You can run it from an external power supply to run high-powered headphones without worrying about draining the battery. There are three modes: PC powered, Bluetooth DAC/amp, and phone dongle.

Not wanting to spend the money on a dedicated power supply, he looked around for a cheaper solution and found one in an off-the-shelf ATX computer power ... could supply 25 amps on the 12 volt ...

When in desktop mode, if you connect the BTR 17 to a phone as a dongle DAC and headphone amplifier you can also choose to connect an external power supply which enables the device to drive power ...