Reply to Loud audio pop which appear to be cause by voltage surge passing thru USB cable.

I'm having the following problem with my "Sony VAIO" laptop and any of my USB audio devices (Kontrol S4 and DJM-850 mixer): I'm getting a loud Pop intermittently out of my speakers when I'm using my dj software. As of right now I tested by using another Sony VAIO laptop which I have around and it did not produce the same problem when I run the DJ software which let me to believe it is an issue on my original laptop. I tested also by only using the laptop on battery power and I still get the same problem but the sound is a bit less loud. When using the DJM-850 mixer the pop sound more like a "Beeping" sound that still occur intermittently. For some reason the issue is worse when the PA-speaker is connected to the same power outlet as the laptop. Have any one experience this problem and what was the fix? I contacted Sony and would be sending the laptop in for repair at a cost.