I've been looking at the A&K120 mkii and specifically trying to fathom out the balanced output.
This is a 4 pole balanced 2.5mm TRRS socket, right next to the standard 3.5mm socket.
All I can fathom out is that by adding an extra ring on a 2.5mm plug, separate fully balanced left-right signals can be passed into compatable gear.
Has anyone had experience of fully balanced in-ear headphones? The only ones I've seen are JH Audio Roxanne at £ totally laughable and some modified Sennheiser IE800 that are still £ laughable.
The cynic in me says that it's just marketing waffle to brainwash consumers that they won't get the best sound unless they listen down the 2.5mm jack.