The language of the FiiO Music app defaults to follow the system's. You
can also go to FiiO Music app-> Settings->Languages to choose the
language independently.
6. How to enable the USB DAC function?
For Mac computers, the JM21 runs driver-free.
For Windows computers, please make the settings as the followed
steps.
1) Install the FiiO DAC driver in the computer first.
2) Switch the working mode of the JM21 to USB DAC mode on the
drop-down menu or go to Settings->Mode choose menu to enter the
USB DAC mode.
3) Connect the JM21 to the computer by the USB port. Select the JM21
as the audio input both in the computer and the music app, so it can
work.
Notes:
When in the USB DAC mode, the JM21 does not support Bluetooth
transmitting.