E Strings when i strum it open!?

E String buzzes when i strum it open!?

I have a Mitchel MU70. I changed the strings to Martins about a month ago. I noticed a buzz when I play an open E string but when i play on the first fret or second etc theres no buzz. I think I can hear the buzz from the nut or tuning pegs, not sure. Please help with this problem. Thank you!

EDIT:

I noticed the higher I tune it the higher the buzz. If i put it at D theres no buzz. But once I tune it to E...BUZZ D:

I would make sure that the tuner is screwed down tight enough so there is no vibration. try and tap the tuner peg with your finger and see if you get a vibration.