I recently bought this product. The jack is of 1.5 mm in this. I have tried to use all kinds of wires inside this jack but none of them fit properly. The standard male to male wires are also too loose for it. Right now currently I have made some temporary solution to it by looping a single stand wire and then putting it inside the jack but it would be better for my project to use something that is standard are more reliable like a male to male wire. So any suggestions on what kind of male connector I can use for this??