I have five iems (Ito3, Lab2, Vega, Andromeda, F7200) with MMCX and none of them have ever given me a single problem. However, the two pins on my JH13Pros including the socket have been broken three times, I have to return to Jerry Harvey for repair three times costing me three hundred dollars or more. The socket for the two pin connector will first become loose and then the cable will fall off, very bad design. That is why JH audio eventually develop the locking four pin connector. Drew is not accurate on this.