The procedure for updating firmware and filters for the three dac1xxx are the same and not really that complicated, if you have a little computer knowledge you can do it yourself.
如果您觉得自己有点电脑知识，可以试着DIY。刷成砖后果自负。不太自信的话，请联系总代理XIAUDIO解决。来回运费自付。
风险提示：
1，本说明不保证升级固件成功
2，本说明不保证能解决每台电脑的具体设置问题
3，用户自已打开产品外壳将失去保修
4，用户自己打开产品外壳有可能面临触电风险（220V高压）
5，升级固件失败可能导致产品变砖，这种情况不在保修范围之内
好，开始吧。
Step 1 is to aquire an USB to TTL Serial interface, also called an USB to RPi Serial interface. The recommended one is the FTDI TTL-232R-RPI, available at multiple sources like Digikey, Farnell and other sources for Raspberry Pi accessories. If running Windows you need to install a driver for the serial interface, follow the instruction that come with the USB interface. It should work directly with the latest version of Apple OS-X and Linux
第一步就是借一个或者买一个USB->RPi串口接口连接器（以下简称连接器），树莓派能用的就可以。淘宝有。
Step 2 is to get the right software. The dac1xxx use a serial interface so you need a terminal emulator, the recommended one for Windows is Tera Term, you can download the newest version from https://osdn.net/projects/ttssh2/. The software instructions below are for Tera Term, but the principles also apply to other Windows software, Apple OS-X and Linux.
第二步是要有对的软件，串口的终端仿真软件。推荐Windows系统用Tera Term。下载最新版就可以。https://osdn.net/projects/ttssh2/
Step 3 is to download the right firmware for your DAC from the Soekris “Downloads” page.
第三步是下载固件。官网有。
Step 4 is to connect the Soekris DAC to a computer. First disconnect power to the DAC, then open the DAC by unscrewing the screws in the bottom and slide the cover off. You then locate three pins on the board marked “GND”, “TXD” and “RXD”, they’re located close to the front. You then connect the same three pins from the USB to TTL Serial interface, the black pin to “GND”, the yellow pin to “TXD” and the orange pin to “RXD”. If you got a different USB to TTL serial interface the colors might be different. Connect the USB end to a free USB port on your computer.
第四步同把电脑和Soekris连接起来。先把Soekris断掉电源，打开产品外壳，在电路板上找到一个3针的接口，标志GND,TXD,RXD。用第一步买到的连接器，黑线接GND, 黄线接TXD, 橙线接RXD。(连接器各色各样都有，如果连接器的线的颜色不是这样配的，请与连接器供应商确认）。连接器的USB端插电脑。
Step 5 is to start and configurate the terminal emulator software, so start Tera Term. Then do “setup -> serial port”, first select the “Port”, probably “COM1” if your computer don’t have any other serial ports, then set “Baud rate” to “115200”, “Data” should be “8”, “Parity” should be “none”, “Stop” should be “1”, “Flow control” should be “none”, then click “OK”. Now do “File -> New connection”, select “Serial” and set the “Port” to the COM port as above, then click “OK”. Now the communication should be setup and you can connect power to the DAC and turn it on, be careful not to touch anything inside the DAC. You should then see a short list of status messages.
第五步打开和配置终端仿真软件。
setup -> serial port，Port, COM1
Baud rate, 115200
Data, 8
Parity, None,
Stop, 1
Flow contrla, none
这就设置完了，点OK。
然后，File -> New connection，Serial, Port, COM1,OK
然后给Soekris DAC接通电源，啥也别动。很快就能看到一串连接状态的提示。
Step 6 is to do the actual download and update. First get into the uManager by entering “+++” followed by a short pause. You should then see something like:
dac1xx1 uManager Rev 1.xx 201xxxxx FPGA Rev 1.xx Press ? for help.
第六步就是升级了。输入‘+++’后，就能看到类似这样的提示
dac1xx1 uManager Rev 1.xx 201xxxxx FPGA Rev 1.xx Press ? for help.
# Where the xx are the current revision numbers. If that is not 1.20, then download the new firmware and filters by writing:
# download
And then start a Tera Term download by doing “File -> Transfer -> XMODEM -> Send”, on the file menu, then locate the file with the DAC firmware you downloaded earlier, and for faster speed, click on the 1K option in the bottom left corner.
这一段您自己看不懂的话，就别瞎鼓捣了，把机器寄给总代理弄吧。
🙂
When done downloading do a:
# update
And click Y when asked for confirmation. Finally do a power off, short pause, then power on.
You can go into uManager again using the “+++” and check that both the uManger and FPGA are the new revisions.
输入‘+++’可以看到版本号，证实更新成功没有。
You can then disconnect power, slide the cover back on and put the screws on again, then reconnect power.
关掉电源，把Soekris DAC装回去。
That’s it, you can now enjoy the even better sound of you Soekris DAC and its new advanced anti-aliasing filters.
这就行了。开始享受音乐吧！