General Specifications
Name/Model DM15 R2R Hardware Scheme

master control: GD32F305RET6, op amp: SGM8262 * 2,

DAC:Feiao Self-developed R2R DAC, Bluetooth: QCC3095,

USB chip: SPV5048
working mode CD playback/USB DAC mode/Bluetooth transmitter mode
color White/Black/Red/Silver Weight about 471.5g
Product Size about 144x 137x 25.5mm (not including foot pads and knobs) Volume Control Type button control
screen 0.96 inch (80x 160)LCD display bald head custom bald head
Recommended Adapt Headset Impedance PO:8~350Ω movement custom movement
BAL:8~350Ω 　 　
Keys and Interfaces
key

Power key * 1; Stop key * 1; Play/Pause key * 1; Previous * 1;

Next song * 1;EQ button * 1;

 USB

Type-C USB2.0 * 1 (data transfer) +

Type-C POWER IN * 1 (charging/independent power supply interface)
Headphone output interface standard 3.5mm socket balanced output interface standard 4.4mm socket
Linear Output Interface standard 3.5mm socket Balanced Linear Output Interface standard 4.4mm socket
coaxial output interface standard 3.5mm socket (multiplexed with LO port) fiber output interface standard 3.5mm socket (multiplexed with LO port)
ripple switch input switch button * 1 + output switch button * 1 + BASS switch * 1 + ESP switch * 1 + D.MODE switch * 1 　 　
Features
Bluetooth Transmitter (5.4) SBC/aptX/aptX-HD/aptX-LL/aptX-Adaptive Operation mode button/knob operation
BASS BASS OFF/1/2 Timing Shutdown support
EQ Adjustment built-in 8 kinds of preset EQ Drive-free mode support
Maximum supported sampling rate USB DAC: Supports up to 384kHz/32bit;DSD256(Native) Firmware Upgrade USB Upgrade/Local Upgrade
coaxial output: maximum support 192kHz/24bit; 　 　
fiber output: support up to 96kHz/24bit; 　 　
Power Parameters
Power support PD2.0 and PD3.0 fast charge charging time about 2 hours (PD3.0 fast charge)
CD Endurance and Test Conditions:
3.5mm headphone output: 7 hours
Volume 59 BASS OFF
screen status Close ESP ON
EQ Close D.MODE OFF
load 32 Ω 　 　
4.4mm balanced output: 7 hours
Volume 53 BASS OFF
screen status Close ESP ON
EQ Close D.MODE OFF
load 32 Ω 　 　
USB decoding life and test conditions:
3.5mm headphone output: 11 hours
Volume 59 BASS OFF
screen status Close ESP OFF
EQ Close D.MODE OFF
load 32 Ω 　 　
4.4mm balanced output: 10.5 hours
Volume 53 BASS OFF
screen status Close ESP OFF
EQ Close D.MODE OFF
load 32 Ω 　 　
Audio Parameters
headphone output part performance parameters (3.5mm output, USB DAC,OS mode, Taiwan mode)
output power L+R≥575mW+575mW (16Ω,THD+N<1%,3.1Vrms) output impedance <1Ω
L+R≥315mW+315mW (32Ω,THD+N<1%,,3.2Vrms) channel separation ≥ 72dB
L+R≥35mW+35mW (300Ω,THD+N<1%,3.3Vrms) peak output voltage 9.5Vp-p
signal-to-noise ratio ≥ 111dB (A-weighted) distortion plus noise <0.025%(1kHz/-6dB @ 32Ω)
frequency response 20Hz ~ 80kHz: Attenuation <2.9dB bottom noise <8.7uV(A weight)
20Hz ~ 20KHz: attenuation <0.2dB dynamic range ≥ 106dB (A-weighted)
headphone output part performance parameters (3.5mm output, USB DAC,OS mode)
output power L+R≥405mW+405mW (16Ω,THD+N<1%,2.5Vrms) output impedance <1Ω
L+R≥220mW+220mW (32Ω,THD+N<1%,,2.7Vrms) channel separation ≥ 72dB
L+R≥25mW+25mW (300Ω,THD+N<1%,2.8Vrms) peak output voltage 7.9Vp-p
signal-to-noise ratio ≥ 111dB (A-weighted) distortion plus noise <0.025%(1kHz/-6dB @ 32Ω)
frequency response 20Hz ~ 80kHz: Attenuation <2.9dB bottom noise <7.5uV(A weight)
20Hz ~ 20KHz: attenuation <0.2dB dynamic range ≥ 106dB (A-weighted)
balanced headphone output part performance parameters (4.4mm output, USB DAC,OS mode, Taiwan mode)
output power L+R≥480mW+480mW (16Ω,THD+N<1%,2.8Vrms) output impedance <1.5Ω
L+R≥1150mW+1150mW (32Ω,THD+N<1%,6.1Vrms) channel separation ≥ 100dB
L+R≥145mW+145mW (300Ω,THD+N<1%,6.6Vrms) peak output voltage 18.8Vp-p
signal-to-noise ratio ≥ 112dB (A-weighted) distortion plus noise <0.025%(1kHz/-6dB @ 32Ω)
frequency response 20Hz ~ 70kHz: Attenuation <3dB bottom noise <14.7uV(A weight)
20Hz ~ 20KHz: attenuation <0.3dB dynamic range ≥ 107dB (A-weighted)
balanced headphone output part performance parameters (4.4mm output, USB DAC,OS mode)
output power L+R≥545mW+545mW (16Ω,THD+N<1%,2.9Vrms) output impedance <1.5Ω
L+R≥815mW+815mW (32Ω,THD+N<1%,5.1Vrms) channel separation ≥ 100dB
L+R≥100mW+100mW (300Ω,THD+N<1%,5.5Vrms) peak output voltage 15.8Vp-p
signal-to-noise ratio ≥ 112dB (A-weighted) distortion plus noise <0.025%(1kHz/-6dB @ 32Ω)
frequency response 20Hz ~ 80kHz: attenuation <2.9dB bottom noise <12.7uV(A weight)
20Hz ~ 20KHz: attenuation <0.2dB dynamic range ≥ 107dB (A-weighted)
linear headphone output part performance parameters (3.5mm output, USB DAC,OS mode, Taiwan mode)
distortion plus noise <0.025%(1kHz/-6dB @ 10KΩ) signal-to-noise ratio ≥ 111dB(A-weighted)
channel separation ≥ 100dB bottom noise <9.2uV(A weight)
frequency response 20Hz ~ 80kHz: attenuation <2.9dB Line Output Level 3.3Vrms(1KHz@10kΩ)
20Hz ~ 20KHz: attenuation <0.2dB dynamic range ≥ 106dB (A-weighted)
linear headphone output part performance parameters (3.5mm output, USB DAC,OS mode)
distortion plus noise <0.025%(1kHz/-6dB @ 10KΩ) signal-to-noise ratio ≥ 111dB(A-weighted)
channel separation ≥ 100dB bottom noise <7.9uV(A weight)
frequency response 20Hz ~ 80kHz: attenuation <2.9dB Line Output Level 2.8Vrms(1KHz@10kΩ)
20Hz ~ 20KHz: attenuation <0.2dB dynamic range ≥ 106dB (A-weighted)
balanced linear headphone output part performance parameters (4.4mm output, USB DAC,OS mode, Taiwan mode)
distortion plus noise <0.025%(1kHz/-6dB @ 10KΩ) signal-to-noise ratio ≥ 112dB (A-weighted)
channel separation ≥ 108dB bottom noise <15.6uV(A weight)
frequency response 20Hz ~ 80kHz: attenuation <2.9dB Line Output Level 6.5Vrms(1KHz@10kΩ)
20Hz ~ 20KHz: attenuation <0.2dB dynamic range ≥ 107dB (A-weighted)
balanced linear headphone output part performance parameters (4.4mm output, USB DAC,OS mode)
distortion plus noise <0.024%(1kHz/-6dB @ 10KΩ) signal-to-noise ratio ≥ 112dB (A-weighted)
channel separation ≥ 108dB bottom noise <13uV(A weight)
frequency response 20Hz ~ 80kHz: attenuation <2.9dB Line Output Level 5.4Vrms(1KHz@10kΩ)
20Hz ~ 20KHz: attenuation <0.2dB dynamic range ≥ 107dB (A-weighted)
headphone output part performance parameters (3.5mm output, CD,OS mode, Taiwan mode)
output power L+R≥575mW+575mW (16Ω,THD+N<1%,3.1Vrms) output impedance <1Ω
L+R≥315mW+315mW (32Ω,THD+N<1%,,3.2Vrms) channel separation ≥ 72dB
L+R≥35mW+35mW (300Ω,THD+N<1%,3.3Vrms) peak output voltage 9.5Vp-p
signal-to-noise ratio ≥ 110dB (A-weighted) distortion plus noise <0.028%(1kHz/0dB @ 32Ω)
dynamic range ≥ 94dB (A-weighted) bottom noise <9.7uV(A weight)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB 　 　
headphone output part performance parameters (3.5mm output, CD,OS mode)
output power L+R≥405mW+405mW (16Ω,THD+N<1%,2.5Vrms) output impedance <1Ω
L+R≥220mW+220mW (32Ω,THD+N<1%,,2.7Vrms) channel separation ≥ 72dB
L+R≥25mW+25mW (300Ω,THD+N<1%,2.8Vrms) peak output voltage 7.9Vp-p
signal-to-noise ratio ≥ 109dB (A weight) distortion plus noise <0.027%(1kHz/0dB @ 32Ω)
dynamic range ≥ 94dB (A-weighted) bottom noise <8.5uV(A weight)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB 　 　
balanced headphone output part performance parameters (4.4mm output, CD,OS mode, Taiwan mode)
output power L+R≥480mW+480mW (16Ω,THD+N<1%,2.8Vrms) output impedance <1.5Ω
L+R≥1150mW+1150mW (32Ω,THD+N<1%,6.1Vrms) channel separation ≥ 100dB
L+R≥145mW+145mW (300Ω,THD+N<1%,6.6Vrms) peak output voltage 18.8Vp-p
signal-to-noise ratio ≥ 112dB (A-weighted) distortion plus noise <0.030%(1kHz/0dB @ 32Ω)
dynamic range ≥ 94dB (A-weighted) bottom noise <14uV(A-weighted)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB 　 　
balanced headphone output part performance parameters (4.4mm output, CD,OS mode)
output power L+R≥490mW+490mW (16Ω,THD+N<1%,2.8Vrms) output impedance <1.5Ω
L+R≥810mW+810mW (32Ω,THD+N<1%,5.1Vrms) channel separation ≥ 100dB
L+R≥100mW+100mW (300Ω,THD+N<1%,5.5Vrms) peak output voltage 15.8Vp-p
signal-to-noise ratio ≥ 110dB (A-weighted) distortion plus noise <0.029%(1kHz/0dB @ 32Ω)
dynamic range ≥ 94dB (A-weighted) bottom noise <13.6uV(A weight)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB 　 　
Linear headphone output part performance parameters (3.5mm output, CD,OS mode, Taiwan mode)
distortion plus noise <0.028%(1kHz/0dB @ 10KΩ) signal-to-noise ratio ≥ 110dB(A-weighted)
channel separation ≥ 100dB bottom noise <9.6uV(A weight)
dynamic range ≥ 94dB (A-weighted) Line Output Level 3.3Vrms(1KHz@10kΩ)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB 　 　
Linear headphone output part performance parameters (3.5mm output, CD,OS mode)
distortion plus noise <0.027%(1kHz/0dB @ 10KΩ) signal-to-noise ratio ≥ 110dB(A-weighted)
channel separation ≥ 100dB bottom noise <8.5uV(A weight)
dynamic range ≥ 94dB (A-weighted) Line Output Level 2.8Vrms(1KHz@10kΩ)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB 　 　
balanced linear headphone output part performance parameters (4.4mm output, CD,OS mode, Taiwan mode)
distortion plus noise <0.029%(1kHz/0dB @ 10KΩ) signal-to-noise ratio ≥ 110dB (A-weighted)
channel separation ≥ 104dB bottom noise <18.4uV(A weight)
dynamic range ≥ 94dB (A-weighted) Line Output Level 6.5Vrms(1KHz@10kΩ)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB 　 　
balanced linear headphone output part performance parameters (4.4mm output, CD,OS mode)
distortion plus noise <0.029%(1kHz/0dB @ 10KΩ) signal-to-noise ratio ≥ 110dB (A-weighted)
channel separation ≥ 104dB bottom noise <15.8uV(A weight)
dynamic range ≥ 94dB (A-weighted) Line Output Level 5.4Vrms(1KHz@10kΩ)
frequency response 20Hz ~ 20KHz: attenuation <1.5dB