FiiO BTR15 Bluetooth Headphone Amplifier

The FiiO BTR15 is a pocket Bluetooth DAC and headphone amplifier that doubles as a USB DAC for your computer or phone. A Qualcomm QCC5125 Bluetooth chip and a 16-core XMOS XU316 USB chip give hi-res sound in every mode; two ESS ES9219MQ DACs, each with its own headphone amplifier, run fully balanced for up to 340mW per channel from the 4.4mm output; and a one-button mode switch, a global parametric EQ, a 0.96-inch OLED display and curved glass on both faces complete the package. Its awards include an EHA 2023 Gold Award, Headfonics Best Wireless Streamer 2023 and a VGP 2024 Summer Life Style award.

QCC5125 + XU316: hi-res in every mode

The Qualcomm QCC5125 receives Bluetooth 5.1 with LDAC, aptX Adaptive, aptX HD, aptX LL, aptX, AAC and SBC, at up to 96kHz/24-bit, and connects to two devices at once. The XMOS XU316 handles USB at up to 384kHz/32-bit and DSD256, and the BTR15 is a full MQA decoder (up to 384kHz), so MQA works in any music app. A driver-free mode (UAC 1.0) suits devices such as games consoles.

Change modes with one switch

Because the BTR15 is both a Bluetooth receiver and a USB DAC, a three-position switch on the side picks the mode for where you are listening:

• PC: a USB DAC for a computer, powered entirely by the computer.
• BT: a Bluetooth DAC and amp running on its own battery, which charges when USB is connected.
• PHONE: a USB DAC dongle for a phone, powered by its own battery (about 3 hours) so it draws nothing from your phone; USB charging is off in this mode.

A global parametric EQ

FiiO’s own PEQ algorithm and interface let you choose the exact frequencies to adjust, with their gain and bandwidth, in any mode, so you can tune the sound exactly as you like. In Bluetooth mode the EQ runs on the QCC5125’s DSP and supports LDAC and other formats up to 96kHz/24-bit; in PC and PHONE modes it runs on the XU316 up to PCM 192kHz, and switching it on or off briefly restarts the USB connection. Jazz, pop, rock and dance presets are built in.

Dual DACs, fully balanced, with an independent amp supply

Each ES9219MQ contains a HiFi Sabre quad DAC and a headphone amplifier, one chip per channel for a fully balanced design. FiiO gave the amplifiers their own low-noise, high-current power supply, built from efficient, high-PSRR low-dropout regulators and a low-noise charge pump, so they no longer share power with the DACs. The purer supply raises the balanced output by 40% to 340mW per channel into 32Ω, easily enough for portable use, and dual 45.1584MHz and 49.152MHz oscillators clock both sample-rate families.

3.5mm and 4.4mm outputs, with more power from both

Alongside the standard 3.5mm single-ended output, the BTR15 has a 4.4mm balanced output, which is more reliable and durable than 2.5mm. You don’t need the balanced output for extra power: FiiO connects the amplifiers in parallel for the 3.5mm output too, raising its power to drive low-impedance headphones better (125mW into 32Ω, 165mW into 16Ω). Two gain levels and 60 volume steps, independent of your phone’s volume and remembered between sessions, give fine control; set the phone to maximum and adjust on the BTR15 for the best sound.

A large OLED display and curved glass

Like its bigger brother the BTR7, the BTR15 has a large 0.96-inch OLED display, with room for more information and larger text: the format, sample rate, volume, battery and menu (including gain, filter, EQ, output, charge protection and brightness) are clear at a glance, in English or Chinese. For the first time FiiO uses hot-bent curved glass on both the front and back, with an aluminium alloy frame, so the BTR15 is easy and comfortable to hold, with a more three-dimensional look.

Calls, car mode and app control

In Bluetooth mode, the built-in omnidirectional microphone takes calls (not in USB DAC mode; in-line headphone remotes and microphones aren’t supported). Car mode switches the BTR15 on and off with your car’s USB power, in any mode, and it powers itself down after two minutes without a connection (adjustable in the app). The FiiO Control app adds settings such as a volume limit, Bluetooth and call volume, and how the volume buttons skip tracks, and the Bluetooth firmware updates over the air.

Comprehensive battery protection

The 550mAh battery plays for about 8 hours over Bluetooth from either output. To keep it healthy, the BTR15 can stop charging and run entirely from the computer during long USB DAC sessions, uses a durable high-temperature-resistant cell, and has a temperature sensor that adjusts or pauses charging when it gets hot. It charges in about 2 hours from a 5V 2A charger; it doesn’t fast charge.

Good to know

• Suits headphones from 8Ω to 150Ω on the 3.5mm output and 8Ω to 350Ω balanced (FiiO’s recommendation).
• Windows needs FiiO’s USB DAC driver for full hi-res USB playback; Macs, phones and the driver-free mode need no driver.
• Want more power and lossless Bluetooth? See the FiiO BTR17.
• In the box: BTR15, removable back clip, USB-C to USB-C cable, USB adapter, quick start guide and warranty card.