Blue yeti audio output echoes and cuts in and out

Using Blue Yeti Mic on MacBook Pro. If I set audio input and output to the yeti and plug headphones into the yeti, I get severe echoes and cutting in and out on any audio played. It is not coming from the input, it's just the sound processor or something. So if I try to skype the other person'a audio is all messed up, but input is fine from my end. If I play a song in iTunes, same problem.