Name / Model No. M15 User Interface Android/Pure Music/SB DAC/Bluetooth Receiver
CPU Model Exynos 7872 14nm No. of cores  6
CPU operating frequency 2GHz (A73×2), 1.6GHz (A53×4) DAC AK4499EQ×2
Chips used SoC:Exynos 7872, DAC: AK4499EQ*2,Control Chip: XMOS XUF208,
Bluetooth chip:CSR8675,
FPGA: NDK Femtosecond crystal oscillator*2, AMP:PA2211*2+OPA1622*4+OPA1612*4,FPGA: A3P030
Special Features  Four independent system mode,Professional ADC Volume Adjustment Mode, Fully Decode (8x) the Original MQA Files, Innovative multifunctional button
Connectivity
USB TYPE C Two-way USB2.0 WiFi 2.4GHz/5GHz
Bluetooth Transmit HWA/LDAC/aptX HD/aptX/SBC Bluetooth Receive(5.0) SBC/AAC/aptX LL/aptX HD/LDAC
AirPlay Supported DLNA/NAS  UPNP protocol supported
FiiO Link Supported WiFi music transfer Supported
Display screen
Display size  5.15 inches Sreen material Corning Gorilla Glass
Display type IPS Hi-Res incell screen Number of colours 16.7M
Resolution 1440×720 Viewing angle Full view
Touchscreen 10-finger multi-touch PPI 312
Storage
RAM 3GB ROM 64GB
Storage expansion type Micro SD(TF card),Hidden TF slot ROM available to user About 52G
Maximum storage expansion  2TB (theoretically)    
Buttons and ports
Buttons Physical button + analog potentiometer volume knob + HOLD lock switch + touch screen USB Two-way TYPE C USB2.0(Charging/Data transmisson/USB DAC/Digital audio out (Usb Type C))
USB DAC 768kHz-32bit/DSD512 Digital audio out (Usb Type C) DSD64/128/256,768kHz-32bit
Headphone Out (PO) 3.5 mm headphone jack+2.5mm balanced headphone jack+4.4mm balanced headphone jack, 384kHz-32bit/DSD256 Line out(LO)  3.5 mm port(shared PO)
SPDIF Output 3.5mm port(shared PO), 384kHz-32bit/DSD128    
General
Color Black Dimensions 134*75*18mm
Weight About 307g Volume control type Analog volume
Recommended headphone impedance 16~150Ω (3.5mm headphone output) Equalizer  10-band EQ (±12dB), 8 presets+custom preset, custom EQ supported
16~600Ω (2.5mm+4.4mm balanced output)
Over-ear Headphone mode ON/OFF Gain control L/H
L/R channel balance adjustment L10~R10 (0.5dB every level)    
Power specifications
USB power adapter QC2.0/MTK PE quick charger, PD2.0 charger, DC 12V/1.5A recommended Battery capacity 7490mAh 3.8V Li-polymer battery supporting quick charge
Charging time About 3.5h (DC 12V/1.5A) Deep sleep time >1800h
Battery Life & Test Conditions
3.5mm headphone output:>15h
Over-ear Headphone mode OFF Gain L
Screen OFF Test File  MP3 44.1kHz/16bit
EQ OFF Load 32Ω
2.5mm+4.4mm balanced output:>9h
Over-ear Headphone mode OFF Gain L
Screen OFF Test File  MP3 44.1kHz/16bit
EQ OFF Load 32Ω
Others
Firmware Upgrade Supports via zip file + TF card + OTA All to DSD Supported
MQA Supports 8x MQA Navigation control Gesture control/Bottom navigation bar
Double click to wakeup Supported Power-off timers Supports sleep/Idle poweroff
In-vehicle mode M15 will power on/off automatically when vehicle engine starts/stops Pulsing Indicator Can be set to always on/breath/off, the brightness can be customized or follow the volume
Screenshot Screenshot by three-fingers swiping down and pressing both the power and the last song button Locate Currently Playing Track with One-click Supported
Custom playlist sorting Supported Third-party apps support Supports any app
Line output specifications(A-wt.)
THD+N  <0.0004% (1kHz/10kΩ) SNR >121dB
Frequency Response 5Hz~90kHz (-3dB) Noise floor <1.9μV
Channel Separation >107dB Line level 2.1V
Headphone out specifications 1(3.5mm port, A-wt.)
Output power 1 ≥285mW (16Ω/THD+N<1%)
≥405mW (Over-ear Headphone mode/16Ω/THD+N<1%)
Output impedance ≤1.4Ω
Output power 2 ≥215mW (32Ω/THD+N<1%)
≥490mW (Over-ear Headphone mode/32Ω /THD+N<1%)
THD+N  <0.0005% (1kHz/32Ω)
Output power 3 ≥31mW (300Ω/THD+N<1%)
≥70mW (Over-ear Headphone mode/300Ω/ THD+N<1%)
Separation ≥77dB
≥115dB (No load)
Frequency response 20Hz~90kHz (-3dB) Noise floor <2.1μV
<3μV (Over-ear Headphone mode)
SNR ≥121dB
≥119dB (Over-ear Headphone mode)
   
Balanced out specifications 2(2.5mm+4.4mm balanced output, A-wt.)
Output power 1 ≥420mW (16Ω/THD+N<1%)
≥370mW (Over-ear Headphone mode/16Ω/ THD+N<1%)
Output impedance ≤3Ω
Output power 2 ≥635mW (4.2V)(32Ω/THD+N<1%)
≥800mW (Over-ear Headphone mode/32Ω/ THD+N<1%)
THD+N  <0.0006% (Over-ear Headphone mode/1kHz/300Ω)
Output power 3 ≥120mW (300Ω /THD+N<1%)
≥280mW (Over-ear Headphone mode/300Ω/ THD+N<1%)
Separation ≥103dB
≥118dB (No load)
Frequency response 20Hz~90kHz (-3dB) Noise floor <3.8μV
<5.2μV (Over-ear Headphone mode)
SNR ≥122dB
≥118dB (Over-ear Headphone mode)
   
File format support
Lossless:  DSD: DSD64/128/256 (“.iso”,“.dsf”,“.dff”), DST iSO
DXD: 352.8K/24bit
APE FAST/High/Normal: 384kHz/24bit (MAX)
APE Extra High: 192kHz/24bit (MAX)
APE Insane: 96kHz/24bit (MAX)
Apple Lossless: 384kHz/32bit (MAX)
AIFF: 384kHz/32bit (MAX)
FLAC: 384kHz/32bit (MAX)
WAV: 384kHz/32bit (MAX)
WMA LOSSLESS: 96kHz/24bit (MAX)
Lossy compression:  MP3, OGG, WMA, AAC, etc

Test condition:Over-ear HP mode=OFF,Gain=H,PO output,-3dB sinusoidal signal

Test condition:Over-ear HP mode=ON,Gain=H,PO output,-3dB sinusoidal signal

Test condition:Over-ear HP mode=OFF,Gain=H,Bal output,-3dB sinusoidal signal

Test condition:Over-ear HP mode=ON,Gain=H,Bal output,-3dB sinusoidal signal

Test condition:Line output,-3dB sinusoidal signal

Test condition:Over-ear HP mode=OFF,Po output(32Ω)

Test condition:Over-ear HP mode=ON,Po output(32Ω)

Test condition:Over-ear HP mode=OFF,Bal output(32Ω)

Test condition:Over-ear HP mode=ON,Bal output(32Ω)

Test condition:Line output(32Ω)(10KΩ)