TOPPING DX1 AK4493S Desktop DAC & Headphone Amplifier

Introduction:
DX1 is a small desktop computer that supports USB input, amp + Line out output.
DX1 is a desktop audio solution for miniaturization or limited budget, it is a complement to D10s and D10 Balanced (D10 series has no built-in amp and DX1 has no interface function)
Spec:
DX1 DAC Parameters (USB ln@44. 1kHz )
THD+N @1kHz (A-wt)<0.0002 %
00 THD @20-20kHz 90kBW<0.0006%
SNR @1kHz (A-wt):120dB
Dynamic range @1kHz (A-wt):120dB
Frequency Response:
20Hz-20kHz (±0.3dB)
20Hz-40kHz (±0.7dB)
Output Level:2.0Vrms @0dBFS
Noise (A-wt) <2.0uVrms
Channel Crosstalk @1kHz:-112dB
Channel Balance:0.3 dB
Output Impedance:22Ω
DX1 Headphone Amplifier Specifications
THD+N @1kHz ( A-wt)
<0.0003% @ Output=200mW (32Ω)
<0.0002% @Output=4 5mW (300Ω)
THD @20-20kHz 90kB W
<0.003% @Output=200mW (32Ω)
<0.001% @Output=45mW (300Ω)
SNR @MAX OUT 1kHz ( A-wt):118dB
Dynamic Range @1kHz (A-wt):118dB
Frequency Response
20Hz 20kHz (±0.3dB)
20Hz-40kHz (±0.7dB)
Output Level
2.2Vpp @G=L
11Vpp @G=H
Noise ( A-wt)< 1.0uVrms
Channel Crosstalk @ 1kHz:-86dB
Gain:-2dB (Vrms/FS) @G=L 
        12dB (Vrms/FS) @G=H
Output Impedance< 0.5Ω
Output Power
280mW X 2 @32Ω THD+N<0.1 %
190mW X 2 @64Ω THD+N<0.1 %
51mW X 2 @300Ω THD+N<0.1 %
Load Impedance>8Ω