Sony NW-A55 Help Manual page 97

Note
The battery life becomes considerably shorter when the Bluetooth function is active.
There are some restrictions on sound output through a Bluetooth connection.
Even if you connect a pair of headphones to a headphone jack, sound will not be output from the headphones. Sound is output
from the Bluetooth device preferentially.
You cannot listen to FM radio while there is an active Bluetooth connection.
You cannot listen to played-back sound wirelessly while the USB-DAC function is active.
If sound is interrupted or skips during a Bluetooth connection, try the following.
Place the player and the Bluetooth device closer together.
Select [SBC - Connection Preferred] by tapping the following menu items.
– [Settings] – [Audio Device Connection Settings] ([Bluetooth]) – [Wireless Playback Quality].
A Bluetooth connection is terminated automatically in the following cases:
The battery of the player has run out.
The player is turned off.
When there is an active Bluetooth connection, the sound quality settings are invalid.
The contents of the Help Guide may be subject to change without notice due to updates to the product's specifications.
Related Topic
Connecting the player to an unpaired Bluetooth device for the first time
One-touch connections with a Bluetooth device (NFC)
Configuring the Bluetooth function (Bluetooth transmitting mode)
Notes on the Bluetooth function
4-740-523-12(1) Copyright 2018 Sony Corporation
97