The era of CDs, and therefore all related technologies, is slowly but surely coming to an end. However, there are still lovers of classical performance of music or films. Just like gramophone records. To read CDs, special devices are used - CD players. The article provides an overview of such devices, their characteristics and interesting features.
History of Appearance
Strange as it may seem, scientists made advances in laser processing of CDs before they developed the first personal computers. Two Russian inventors, Alexander Prokhorov and Nikolai Basov, had a hand in this discovery. It was they who created the basis for the technology - the first cold laser. For which they received the Nobel Prize. Philips and Sony began to further develop and create full-fledged reading devices and, in fact, the media themselves.
The IT giants Microsoft and Apple were the main drivers in the popularization of CD technology.
For a long time, Sony and Philips could not come to a common denominator on the amount of data stored. Initially, Sony offered a 100 mm disc, and Philips -115.
According to one of the versions, the capacity of the disk should have been enough to record Beethoven's symphony No. 9 on it. This was the attitude that eventually became the CD standard.
In the end, both companies agreed that the standard would be 120mm, 74 minutes duration, and 44.1kHz.
Volume Development
Works on CDs did not stop and in 1996 a new standard appeared in Japan - DVD. Its minimum size is 4.7 GB. At that time, this was enough to record a full-fledged film in acceptable quality. The improvement of this technology has led to the possibility of using both sides of the disc, as well as several working layers on them. This increased the total capacity to 17 GB.
MP3 Arrival
Everyone who has ever downloaded music from the Internet has heard about the MP3 format. This format broke into the world of sound and turned everything upside down.
In general terms, MP3 is a codec, that is, a mechanism for compressing and decompressing audio data using a special algorithm. It made it possible to record music on compact discs with a total duration many times greater than the standard 74 minutes. In particular, about 200 songs in MP3 format could “enter” on a regular CD. It is currently the most popular and well-known music and composition file type.
However, to play this type, special players with the appropriate codec were required. This is how CD MP3 players appeared.
How does reading a CD work?
CD player manufacturesreading data using a laser beam. The principle is based on taking into account changes in the intensity of light reflection from the surface. Thus, the alternation of recesses on the basis of the disc is counted.
The rotation of the disc is due to the engine. The read head also does not stand still. With the help of servos, it moves from the center of the disk to its edge.
At the start of work, the device reads data from the header, which are located at the beginning of the disk, that is, where its diameter is smaller. With the help of the received information, the system learns in which place a particular section of a song, movie, or data is located. And can quickly position the reading head to the right place.
Sometimes the read head is dirty for one reason or another. And since it is inside the device, there is no way to arrange manual cleaning.
Therefore, the CD player's special cleaning discs are used. They can be either dry or wet. A special cleaning element is applied to their surface, which, when rotated, touches the lens, thereby cleaning it.
However, judging by user feedback, this approach does not always cope with its task, and many recommend taking the time to disassemble the device and clean the element manually.
First CD players
The founder of the series was the CDP-101 from Sony. At the time it was very expensive. The reading was performed by an optical sensor with a semiconductor laser through digital reading.
From the first conveniences, it is noted that it was possible to quickly select the desired composition and its position. The indicator was a simple display that showed the time of the piece of music.
The ejection tray was used as the disc feed. The entire control process was carried out using ten physical buttons.
This unit set the standard for the CD drive industry.
Estonia LP-001 Stereo
Estonia LP-001 became the first domestic CD player. It was produced by the Punane RET Tallinn plant.
It had all the functions inherent in this type of players - reading music tracks and quickly moving from composition to composition.
Of course, the expression "domestic" is a little misleading, since most of the components were from Philips, the leader in this industry at that time.
Modern turntable market
Today, CD playback devices can still be found on the shelves of electronics stores. True, now they are unrecognizable. A modern CD and DVD player is a multifunctional, complex technical device with many "chips" and possibilities.
Onkyo C-N7050
The appearance of the player is reminiscent of classic devices from the 90s. However, his "stuffing" says otherwise.
The machine is equipped with USB ports for connecting other devices. Thus, you can broadcast sound from more mobilegadgets directly to this CD player.
There is also an Ethernet port for connecting to a computer.
The list of supported formats is quite extensive - MP3, AAC, FLAC, WAV and other well-known types.
Philips EXP2540/02
A bright member of the family of portable CD players.
Made in a sleek white design. Supported formats are MP3, CD, CD-R, CD-RW, which it can play in various modes. For example, random or repeat one song.
Standard 3.5mm headphones are used as sound source. The LCD display is responsible for the indication during operation, which displays information about the album number, battery level, functions and track time.
Magic ESP function allows you to play songs without jerking during impact or shaking. It is based on caching parts of the track to avoid interruptions in the sound.
Panasonic SL-SW405
Another portable CD player. Its distinguishing feature is resistance to drops and shocks. The rubberized housing reliably protects against dust and even water.
LCD display shows current information about tracks, their duration, battery status.
It has a built-in equalizer that allows you to customize the sound for "gourmet" pure sound.
From interesting features - the ability to program a sequence of tracks.
Use two AA batteries as power sources. This compact CD player is ideal for listening to music on the go, while walking, jogging and traveling.
The future of CDs and user reviews
As such, CDs have no future. Technologies develop and new methods of data transmission and storage appear. Flash drives are already gradually conquering the market. Their volumes, speed and reliability are many times greater than the parameters of CD.
In this regard, users are increasingly evaluating CD players against the backdrop of new developments. For example, people often complain about the lack of wireless connectivity in stationary CD players. But after all, they were created precisely for this - to listen to music from a CD. There is no need to create other sound sources, especially such as a network. But some manufacturers are still implementing this feature into their products, thus making the classic CD player a common intermediary for audio transmission.
Another important requirement of users for CD-players, in particular portable ones, was the presence of the so-called "Antishock" system. That is, the mechanism of protection against shaking, which could suddenly interrupt the composition or even transfer it to the next one. There were also a number of responses to this at a time when CD players were a fad rather than an archaic device.
