Pure Music mode
Third party applications will be automatically disabled while FiiO Music app will
be auto-enabled. It can be switched to other modes on the drop-down or
settings menu.
AirPlay
The M21 can be connected to Apple devices, receiving audio signals transmitted
from them.
USB DAC mode
In USB DAC mode, the M21 can be connected to other devices like a computer,
working as a USB DAC/Amp. It can be switched to other modes on the
drop-down or settings menu.
Notes: when the M21 is going to work in the USB DAC mode for the first time,
FiiO's exclusive USB DAC driver is required. Please download it on our website
and follow relevant instructions to install it.
Bluetooth Receiving mode
The M21 can be connected to Bluetooth transmitting devices like a mobile
phone, working as a Bluetooth DAC/Amp. It can be switched to other modes on
the drop-down or settings menu.