The Q15 sits at the top of FiiO's portable DAC and headphone amplifier range, combining the AKM AK4191EQ and AK4499EX DAC chipset with a powerful amplifier section capable of desktop-grade output levels. It bridges the gap between portable convenience and the performance normally associated with full-size desktop components.
DAC and Signal Processing
At the heart of the Q15 is AKM's AK4499EX DAC paired with the AK4191EQ digital filter chip. The AK4499EX is AKM's flagship mono DAC, featuring complete separation of digital and analogue circuitry. The AK4191EQ handles digital filtering ahead of the conversion stage, allowing the AK4499EX to operate in a dedicated analogue-only mode. The XMOS XU316 USB processor manages the USB input, supporting PCM at up to 768kHz/32-bit and native DSD512 decoding. MQA Full Decoding is also supported across USB, Bluetooth and coaxial inputs.
The power supply section uses a 15-way digital-analogue configuration with 21 low-noise LDOs and 35 tantalum capacitors, minimising noise coupling between the digital processing and analogue output stages.
Output and Amplification
The Q15 provides both a 3.5mm single-ended output and a 4.4mm balanced output. Five gain levels (Ultra High, Super High, High, Medium and Low) accommodate headphones and IEMs across a wide impedance range: 8-150 ohms on the single-ended output and 8-350 ohms balanced. In Battery Mode the balanced output delivers 1060mW into 32 ohms, while switching to Desktop Mode (USB-powered) raises this to 1610mW into 32 ohms. The single-ended output provides 625mW into 32 ohms. SNR measures at or above 123dB (A-weighted) and THD+N is below 0.0005% at 1kHz.
Connectivity and Wireless
The Q15 accepts audio from three input types: USB from a computer or smartphone, coaxial S/PDIF from a CD player or transport (supporting PCM up to 192kHz/24-bit), and Bluetooth 5.1 via the Qualcomm QCC5125 chipset. Supported wireless codecs include SBC, AAC, aptX, aptX LL, aptX Adaptive, aptX HD and LDAC at up to 24-bit/96kHz.
Phone Mode allows the Q15 to draw power from its own internal 5500mAh battery rather than draining the connected device, giving approximately nine hours of use from the 3.5mm output. A built-in global parametric equaliser with seven presets and three user-configurable settings is accessible across all input modes. A 1.30-inch full-colour TFT display shows the active input, bit depth, sample rate, volume and battery level.