A player or stereo, is the component of an audio system capable of reproducing musical media or the signal of a radio station.

Today, a stereo player rarely uses old media such as vinyl or magnetic discs. Let's then give a list of the media or sources currently most used by a player:

  • CD/DVD
  • USB devices, such as pen-drive (stick), hard disk etc
  • MP3 players or portable audio players, such as the iPod
  • FM/AM radio

In order to use some external media, such as hard drives, pendrives or MP3 players, it is preferable that the player has input ports such as:

  • USB
  • AUX
  • 30-pin Apple Dock input (for iPod, iPhone, iPad etc)

Digital media readers normally have the ability to read various formats, these being the most common:

  • MP3 (MPEG) - The most popular
  • WMA (Microsoft) - Widespread on Windows operating systems
  • Vorbis (Open Source) - The most efficient in terms of compression/quality
  • AAC (MPEG) - Used primarily by Apple

An audio player often has a built-in amplifier, the more powerful it will be, the greater the possibility of listening to music at high volume. In this case, it will be useful for the player to have treble and bass controls.
Fader control is also useful, especially on a car or boat, for balancing the sound towards the front or rear speakers.

If you want to install a subwoofer, you will need to purchase a separate amplifier and that the stereo has a preamp output. In fact, the subwoofer needs specific controls that only a separate amplifier can guarantee.