That seems to be a common problem and I'm not sure there's a simple answer. Many people report different levels of signal noise that seems to be introduced by the USB connection. In some cases it's present but not too annoying and in other cases it's unacceptable. Seems to depend on the amp, the X3 Tones (hi-gain?), the cables, the electrical outlets, etc, etc, etc. Best advice I can give is to experiment to see if you can minimize the noise. I think it's unlikely that you can remove it altogether, but likely others have more insight into this.

I have that problem in my setup with an XTLive and my laptop.  I found that by plugging everything into the same power strip and adding a ground wire from the Pod to the outlet strip reduced the noise substantially.

The other costlier solution is to get a fiber optic isolated USB.  They cost about $200 but it will definitely break the ground loop between the Pod and the laptop.

Data

I hooked up an Ebtech between the POD and mixer last night.  It didn't do away with the noise completely but it reduced it by a good 10db-12db.  It's definitely a ground loop issue!

Thanks for the "input",

Knobs

Just wanted to report that I am also experiencing the humming problem. I can experience it even without a computer attached, or anything else connected to a power supply. I have reduced the setup to the following:

- Connect a cable between the output of my M-Audio ProFire 610 and the guitar input (or aux input) of my X3

- The ProFire is not connected to anything else. No power cable, no firewire, no nothing. Not that it matters, but the power switch is also turned off.

- At this point there is no hum

- Touch the grounding of a firewire cable connected to the ProFire and the grounding of a USB cable connected to the X3. Now a clear, not very loud, but annoying enough, hum is heard.

Note that the only thing connected to a power outlet is the X3.

Disabling the input where the audio cable is attached (guitar/aux) removes the hum.

I'd be happy to find a solution to this humming problem (without spending a lot of money).

Message was edited by bjanders: Changed "this problem" to "the humming problem", so that is not confused with the other problems discussed in this thread.