I dug my old Behringer UCA202 out of my shed and plugged it into a computer. I did some tests and it appears to be working fine... apart from some noise signals on the line input channels. I'm not sure where this type of noise could be coming from; weather it's the computer, the powered USB lead, or the device itself. What components could cause this type of interference?
I have unplugged everything else from the computer (except power lead and VGA monitor).
I have tried plugging the device into a powered hub. The DC input on the hub states 5v 2.5A, but I'm using a 5v 2.0A power source. I don't know if this matters.
This is the recording:
Only the monitor, mains lead and UCA202 are plugged into computer, and I unplugged the monitor from the mains while recording. There is nothing plugged into the UCA202.