CD player

A CD player is an electronic device that plays audio compact discs. CD players are often a part of home stereo systems, car audio systems, and personal computers. They are also manufactured as portable devices. Modern units can play other formats in addition to PCM audio coding used in CDs, such as MP3, AAC and WMA. DJs often use players with an adjustable playback speed to alter the pitch and tempo of the music. CD playback functionality is also available on CD-ROM/DVD-ROM drive equipped computers as well as on DVD players and CD-ROM/DVD-ROM based game consoles.

Inner workings

The process of playing an Audio CD, touted as a digital audio storage medium, starts with the plastic polycarbonate disc, an analogue medium that contains the digitally encoded data.
The data is read out by loading the disc in the player's mechanism that scans the spiral data track using a laser beam. The tracking control is done by analogue servoamplifiers and then the high frequency analogue signal read from the disc is digitized, processed and decoded into analogue audio and digital control data which is used by the player to position the playback mechanism on the correct track, do the skip and seek functions and display track, time, index and, on newer players, title and artist information on a display placed in the front panel.