Share your experience!
Is there or is there going to be any support for previously released accessories for this phone?
The MDR-NC750 earphones in particular as i feel they are still relevant in todays market as well as the STM10 microphone.
Sony made a big deal about the return of the 3.5mm jack so I would have thought it would support most accessories straight out of the box...... unless i'm missing something??
Test
Try some other headphones.
If others do connect then compare the plugs.
If none function it may be a hardware problem.
Some Headphones/Microfones need an adapter to change the "pins". Many lavalier microphones has this adapter included, perhaps your MDR uses this differen pin occupancy.