going crazy trying to sort this out, just got a new windows 10 pc build from someone. been using a scarlett 18i8 with a mac for a long time which worked fine. whenever I plug it in to the pc I get erratic crackling. its not super loud, just irritating. I can deal with minor hum because its constant but the crackling is driving me mad. I tried other USB ports, different wires, I tried plugging the interface wall plug into a separate jack, changing sample rates and buffers etc, installing drivers.
eventually I realised it happens when I plug the usb in even when the interface is off. it gets worse when I turn it on, but its there whenever its plugged in. not sure what to try as I already plugged the power into a separate wall socket