CD changer

A CD Changer holds multiple Compact Discs and allows the user to access (or play) any of them, one at a time. CD changers are commonly found in home cinema systems, cars, and less often in computer equipment.

Prior art

Prior to real CD changers being introduced an attempt was made to copy the double cassette players found in many audio systems; CD players with two separate, fully functional CD players was made. Double cassette decks were never replaced with cassette changer, mainly because a double cassette deck could copy from one cassette to another. Double CD decks on the other hand did not have this copy functionality, since recordable CDs were not commercially available, and thus the shift to changers was swift, removing the need for duplicate parts.

Main types of CD changers

External cartridge

External cartridge CD changers have one or more cartridges that the user loads with typically 5 to 10 CDs and then inserts into the CD changer. The CD changer can then remove one CD at a time for playing. This type of player is convenient because the user typically owns at least two cartridges and therefore can load a second one to quickly switch with the first one.

Internal cartridge

Internal cartridge CD changers work on the same basic principle as external cartridge players, except that the cartridge never leaves the CD player. This type of CD player accepts multiple CDs through a single slot and stores them internally.

Carousel

A carousel type CD changer consists of a circular platter that holds three to seven CDs. The carousel ejects from the CD changer for the user to load CDs on to it. Once back inside, the CD changer can rotate the carousel to access all the CDs. Most carousel CD changers will allow the user to rotate the carousel while open and change (say) all three CDs if no CDs are currently playing, or to eject the carousel while one CD is playing to change (say) the two additional CDs.

Evolution

Digital audio players have surpassed the concept of CD changers; for example, the first generation iPod can hold an equivalent of 5 discs with a 128k sample rate for each song; thereby the iPod is 1/10 the size of a CD changer cartridge, and about 1/20 the size of a carousel changer. Solid state flash-based digital audio players have rendered compact discs and thus CD changers obsolete for some purposes. However, most forms of digital music use a lossy compression scheme and therefore are unacceptable for professional applications and other demanding users.