I have been playing for the past few days with this DAC and I like it (HD650 and HE400),sounds little metallic by itself but you can counter this with tube amp ,I was looking for more 3D /holographic sounding DAC so this one will go back ,otherwise it's pretty good DAC with even better amp ,as for specs ...
· X1 Pro 24BIT MINI USB DAC
X1 Pro 24bit mini USB DAC can be used as :
· High quality PC/USB soundcard/DAC
· High quality headphone amp
· high quality pre-amp
Modular functional design , full expansion interface equipped.
External power adapter ,less interference.
3) Concave button design , fit your fingers more comfortable , two-color LED indicator display.
4) Modular functional design , full expansion interface.
5) High quality KOA, WIMA ,NICHICON components used.
Input SPIF×1 Coaxial*1 USB（1.0）×1 Analog RCA *1
Output Analog RCA*1 6.5mm headphone*1
Frequency 20HZ---20KHZ (+/-0.5dB)
THD + N <0.00227% (-92.8dB)@20khz Unweight
Headphone output 0.05%
Input choose USB/SPDIF ×1 Analog/ digital ×1
Headphone output P－PMAX：10V
Headphone output impedance : 32 ohm---600 ohm
Line output 2Vrms
Power input DC12－18V 500mA
Size （chassis ） 135*51*170 (mm)
Now the X1MK2 has been upgraded to the Aune X1 "Pro" DAC: (Limited to only a few world wide for the first batch)
Upgrades include USB section from PCM2707 to 24BIT TE7022, the entire USB section of the entire unit can reach to 24BIT which allows for pristine and uninterrupted performance.
Aune X1 Pro functions :
1. 24BIT USB DAC function —this function is the upgrade of Pro version.
The unit adopts TE TE7022 to reach computer voice signal receiving sections.
Through the USB, interface receives the computer signal directly, using I2S output via the same as TI PCM1793 produced by DAC chip for decoding, and then to the Line Out or expander ear sound output.
2. 24bit/192K DAC:
The unit is provided with a coaxial ( Coaxial ) digital input. Using the ratio as low as 5PS WM8805 receiver chip, the coaxial line receives signal from the CD/DVD and the 24BIT player digital signal can be passed to the machine's DAC chip PCM1793 for decoding, like general CD/DVD turntable sound marked ascending, and can pass through the Line Out output connection to the external amplifiers or through the expander ear output to the headset to enjoy music. This machine is a super cost-effective 24BIT/192K scheme
3. Headphone AMP:
Ear expanding/Headphone section adopts OP+BUF frame line and can improve direct DAC transmissions, but also external larger equipment using Omron signal dedicated relay (Relay ) signal set change, by Line In ( RCA a ) input external analog signal (Analog ) such as CD/ DVD machine. Output, the existing DAC analog signal, and even an IPod sound output (requires adapter through the Lineout output signal )
4 . Pre-AMP:
This feature of Aune X1 Pro has special functionality and can independently volume levels. LINE IN to line OUT volume control, and may choose to DAC output volume controllable, all controlled by single chip microcomputer