Originally Posted by
mckvakk
i couldn’t find a good thread for this, so I hope a quick question is ok.
There's a thread on everything to do with the IFE below. 777-300's have the Thales system which supposedly has a regular 3.5mm jack.
Your Guide to BA's In-Flight Entertainment
But in my experience, go and buy an adaptor and keep it in your bag for travelling - they're only £3 for 2 and available with Prime delivery.
https://www.amazon.co.uk/Mobi-Lock-Converters-Headphones-Earphones-Airplane-Earphone-Adapter-Pack-
2/dp/B00NLL1HHU/ref=sr_1_1_sspa?ie=UTF8&qid=1537432349&sr=8-1-spons&keywords=3.5mm+airplane+adapter&psc=1
Edit: Sorry I'm thick and didn't read all of your post to see that you had one previously
But I'll leave my comment for other people that pass by and might want to buy one!