One of the most important and unrecognised components of a CD Player is the DAC (Digital to Analogue Converter). The DAC in a CD Player is the component that is responsible for turning the digital audio (stored on the CD as a series of 1's and 0's) into sound that can be reproduced by speakers for us to hear. The differences in the sound quality of different CD Players is largely related to the quality of the DAC used.