FAQ:
　

Index:
1,Why most of our power amps have large power output (250W/8 ohm)?
2, What 's different of the power supply between NFB series?
3,What's different between Diamond Differential amp and the Diamond buffer ?
4,
5,The NFB-10 setting to variable mode will stop ACSS working?
6,DSP-1 Jumpers setting.
7,Do I need the extern PSU for Digital Interface?
8,Which input is the best between USB,coaxial and optical?
9,What's different between the DIR9001 and WM8805 modules?
10, Can I exchange the DIR9001 and WM8805 easy?
11, What's different between the Reference 7.1 and NFB9 ?
12, After shipping , why we want to wait 2-3 days send the DHL track number to customers?
　

1,Why most of our power amps have large power output (250W/8 ohm)?
The amp with Large power output do not mean it must working in loud sound.
It just mean it had much  output current so can drive the speakers work well. It can let the speakers get the best performance.
In face, most of our amp user only use in home, the output usually is less than 5WRMS , but this is not fixed for the music, some time it can eat 10X times power , and transistor amp best output is less than 20% full power output , so the large power amp is needful. Just for better sound not for loud.

2, What 's different of the power supply between NFB series?

　

             Discrete PSU ( Linear)                                                            Discrete PSU (Class A)
              

3,What's different between Diamond Differential amp and the Diamond buffer ?

             I read on forum, some people maybe confounded the diamond Differential amp and the Diamond buffer . See the circuits of below please.
           Diamond Differential amp                                       Diamond buffer
                                                    

5,The NFB-10 setting to variable mode will stop ACSS working?

No. The NFB-10 always working with ACSS in every modes , in variable output mode, the ACSS signal just separated between ACSS modules and the ACSS output sockets , so can't degrade on sound quality, just choice what mode you wanting .

7,Do I need the extern PSU for Digital Interface?

        The Digital Interface had power supply by USB, the extern PSU maybe can improve on sound quality but depend on users justice , but in follow case you maybe get the extend PSU together is better.
        A, Purchase the version A ( had coaxial input ) and it place far away the PC, without USB power supply.
        B, The PC had bad power supply , extern PSU can improve the sound definitely.   Usually the best well know brand notebook/PC , like IBM, MacBook ect. had clear power supply. But some notebooks  and  PC had dirty power supply.

8,Which input is the best between USB, coaxial and optical?

        In theory, Coaxial is best of them, if the source output design is same level.
        In fact, the source output design most have not same level, and coaxial and optical much depend on the cable quality (especial coaxial transmit), so there is better compare by self.

9,What's different between the DIR9001 and WM8805 modules?

       Both modules have same jitter , but the specs not mean the sound. The DIR9001 have most neutral sound, up to 96KHz support. The WM8805 have slight warmer and smoother sound ,up to 192KHz support. If you bother how to choice one of them, you can order both at same time, or order the default (WM8805) at first, in future if you want more neutral sound , just order the DIR9001 module.

10, Can I exchange the DIR9001 and WM8805 easy?

       The exchange is so easy. Just follow the steps as below:
         1, Power off the gear, pull off the power cable.
         2, take off the cover of the chassis.
         3, Find the DIR module in the inside, take off the one screw on the DIR module.
         4, Carefully pull off the original module.
         5, Carefully push into the new module and put back the screw and the cover of the chassis.
         6, Push back the power cable and power on the gear, if there is no smoke and have music ,it mean you have not made wrong and can enjoy the music again.

11, What's different between the Reference 7.1 and NFB-9 ?

       There is difficult to explain but in short words,  The reference 7.1 sound is dead neutral , a monitor sounding , it can easy show how good or how bad of the recorders, reveal the flaws of the source . The NFB-9 sound is slight on warm and smooth side but still neutral sounding . It can cover some flaws of the source and the bad recorders.