General Specifications
Name/Model K13 R2R Hardware solution SoC: ESP32-S3, DAC: FIIO-developed R2R DAC, USB decoding: XU316, AMP: OPA1642*2+TPA6120A *2
Working mode USB DAC mode/Coaxial decoding mode/Optical decoding mode/Bluetooth receiving mode Color Black/Silver
Weight About 980g Dimensions About 210x188x42mm (including feet)
Gain L/M/H Remote control Supports IR remote control (only the one included in the accessory)
Volume control Knob/Remote control FiiO Control Supported
Driver-free mode (switch mode) Supported Bluetooth receiving (5.4) SBC/AAC/LDAC
Oversampling setting OS/NOS PEQ Supported
MQA Supports MQA full decoding Knob indicator light/Top ambient light Supports customizing brightness and color, and supports always-on indication or RGB pulsing
Display 1.1-inch LCD Screen status indication Sampling rate, volume, gain, output mode, etc.
Max. supported sampling rate (PEQ=OFF) USB decoding: 384kHz/32bit; DSD256 Firmware upgrade MCU firmware: Upgrade through the side USB-C port
 
Coaxial decoding: 192kHz/24bit; DSD64 XMOS firmware: Upgrade through the side or rear USB-C port
Optical decoding: 192kHz/24bit Bluetooth firmware: Upgrade through the FIIO Control app
Adaptive impedance PO: 8~350Ω 　 　
BAL: 8~350Ω 　 　
Buttons and Ports
Knob Volume knob with button*1+Menu knob with button*1 USB port Type-C USB*2 (Data transmission port)
Digital coaxial input port RCA plug Digital optical input port Optical port
Balanced output port Standard 4.4mm port Headphone output port Standard 6.35mm port
Balanced line output port XLR3 balanced port Single-ended line output port RCA port*2
Toggle switch Power toggle switch 　 　
Power Supply Parameters
Power supply AC 100-240V~50/60Hz; DC 12V/≥2.5A (either-or) Battery capacity No battery
Audio Parameters
Performance and parameters of headphone output (6.35mm out, USB DAC/Coaxial decoding/Optical decoding, High gain, OS mode)
Output power 1 L+R≥1200mW+1200mW (16Ω, THD+N＜1%, 4.4Vrms ) Output impedance ＜0.4Ω (32Ω)
Output power 2 L+R≥1220mW+1220mW (32Ω, THD+N＜1%, 6.2Vrms ) Crosstalk ≥77dB (1kHz@32Ω)
Output power 3 L+R≥150mW+150mW (300Ω , THD+N＜1%, 6.7Vrms ) THD+N About 0.0173% (1kHz/-6dB@32Ω)
Noise floor ＜9.4μV (A-weighted) SNR ≥117dB (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥108dB
20Hz~80kHz: attenuation＜2.9dB Peak output voltage ＞19Vp-p
Performance and parameters of headphone output (6.35mm out, USB DAC/Coaxial decoding/Optical decoding, Medium gain, OS mode)
Output power 1 L+R≥660mW+660mW (16Ω, THD+N＜1%, 3.3Vrms ) Output impedance ＜0.4Ω (32Ω)
Output power 2 L+R≥340mW+340mW (32Ω, THD+N＜1%, 3.3Vrms ) Crosstalk ≥77dB (1kHz@32Ω)
Output power 3 L+R≥35mW+35mW (300Ω , THD+N＜1%, 3.3Vrms ) THD+N About 0.0173% (1kHz/-6dB@32Ω)
Noise floor ＜5.0μV (A-weighted) SNR ≥117dB (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥108dB
20Hz~80kHz: attenuation＜2.9dB Peak output voltage ＞9Vp-p
Performance and parameters of headphone output (6.35mm out, USB DAC/Coaxial decoding/Optical decoding, Low gain, OS mode)
Output power 1 L+R≥165mW+165mW (16Ω, THD+N＜1%, 1.6Vrms ) Output impedance ＜0.4Ω (32Ω)
Output power 2 L+R≥85mW+85mW (32Ω, THD+N＜1%, 1.6Vrms ) Crosstalk ≥77dB (1kHz@32Ω)
Output power 3 L+R≥10mW+10mW (300Ω , THD+N＜1%, 1.6Vrms ) THD+N About 0.0179% (1kHz/0dB@32Ω)
Noise floor ＜4.0μV (A-weighted) SNR ≥113dB (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥106dB
20Hz~80kHz: attenuation＜2.9dB Peak output voltage ＞5Vp-p
Performance and parameters of single-ended line output (RCA out, USB DAC/Coaxial decoding/Optical decoding, OS mode)
THD+N About 0.0192% (1kHz/-6dB@10KΩ) SNR ≥116dB (A-weighted)
Crosstalk ≥104dB Noise floor ＜4.3uV (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥108dB
20Hz~80kHz: attenuation＜2.9dB Line output level 2.6Vrms (1kHz@10kΩ)
Performance and parameters of balanced headphone output (4.4mm out, USB DAC/Coaxial decoding/Optical decoding, High gain, OS mode)
Output power 1 L+R≥1200mW+1200mW (16Ω, THD+N＜1%, 4.4Vrms ) Output impedance ＜1Ω (32Ω)
Output power 2 L+R≥2400mW+2400mW (32Ω, THD+N＜1%, 8.8Vrms ) Crosstalk ≥110dB (1kHz@32Ω)
Output power 3 L+R≥600mW+600mW (300Ω , THD+N＜1%, 13.5Vrms ) THD+N About 0.0173% (1kHz/-6dB@32Ω)
Noise floor ＜18μV (A-weighted) SNR ≥115dB (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥109dB
20Hz~80kHz: attenuation＜2.9dB Peak output voltage ＞38Vp-p
Performance and parameters of balanced headphone output (4.4mm out, USB DAC/Coaxial decoding/Optical decoding, Medium gain, OS mode)
Output power 1 L+R≥1200mW+1200mW (16Ω, THD+N＜1%, 4.4Vrms ) Output impedance ＜1Ω (32Ω)
Output power 2 L+R≥1300mW+1300mW (32Ω, THD+N＜1%, 6.5Vrms ) Crosstalk ≥112dB (1kHz@32Ω)
Output power 3 L+R≥145mW+145mW (300Ω , THD+N＜1%, 6.6Vrms ) THD+N About 0.0173% (1kHz/-6dB@32Ω)
Noise floor ＜8.0μV (A-weighted) SNR ≥118dB (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥109dB
20Hz~80kHz: attenuation＜2.9dB Peak output voltage ＞19Vp-p
Performance and parameters of balanced headphone output (4.4mm out, USB DAC/Coaxial decoding/Optical decoding, Low gain, OS mode)
Output power 1 L+R≥610mW+610mW (16Ω, THD+N＜1%, 3.1Vrms ) Output impedance ＜1Ω (32Ω)
Output power 2 L+R≥330mW+330mW (32Ω, THD+N＜1%, 3.2Vrms ) Crosstalk ≥110dB (1kHz@32Ω)
Output power 3 L+R≥35mW+35mW (300Ω , THD+N＜1%, 3.3Vrms ) THD+N About 0.0183% (1kHz/-6dB@32Ω)
Noise floor ＜5.1μV (A-weighted) SNR ≥116dB (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥108dB
20Hz~80kHz: attenuation＜2.9dB Peak output voltage ＞9.5Vp-p
Performance and parameters of balanced line output (XLR3, USB DAC/Coaxial decoding/Optical decoding, OS mode)
THD+N About 0.0185% (1kHz/-6dB@10KΩ) SNR ≥117dB (A-weighted)
Crosstalk ≥113dB Noise floor ＜7.3uV (A-weighted)
Frequency response 20Hz~20kHz: attenuation＜0.2dB Dynamic range ≥109dB
20Hz~80kHz: attenuation＜2.9dB Line output level 5.3Vrms (1kHz@10kΩ)