This is the replacement part for you to put the MMCX connector on your KOSS KSC75.
You still need to get female connectors to fit this design. And you need some M2x3mm screws to assemble the part onto the driver. Or you may just glue them on.
*The holes on the headphone back are precisely 2mm. So if you use 2mm scerws they will be too loose. The slightly staggered holes make the screw tighter. Or you may just use some method like instant glue or thin pieces of plastic to tighten the holes on the headphone back. Then you can use a "normal pitch" file which has just aligned holes to the headphone back
