Slater
Headphoneus Supremus
cool, i ordered 2 gold 4 pole 3.5mm jacks from ebay, should have it in a few days, im based in Aylesbury in Buckingham, thats around 50 mins from London and 30 mins from Oxford, ill have to look at some you tube videos, yes the wires are extremely thin, il have to stick with my 650s now and they will disturb my fellow passengers, ha, ive also bought a usb powered solder device, just have to figure out how to connect it to the four pole, your friend, doed he have a headphone repair business or something or is he a enthusiast with skills?
Also if you are based in America does anyone there sell legit cables? that i can order from online as its non existent on a google search
The UK person I am aware of builds and sells custom made headphone cables. So he is more than qualified to repair yours.
As far as who sells the full replacement cable (no soldering required), Sennheiser themselves are your only option.
Here’s the contact info for the UK office:
https://en-uk.sennheiser.com/service-support-contact-center