On Sun, Nov 29, 2009 at 03:16:33PM +0000, Andrew C wrote: > Hey all, > > I'm just wondering, is the start of this short recording a ground hum > loop? It appears to be a weird high pitched whine in there as well... > > This was recorded on my yamaha psr e-403 keyboard going into my PC via > the Phones/Output on my keyboard.. I've ruled out the fact that it's > my PC/soundcard by trying it with an amp in a different room away from > my PC, but I still hear that annoying whine. > > Also plugging my headphones into the phones/output port on my keyboard > results in that annoying whine disappearing... > > http://moose.linux-coders.org/what3.mp3 Yes, that is a grounding problem with your computer. Laptop, I'd guess? It sounds like the same noise I was getting in mine when I first started using it. > > Could a DI box solve this problem? > It didn't solve mine. Neither did changing audio interface cards. The problem was/is that, inside the laptop itself, the mains ground is either tied directly to or inadequately coupled to the USB ground. What solved the problem was lifing the ground pin from the A/C mains adapter. Then the noise went away. I've been using that laptop, live, and in studio, for almost 3 years now. I just remove the ground pin from the A/C. -ken _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
