Btw, I had a long series of exchanges with Shenzhen Audio for the past 2 weeks due to some random muffled sound problem with my SU-6. Although many emails, I'm happy that they have been very responsive so far. I copied and paste below one of my emails that more or less describes the problem. Basically, I discovered this when random PC boot ups produced this muffled sound. After a reboot or 2, or 3, it will be ok. In the exchanges with them, I have gone through the steps in my above post with numerous installing/uninstalling multiple versions because those versions mentioned were all not in the download folder. Finally, only to find that my unit is already on FW v2.21 haha... I did reflash 2.21 but the problem is still there.
In my test described below, I just unplug/plug the USB cable to simulate "new" connection. I hope I'm right about the HDMI of my unit. Now they have diverted me to Singxer directly... awaiting their response.
I just saw Singxer's website itself and v4.13 is there:
http://www.singxer.com/col.jsp?id=108
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I have recorded the video recorded from speakers. In the video, I unplug USB and plug in USB a few times. You can hear 2 of the times the music becomes total treble loss. There is also distortion at the 37-second point in the video until about 45 seconds. In the last time unplug USB and plug in USB, the music becomes clear again. Video in google drive below:
https://drive.google.com/file/d/1jg_k82-jy6nuhVwBrY-gKO08J93xGuiY/view?usp=sharing
I have also done some testing. Below are the details:
1) Tested with another computer, another USB cable, another HDMI cable. All have same problem. So this proves that it is
not the computer or cable problem.
2) Tested with coaxial cable + HDMI cable connected at the same time. This means I can switch to HDMI mode or coaxial mode when music is playing. So I do this:
- Listen HDMI, switch to listen coaxial. Both ok.
- Unplug and plug in USB.
- Listen HDMI, switch to listen coaxial. Both ok.
- Unplug and plug in USB.
- Listen HDMI, switch to listen coaxial. HDMI is muffled, but coaxial is ok.
- Unplug and plug in USB.
- Listen HDMI, switch to listen coaxial. HDMI is ok again, coaxial is still ok.
- Unplug and plug in USB.
- Listen HDMI, switch to listen coaxial. HDMI is muffled again, coaxial is still ok.
- Repeat few times.... HDMI sometimes ok, sometimes muffled. Coaxial is ok every time.
This proves there may be
something wrong with HDMI.
3) Then I tested with SU-1 again with HDMI. Unplug/plug in/unplug/plug in USB many times. All no problem. This proves that my
Audio-gd DAC HDMI input is ok. So this proves that there is
something wrong with the SU-6 HDMI output.