Hi Craig, that's an interesting suggestion. I can see why it should work as long as there is some other way for the USB ground reference to exist in the Stomp and the host PC. I assume this must be existing via the audio interfaces and whatever the alternative ground connections are that are causing the loop in the first place. I guess my only concern would be if a large differential voltage could build up between the computer and the stomp and maybe damage the USB interface should this alternative grounding be removed, perhaps by accident if the setup is changed. However, it obviously works for you, so thanks for the idea. FWIW, I did a bit of fiddling about at the weekend and identified the issue with my set up as being due to my external monitor (it has an HDMI and USB interface). Just touching the tip of either plug to the metal of the connector housing on the laptop triggered the ground loop noise. i.e. connecting either of those to the laptop when the stomp is also connected caused the ground loop, without both all is good. When I first tried it I removed one plug and then the other so missed the fact that the monitor with its built in usb hub is a common source.
I think monitors being the cause has been reported by others. The issue for me is use this monitor for everything, but at least I know i can get a fully functional rig until I maybe try your trick or whatever to isolate the stomp.
Once again, thanks for your help.
regards
S
