I have a pair of quite expensive (well by my reckoning) Bose noise Cancelling Headphones.
The 3.5mm 3 pole stereo plug needs replacing - intermittent contact of one core.
Bought a quality gold plated right angle plug, which comes with neat stress relief bushes.
The issue is the flexible cord itself .... it is a thin very flexible item ... the cores once exposed are not individually sheathed in pvc ... but what seems like a woven sheath thst just frays if you try to strip with a knife.
The overall diam of cable is 1.9mm The diam of each insulated core is 0.39mm
If that helps give an idea of cable type ...I have taken a pic:
Don loads of cable soldering in the past ... but prepping the ends on this cable is proving difficult