General specifications
Name/Model No. K19 Hardware solution DAC: ES9039SPRO*2; USB: XMOS XU316; Bluetooth decoding: QCC5125;
AMP: 8-way THX788+
Working mode USB DAC mode/Coaxial decoding mode/Optical decoding mode/HDMI decoding mode/HDMI ARC decoding mode/Bluetooth receiving mode
Color Black/Silver Weight About 1800g
Dimensions About 250x225x36.7mm Volume control type Knob/Remote control
MQA Support MQA global decoding Drive-free mode (Switch mode) Surpported
Gain Ultra high gain/Super high gain/High gain/Medium gain/Low gain Bluetooth reception (5.1) SBC/AAC/aptX/aptX LL/aptX HD/atpX Adaptive/LDAC
Display 1.30-inch TFT (240*240) fully laminated screen Display status indication Display indication: volume, gain, output mode, working mode, transmission format, sampling rate, EQ, etc.
Bluetooth format indication Surpported Sample rate indication Surpported
FIIO Control Surpported Firmware upgrade System firmware: upgrade through front panel USB interface
XMOS firmware: upgrade via front or rear panel USB interface
Bluetooth Firmware: Upgrade via FIIO Control
Remote control Supports infrared remote control (only the delivered remote control is supported) Sample rate indication
(Knob indicator light)		 Blue：44.1/48kHz
Maximum supported sampling rate USB decoding: supports up to 768kHz/32bit; DSD512 (Native)；MQA Yellow：88.2/96/176.4/192/352.8/384/705.6/768kHz
Coaxial input decoding: supports up to 192kHz/24bit; DSD64 Green：DSD64/128/256/512
Optical input decoding: supports up to 96kHz/24bit Magenta：MQA
Coaxial output: supports up to 192kHz/24bit; DSD64 Bluetooth format indicator
(Knob indicator light)		 Bule：SBC
Optical fiber output: supports up to 192kHz/24bit Cyan：AAC
HDMI decoding: supports up to 192kHz/24bit Purple：aptX/aptX LL
HDMI output: supports up to 192kHz/24bit Yellow：aptX HD
HDMI ARC decoding: supports 44.1/48kHz Green：aptX Adaptive
Adaptation impedance PO：8~150Ω White：LDAC
BAL：8~350Ω 　 　
Buttons and Interfaces
Buttons Encoder knob (volume knob with button*1+menu knob with button*1) USB interface Type-C USB (data transmission interface*2+RS232 DSP adjustment interface*1)
DC power input interface Φ6.2mm DC socket Toggle Switches DC power supply and AC power supply selector switch*1+ground selector switch*1
Digital optical input interface fiber optic socket Digital coaxial input interface RCA socket
Digital optical output interface fiber optic socket Digital coaxial output interface RCA socket
Balanced output interface Standard 4.4mm socket*1+XLR4 balanced socket*1 Headphone output interface Standard 6.35mm socket
Balanced line output interface XLR3 balanced socket Single-ended line output interface RCA socket*2
HDMI interface HDMI IN interface*1; HDMI OUT(ARC) interface*1 TRIGGER interface Standard 3.5mm headphone jack (TRIGGER IN interface*1+TRIGGER OUT interface*1)
Power parameters
Power supply Support AC 100-240V~50/60Hz; DC 15V/≥3A (choose one of the two) Battery capacity None
Audio parameters
Some performance parameters of headphone output (6.35mm output, USB DAC/Coaxial decoding/Optical decoding, Ultra high gain mode)
Output power 1 L+R≥4000mW+4000mW（16Ω，THD+N＜1%) Output impedance ＜0.6Ω（32Ω）
Output power 2 L+R≥2300mW+2300mW（32Ω，THD+N＜1%) Crosstalk ≥75dB (1kHz@32Ω)
Output power 3 L+R≥270mW+270mW（300Ω ，THD+N＜1%) THD+N ＜0.0003%(1kHz/-6dB@32Ω)
Noise floor <3.5μV (A-weighted) SNR ≥127dB (A-weighted)
Frequency response 20Hz~20kHz: Attenuation <0.2dB
20Hz~80kHz: Attenuation＜3dB		 Peak output voltage ＞22.5Vp-p
Some performance parameters of headphone output (6.35mm output, USB DAC/Coaxial decoding/Optical decoding, Super high gain mode)
Output power 1 L+R≥2400mW+2400mW（16Ω，THD+N＜1%) Output impedance ＜0.6Ω（32Ω）
Output power 2 L+R≥1250mW+1250mW（32Ω，THD+N＜1%) Crosstalk ≥75dB (1kHz@32Ω)
Output power 3 L+R≥135mW+135mW（300Ω ，THD+N＜1%) THD+N ＜0.0003%(1kHz/-4dB@32Ω)
Noise floor <3.5μV (A-weighted) SNR ≥127dB (A-weighted)
Frequency response 20Hz~20kHz: Attenuation <0.2dB
20Hz~80kHz: Attenuation＜3dB		 Peak output voltage ＞17.5Vp-p
Some performance parameters of single-ended line output (RCA output, USB DAC/Coaxial decoding/Optical decoding)
THD+N ＜0.00032%(1kHz/-0.8dB@10kΩ) SNR ≥122dB (A计权)
Crosstalk ≥110dB (1kHz@10kΩ) Noise floor ＜1.6μV（A计权）
Frequency response 20Hz~20kHz: Attenuation <0.1dB
20Hz~80kHz: Attenuation＜3dB		 Line output level 2.5Vrms  (1kHz@10kΩ)
Some performance parameters of balanced headphone output (4.4mm/XLR4 output, USB DAC/Coaxial decoding/Optical decoding, Ultra high gain mode)
Output power 1 L+R≥4000mW+4000mW（16Ω，THD+N＜1%) Output impedance ＜0.6Ω（32Ω）
Output power 2 L+R≥8000mW+8000mW（32Ω，THD+N＜1%) Crosstalk ≥120dB (1kHz@32Ω)
Output power 3 L+R≥1100mW+1100mW（300Ω ，THD+N＜1%) THD+N ＜0.0002%(1kHz/-6dB@32Ω)
Noise floor <6μV (A-weighted) SNR ≥128dB (A-weighted)
Frequency response 20Hz~20kHz: Attenuation <0.2dB
20Hz~80kHz: Attenuation＜3dB		 Peak output voltage ＞45Vp-p
Some performance parameters of balanced headphone output (4.4mm/XLR4 output, USB DAC/Coaxial decoding/Optical decoding, Super high gain mode)
Output power 1 L+R≥4000mW+4000mW（16Ω，THD+N＜1%) Output impedance ＜0.6Ω（32Ω）
Output power 2 L+R≥5000mW+5000mW（32Ω，THD+N＜1%) Crosstalk ≥120dB (1kHz@32Ω)
Output power 3 L+R≥550mW+550mW（300Ω ，THD+N＜1%) THD+N ＜0.0003%(1kHz/-9dB@32Ω)
Noise floor <6μV (A-weighted) SNR ≥126dB (A-weighted)
Frequency response 20Hz~20kHz: Attenuation <0.2dB
20Hz~80kHz: Attenuation＜3dB		 Peak output voltage ＞35.8Vp-p
Balanced line output performance parameters (XLR3, USB DAC/Coaxial decoding/Optical decoding)
THD+N ＜0.00025%(1kHz/0dB@10kΩ) SNR ≥128dB (A-weighted)
Crosstalk ≥120dB (1kHz@10kΩ) Noise floor <2.0μV (A-weighted)
Frequency response 20Hz~20kHz: Attenuation <0.1dB
20Hz~80kHz: Attenuation＜3dB		 Line output level 4.8Vrms  (1kHz@10kΩ)

PO Ultra high gain mode@2V 32Ω

 

THD+N curve 2

 

Test conditions: USB/coaxial/optical input, -4dB sine signal, Super high gain mode, 6.35 headphone output (32Ω load)

PO Super high gain mode@2V 32Ω

BAL PO Ultra high gain mode@4V 32Ω

 BAL PO Super high gain mode@4V 32Ω

BAL LO@4V  10KΩ

LO@2V 10KΩ

Frequency response curve 1

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Ultra high gain, 20Hz-20kHz, 6.35 headphone output (32Ω load)

Frequency response curve 2

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Super high gain, 20Hz-92KHz, 6.35 headphone output (32Ω load)

Frequency response curve 3

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Ultra high gain, 20Hz-20KHz, 6.35 headphone output (32Ω load)

Frequency response curve 4

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Super high gain, 20Hz-92KHz, 6.35 headphone output (32Ω load)

Frequency response curve 5

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Ultra high gain mode, 20Hz-20KHz, 4.4mm/XLR4 balanced output (32Ω load)

Frequency response curve 6

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Super high gain mode, 20Hz-92KHz, 4.4mm/XLR4 balanced output (32Ω load)

Frequency response curve 7

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Super high gain mode, 20Hz-20KHz, 4.4mm/XLR4 balanced output (32Ω load)

Frequency response curve 8

 

Test conditions: USB/coaxial/optical input, -5dB sine signal, Super high gain mode, 20Hz-92KHz, 4.4mm/XLR4 balanced output (32Ω load)

Frequency response curve 9

 

Test conditions: USB/coaxial/fiber input, -5dB sinusoidal signal, 20Hz-20KHz, RCA line output (10Ω load)

Frequency response curve 10

 

Test conditions: USB/coaxial/fiber input, -5dB sinusoidal signal, 20Hz-92KHz, RCA line output (10KΩ load)

Frequency response curve 11

 

Test conditions: USB/coaxial/optical input, -5dB sinusoidal signal, 20Hz-20KHz, XLR3 balanced line output (10KΩ load)

Frequency response curve 12

 

Test conditions: USB/coaxial/optical input, -5dB sinusoidal signal, 20Hz-92KHz, XLR3 balanced line output (10KΩ load)

THD+N curve 1

 

Test conditions: USB/coaxial/optical input, -6dB sine signal, Ultra high gain mode, 6.35 headphone output (32Ω load)

THD+N curve 3

 

Test conditions: USB/coaxial/optical input, -6dB sine signal, Ultra high gain mode, 4.4mm/XLR4 balanced headphone output (32Ω load)

THD+N curve 4

 

Test conditions: USB/coaxial/optical input, -9dB sine signal, Super high gain mode, 4.4mm/XLR4 balanced headphone output (32Ω load)

THD+N curve 5

 

Test conditions: USB/coaxial/fiber input, -0.8dB sinusoidal signal, RCA line output (10KΩ load)

THD+N curve 6

 

Test conditions: USB/coaxial/optical input, 0dB sine signal, XLR3 balanced line output (10KΩ load)