The FiiO BTR15 sits at the top of FiiO's BTR line of portable Bluetooth DAC and headphone amplifiers, succeeding the BTR7 with a more compact form factor and a dual-core processing architecture that handles high-resolution audio across three distinct operating modes. Where single-chip designs must compromise between Bluetooth decoding and USB audio performance, the BTR15 pairs a Qualcomm QCC5125 Bluetooth SoC with an XMOS XU316 16-core co-processor, allowing each chip to excel within its own domain without sharing resources.
Three Modes, One Button
A dedicated PC/BT/PHONE mode button on the side of the BTR15 switches between Bluetooth receiver mode, USB DAC mode, and phone (wired analogue input) mode. In Bluetooth mode, the QCC5125 handles decoding of LDAC, aptX HD, aptX Adaptive, and SBC streams at up to 96kHz/24-bit. In USB DAC mode, the XMOS XU316 takes over, supporting asynchronous PCM up to 384kHz/32-bit and native DSD up to DSD256 with no driver required on Windows or macOS. The BTR15 also supports MQA Full Decoding in any app, enabling master-quality audio files to unfold correctly without needing a dedicated MQA-licensed streaming service.
Dual ES9219MQ DACs and Independent Amplifier Power Supply
The BTR15 uses a pair of ESS ES9219MQ DAC chips configured for fully balanced operation. FiiO engineers have given the headphone amplifier stage its own independent power supply, isolating it from the DAC circuitry and reducing interference. This arrangement increases the balanced output power by approximately 40% compared to a shared power design, resulting in 340mW per channel into 32 ohms via the 4.4mm balanced output. The 3.5mm single-ended output runs in a parallel output configuration, also benefiting from the improved power delivery to deliver 125mW per channel into 32 ohms. Output impedance is below 1 ohm single-ended and below 1.5 ohms balanced, preserving frequency response accuracy with sensitive in-ear monitors.
Global Parametric EQ
The BTR15 implements a global parametric equaliser that operates in all three modes. In Bluetooth mode, EQ processing runs through the QCC5125's built-in DSP for Bluetooth streams up to 96kHz. In USB and phone modes, EQ processing runs through the XMOS XU316 for PCM content up to 192kHz. Users can adjust specific frequencies, gain levels, and bandwidth values directly through FiiO's companion app, enabling precise tonal adjustment to suit any headphone or personal preference.
Build and Display
The BTR15 measures 32 x 72.2 x 12.5mm and uses an aluminium alloy middle frame flanked by curved hot-bent glass panels on both the front and rear. The curved glass improves grip and gives the device a more three-dimensional appearance than flat-backed designs. A 0.96-inch OLED display with 96 x 96 pixel resolution shows playback format, sample rate, volume level, battery status, and other device information at a glance. Two colour options are available: Black and Blue.
Battery and Charging
The 550mAh lithium-ion battery provides approximately 8 hours of continuous playback and charges fully in under 2 hours via USB-C. FiiO has implemented both hardware and software battery protection to manage charge cycles and preserve long-term battery health.
