I have a ZED10FX mixer that I use for Zoom calls with a guitar, a mic and a backing track. I use the USB out from the ZED to the computer, and choose that USB input as the "microphone" in Zoom. The problem I've been having is that (only) when the ZED gets connected from the USB to a computer, there's a high pitch noise or hiss that comes out through the mains, the aux and the headphone out of the mixer.

To troubleshoot, I've tried different USB cables, and even a different computer (one Windows 10, and one windows 7) and the noise remains. I also tried different USB ports, and even a powered USB hub on one of the machines. Cannot figure out how to get rid of the high pitch noise. You can hear it in the attached files.

The Windows 10 machine is the main one, the one I use for Zoom. I use the Windows 7 laptop to play band in a box tracks into the mixer. When I was troubleshooting, when I connect the USB to the laptop, the noise gets louder as the volume on the mixer is increased. However, when the USB is connected to the Windows 10 machine, the noise is present with the volume all the way down, and it doesn't get louder when you turn the volume up.

The other thing I notice is that when I change the sample rate and bit depth setting in the windows device settings area (screenshot attached), the noise changes, some settings are louder than others.

I started doing some searches and came across others who experience the same issue as me with the USB. My volume in the windows recording devices settings for the mixer doesn't have any effect on the noise as a few mentioned in the following threads. Now I'm really at a loss as to what the cause could be, but it doesn't seem to be isolated to my unit.

• Is this the case with all these mixers? Maybe it's time to move onto another mixer altogether?

  Update:
  I have just discovered that the noise is not transmitted into the computer via the USB. Did a test recording with the USB as the source and there is no noise whatsoever. So it seems while we can hear it coming out the speakers, headphones, etc., the person on the other end of the Zoom call will not be hearing it. Nevertheless, it's still annoying and I'd like to be rid of it if possible..