There is a constant high pitched sounds coming from the plugable UD-3900 usb device. It makes this sound whether it’s plugged into a laptop or not (as long as it’s switched on), however the pitch changes when you unplug from the laptop.
We worked with Neil via our private ticketing system to resolve this issue.
For the benefit of others who may see this post when researching the above issue, a high-pitched noise from the adapter is not expected behavior. Please contact us at email@example.com if you are experiencing this issue, and we’ll be glad to help get things resolved.