https://github.com/ploopyco/headphones/issues/28

The Ploopy open source headphones project (you can print them off for free with a 3d printer) is looking for someone who knows how to design a headphones I/O that includes a 2.5mm jack

I may have explained this horribly, I do not understand this stuff

No, I am not affiliated; even if I was it’s literally open source lol.