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1. To maintain a high standard of circuit design and selection and to leave as much as possible  space for DIY audiophiles . The PCB uses high-quality thick gold four-layer design, access to high noise and output dynamic range. Thickness of the board is  2mm, four copper thickness are 2oz (ounces). The gold layer is 5u-inch thick.
2. Full soft control program, the motherboard controller has built-in VFD2002 display driver and ALPS EC11-type rotary encoder driver. it can be extended through the motherboard interface to an external VFD display and rotary switch to support the volume adjustment 0 to 16 gradient.
3. The user can use the ALPS rotary encoders to signal input rotation, mode setting, volume adjustment and so on.
4. The display uses the Japanese two-leaf electron (Futaba) vacuum fluorescent display, display exceptionally well. The display information is intact, it can display the current signal, filter mode, sampling rate and other informations.
5. At the same time, in the absence of the screen, you can use the three buttons on the motherboard to signal selection and volume adjustment (0 ~ 16 adjustable), and the motherboard has 21 LED indicators, you can see the complete and necessary information    
6. You can add  the USB DSD module, USB module is  the world's top-level Italian Amanero USB DSD PCM combo384 module. it can overkill  PCI sound card and is comparable to the high-priced dial.
7. USB supports 32bit PCM 44.1K 48K 88.2K 96K 176.4K, 192K, 352.8K 384K.
8. DSD supports DSD64, DSD128, DSD256, DSD512
9. Windows supports 32/64-bit XP / Vista / win7 / win8 requires the installation of proprietary drivers (support KS / Wasapi / WDM / ASIO).
10. Mac OS 10.6+ and Linux UAC2 no need driving.
11. Good decoder, the power must be the focus of the design, so we use a multi-channel power supply.The  9018 core, digital, analog, I / V conversion & LPF, control, display and other functional components all have a separate power supply , reducing theinterference between the various blocks, we strive to do the best sound. The PCB is in strict accordance with the figures, analog block and single-point grounding.
12. The regulator uses the LT1763, an ultra-low noise regulator from Linear Technology. The regulator  has as low as 20uVrms output noise in the 10Hz ~ 100KHz band, the output current can be up to 500mA, the performance is extremely good. The board also designed to have another alternative regulator,  you can use the United States National Semiconductor NS LP38798 to replace the LT1763. LP38798 is a  the regulator with very abnormal performance, 10Hz ~ 100KHz bandwidth, the output noise is as low as 5uVrms. Output current can be up to 800mA, and in the 10KHz output ripple compression ratio PSRR is 90dB. (Usually at 1KHz if the PSRR to 70dB already belongs to the high ripple rejection ratio of the regulator) 100KHz 60dB.
13. Analog output section, using a single op amp design, you can use the op amp seat,which is easy to replace the op amp.
14. ES9018 crystal is designed in two sizes, one is the size of common DIP14 rectangular strip four crystal, the other is the type of Chip-type Chip-CCHD-9XX pad.
15. Coaxial, BNC, AES / EBU input circuits are using Murata Murata digital transformer, they perfectly support 192K spdif input,  these bandwidth is much higher than the common PE-65612, DV709 Spdif receiver part  uses high-sensitivity, high-speed RS422 receiver, signal reduction accuracy, better than the common 74HCU04 circuit.
16. The fiber head is a 25M ultra-high-speed head.
17. Motherboard input and output terminals are intact, covering a wide range of commonly used audio equipments, most of the interfaces.
18. There are six kinds of input terminals: coaxial, BNC, optical fiber, AES / EBU, USB, I2S, these 6 signal inputs can be selected through the display with the rotary switch. (Signal can be all access, which is needed, which channel will be selected in the display, and with memory function, it will automatically restore the last memory configurationwhen booting).
19. Coaxial, optical, BNC, AES / EBU all perfectly support 44K, 88.2K, 96K, 176.4K, 192K sampling rate, and accurate display on the screen.
20. USB supports DSD64, DSD128, DSD256, DSD512, PCM supports up to 384K.
21. Output terminal has 2 specifications: XLR full balanced output (true balance) (5Vrms), RCA unbalanced output (2Vrms).

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Many users concerned about the parameters of the problem. This kit is not tested with a professional AP tester. Only the ASUS XONAR D2 PCI sound card to do about RMAA test (and 1212M considerable), because the limitations of the sound card back to the circuit with the AP tester can not be compared, but the RMAA back to the recorded test parameters can basically reflect the kit Level.

The figure is the machine's frequency response curve, we can see that, from 0 ~ 20K, the frequency curve is very smooth, no abnormal peaks

The figure above shows the noise level at the output. It can be seen that the higher peak appears below 1K, but the maximum did not exceed-120dB,  the noise output(higher than 1K) is below  -140dB . the high peak in below 1K relates to  test environment(computer sound card recording and testing of audio signal line 8 yuan(RMB) a harsh,even in such a bad environment,it can have such a high performance)

The figure is the dynamic response spectrum, the peak appears in the 100Hz, this is still with the test environment,  the index is very good in higher than the 1K frequency,, dynamic range is more than -140dB, in accordance with the level of recording sound card,there is no -140dB, But the software reflects that it has been up to  the limits of the sound card.

The figure is 60Hz and 7KHz frequency intermodulation distortion spectrum, you can see that intermodulation distortion is very low.

the three versions: