For some reason I can actually hear the multi-track USB 3.0 port recording when I use the USB flash drive (Sandisk Extreme 16.0). I did not have this problem when I first got the USB flash drive. It’s like I hear it counting beats within the speakers and I don’t know why. Has anyone else had this problem or know what to do? Thanks.
It’s possible that you have ST3 fader up. It’s known that ST3 (Stereo input 3) can introduce the noise you are describing if there is nothing connected to it. Try muting the ST3 input.
ST3 is unbalanced and the port is adjacent to the USB port. With something plugged in it’s normally sufficiently shielded, but when open it can pick up interference from the USB port doing transfers.
Muting ST3, or using it, should stop the effect.
The audio might be visible in the metering if this is the cause.