The FiiO BTR13 Bluetooth Headphone Amplifier is a portable DAC/amp designed for high-quality audio at home or on the move. It features dual CS43131 DACs, with each channel handled separately in a fully balanced design to reduce interference and enhance detail. The amplifier offers up to 220mW of balanced output power, capable of driving a wide range of headphones. Seamless one-click switching between PC, Bluetooth, and Phone modes is available via a three-position toggle switch, allowing it to function as a computer sound card, Bluetooth decoder, or audio dongle. It supports high-resolution audio transmission up to 96k in both Bluetooth and USB DAC modes, utilizing the Qualcomm QCC5125 Bluetooth chip and supporting codecs like LDAC. A global 10-band Parametric EQ (PEQ), adjustable through an app or web interface, allows for personalized sound tuning. The device includes both a 3.5mm single-ended headphone jack and a 4.4mm balanced headphone jack for broad compatibility. An independent headphone amplifier power supply with low noise and high current output boosts performance. Operation is made easy with a 0.96-inch colour IPS display showing settings and functions. The 3.5mm jack supports CTIA standard in-line controls for microphone and playback adjustments.