To clarify the firmware update, there are three parts. You need internet access, correct type of computer OS, and two different cables.
Network firmware update - run Esoteric Sound Stream app on iPad or Android, and it will prompt you to update it (via internet) to 12.3k if necessary
I/F firmware update - this needs to be connected to the micro USB port (normally unused)
USB MQA firmware update - this needs to be done over the USB-Type B port for USB DAC input
The I/F and USB firmware can be downloaded from:
https://www.esoteric.jp/en/product/n-01xd/download
Important notes:
- Make sure you connect using the correct cable to the correct port (this is super important)
- Make sure you have downloaded the correct software for the correct model - do not attempt to use a firmware not meant for your model (someone did that and bricked it)
- Make sure you use the real correct type of required computer OS, not virtual
- Follow instructions carefully
Doing these wrong could be disastrous.
If you need help, please check with your dealer or Esoteric.