well, the da (digital audio) has no audio in ports. the two ports on the back are for headphones and apples own apple pro speakers that they made once upon a time. in fact those speakers are the only thing that i know of that works in that port. as for headphones, any standard 1/8" plug stereo headphones will work. put for a mic, you will have to get an audio input device, like griffn's imic, which is what i have on my da. then just about any 1/8" plug mic will work.