Has anyone ever seen round thing where the cables join on the PS500? I've never seen anything like it, and was puzzled. It terminates in what sure looks like an original Grado plug (with the word "GRADO" on it etc.) and the cable feels like the familiar original Grado cable. \
I have owned a handful of grados and have seen many grados online or in person, so I can say that I have never previously seen a circular disc cable splitter on a Grado. Did a previous owner mod your PS500?