Noise from plugging in USB?

[fractalsaurus]

I've been getting this weird high pitch noise no matter which USB cable I plug into the PBC from my mac laptop. Is this normal or has anyone else experienced this?

 

[rjmmusic]

That's probably a grounding issue. Here's how I solved noise issues:

http://www.rjmmusic.com/forum/index.php?threads/usb-noise-and-isolation.2085/