\rHi Sam:
The volume level is controlled by the Bluetooth enabled device (the source). In this case, you need to make sure you have the Bluetooth Transmitter enabled in the Yamaha and then you should be able to control the volume at the Yamaha Receiver (maybe with the remote control for the Yamaha). Try connecting the BTR1500 with your smartphone to certify they work. If they work with the smartphone than it is an issue with the Yamaha. And I believe the Yamaha has both a Transmitter and Receiver option depending on your application.
TL/4982\r