XP10 and Creative X-Fi

Hi, I have 2 computers equipped X-Fi. One with X-Fi Elite Pro and the other with X-Fi platinum. Both AMD machine and they run on windows 7. Sine I both the XP10, last year I have been hearing some loud buzzing and noise sound, once the XP10 are plugged in the USB port. The noise does not go away by reducing any sound level on the XP10 or on the mixer. It sounded to me like a ground loop, but I plugged the XP10 to my other PC with X-Fi elite pro, but it was the same noise. When I plug them to my laptop, no noise is produced. Did anyone have the same problem and how can I fix it? The only thing is bothering me: no volume decrease, OS reinstallation (tried XP, Vista and 7) or reconnection helps with this problem, the only thing that helps is that I connect them to a laptop (running on battery or plugged in). All equipment is plugged in the same socket and no other equipment is connected. I have connected a numark X9 mixer, two CD player, two XP10, speakers and PC with X-Fi. If I don’t plug the XP10 to USB ports there is no noise (if this devices are only disabled in windows, noise is still produced). Can anybody help with this issue? Regards, Luka

I forgot to add, XP10 are connected to mixer. The mixer output is connected back to PC to X-fi auxiliary input and from X-fi output to speakers. If connected directly to speakers there is no noise. I need X-fi for recording audio. Does anyone have an idea, why the hissing noise is produced when connected so?

Seems like some kind of ground-loop problem, which comes from Your "loop" setup.
If You say that there is no buzz when connected directly to mixer and then to speakers, then Your setup is OK. But connecting everything in the loop can cause a lot of troubles, too much devices are involved. I would try to take a wire, which I would put into ground pin on outlet (where other devices are plugged in) and on other side try to "ground device by device".if it helps. If not try to simplify the setup to identify responsible device. Maybe use just one PC for playback & for recording. i don't think the problem is with EKS.

I have only one PC connected to the setup and I know EKS is not the probelm. I tried to connect ground from mixer to the PCs power supply (or metal PC case) and the noise was reduced, but not gone. It's better now. Thaks for the advice :)

Regards,
Luka

With highest probability You won't be able to remove the noise completly. The first issue is, that 2 EKS connected to mixer generate some noise because of signal going trough two paths, then another issue is the path back to PC, where some difference between potencials occure. Some noise I hear also on normal setup -> laptop+2EKS+mixer with direct output to headphones, with one EKS the problem does not appear. I think each path would have to be grounded to solve it somehow. Usually on setup with turntables You see it solved that turntables and mixer are grounded together into one point and this reduces noise to minimum.

You should try to ground EKS device directly to mixer if possible, it should help even more.

BR Pavol.