Ipad to replace cd player?

Reluctantly I have been forced to connect either my ipad or ipod to my system for audio. I was always against it so far! but wife and kids feel more comfortable with them as opposed to CD player. My system is Infinity intermezzos hooked to Lexicon MC12, CX-5, and a lexicon RT20.
How much of a deterioration in audio quality do you get playing mp3 off ipad etc?
Any suggestion reg good cable for hookup?