the spiraling grooves of the disk, picking up the vibrations which are ultimately turned back into sound.

The stylus sits at one end of the tone arm, which is mounted to the side of the turntable and sits parallel to the record. With the needle or stylus placed in the outermost groove of the record, the tone arm follows the groove as it spirals inward, traveling across the record in an arc as the record spins beneath it. As this happens, the vibrations travel along a flexible metal strip and wires housed in the tone arm to the cartridge in the end of the tone arm. The cartridge receives the vibrations, which are converted to electrical signals through a coil in a magnetic field. The electric signals are carried along wires to the amplifier which enhances the power of the signal. Finally, the signals are converted back to sounds that come out through the speakers.

Initially, recorded sounds were mainly monophonic, meaning all of the sound signals are combined and come through one speaker or channel. The introduction of stereophonic sound systems in 1958 allowed for a richer, more lifelike sound as two sets of sound waves were recorded. When played, the vibrations travel simultaneously along two different channels and are converted and dispersed through two different speakers.

Record players became more common as recorded music grew in popularity, but not everyone jumped on the bandwagon. Read on to discover which famous band leader didn't like the idea of recorded music.