Convert 3-pin to 4-pin XLR?

Headphone amps that have balanced outputs for fully balanced headphone typically use 4-pin XLR connectors for the headphone cable itself.  This is a headphone output socket.

Mine was the same way. I put on my neighbors glasses by accident. I thought I was having a stroke.. Double vision.. Took me a few seconds to figure it out. LOL
My neighbor was laughing his A$$ off, he did it on purpose.

Same guy put a 200lb rock in his little brothers front drivers seat. His little brother weighed about 130lbs. No way to get it out. 3 buddies of his to get it out before he could go to school. 30 degrees outside.. Never said a word, we just watched.

That was 50 years ago too.  Corvair I think.. or English Ford..

Regards

Thanks, I got a chuckle. Have a Happy Thanksgiving!

Never mind , my bad. XLR inputs on the amp are 3-pin. Duh. Sorry.