The CPA-100 is an easy to use compact 4-channel half-rack preamplifier and media player. It features a built in MP3 player via the front panel USB input. You can playback audio from any smart phone or portable MP3 player by connecting the device front panel mounted Ø3.5 input. Two rear mounted stereo RCA inputs allow the connection of various audio devices such as, CP player, DVD or Blu-ray players, satellite or cable set-top boxes.