Is your included cable stable even if you wiggle it up and down? Does it disconnect at all?
Yes, I actually tested this to make sure I was making a solid connection. So after a couple of hours troubleshooting with different headphones, different input devices, different audio apps. It seem the iPhone 6 plus is the issue here. My iPad and iPod touch I use for testing is clear.
I tested the iPhone further with my O2+ODAC and m9xx and these render no static or crackling. So there seems to be an issue with the communication between the iPhone and the Mojo. I looking further into the .ipsw of the iOS to see if that makes a difference as well
I am also going to test two other iPhone 5's to make sure its not just an iPhone issue as well.