FiiO BTR13 Bluetooth Headphone Amplifier with LDAC, aptX Adaptive, aptX HD, AAC (Dual CS43131 3.5mm Unbalanced & 4.4mm Balanced Output) (Black). The BTR13 uses the Qualcomm QCC5125 Bluetooth chip, supporting Bluetooth formats such as LDAC, aptX, aptX LL, aptX Adaptive, aptX HD, AAC, and SBC.