Fiio BTR15 review: This Bluetooth DAC is the ultimate valueThe BTR15 has everything you need in a budget DAC. Thanks to Bluetooth 5.1 connectivity, 4.4mm port, and increased power, it can drive demanding headsets, and you get a clean sound.
Source: Fiio BTR15 review: This Bluetooth DAC is the ultimate value (https://www.androidcentral.com/accessories/audio/fiio-btr15-review)