Cracking noise in Logic Pro X
I've had my MacBook Pro (Retina, 13", End of 2013) for quite over a year now and I've been using Garage Band for a long time and now I switched to Logic. My problem is, that whenever I record something on Logic Pro X (and also Ableton Live 9), that after some time of recording and arranging a cracking noise appears whenever I play back the track. As soon as I export the track onto iTunes that cracking sound is gone. I tried to figure out where it came from, but nothing makes sense. At first I thought it might be my M-Audio Fast Track Pro and that it was coming from my audio lines, but the noise also appears when I'm only working with MIDI.
Please help me figuring out where it comes from, cause I would really want to perform live with Ableton, but that won't be possible with this sound problem!
MacBook Pro with Retina display, OS X Yosemite (10.10.1)