I have an O2/ODAC connected to my work laptop. It exhibits noise whenever it is connected via USB (it also has an analog input that has no noise). If I power down the laptop the noise goes away (this amp is normally dead quiet). I have tried connecting it to the laptop's USB port and the dock's USB port, but that makes no difference. I have also tried different cables (Mini-B) with no joy.
What are my options for dealing with this? I know that USB isolators and fancy cables exist, but are there any DIY solutions to try before I get out my wallet?