I'm getting some sort of sympathetic vibration in a new DAW I'm building. Using Cubase (32bit currently) as I lower the buffer settings for the card, I can hear a buzz that increases in pitch at each step (and seems to get louder). Also, each plugin I load on a project makes the vibration louder, no matter what the buffer setting.

I think the vibration is actually coming from the power supply as I changed it out with another I had and that decreased the intensity.

The sound out (at least through the headphone jack) is not affected. What is affected are my powered KRK Rokit5G2 monitors. Even when not connected to that DAW they pick up the buzz! My KRKs have always been susceptible to computer-related interference, but never like this.

The new DAW is for an associate and we're hoping that his monitors will not be affected this way. I think we'll get another power supply, anyway, as the vibration is quite pronounced.

Anyone got a clue as to what's going on? Any suggestions for a power supply? Could this be some sort of "dirty power" problem?