Is the sound at a consistent volume over MOST of the preamp's volume range? If so the sound is most likely emanating from the preamp. If this sound is very low in level or you have really efficient speakers this could be completely normal. Also most receivers pull a trick where if there is no signal coming IN they completely mute the output so you don't hear this low level background noise. The problem of course is that this muting threshold can remove tiny inner detail too which is why high-end products don't us it. Please provide more information on the specifics of your equipment.

How close to the speakers are we talking about? Have you talked to your dealer about it? You might want to stop into the show room to see if his demos do the same.

You first have to identify whether you are hearing a "buzz" or a "hum" which are both low frequency in content and normally related to a grounding/isloation problem or whether you are hearing some other sort of noise. A ground loop will typically produce a "hum" which is 60Hz noise.

Lower the volume on your pre amp and disconnect one of your interconnects at the CD player end. Raise the volume slightly and touch the center pin of the RCA on the interconnect you have just disconnected. The noise you hear is a 60Hz signal. If the noise you are hearing through your speakers isn't 60Hz, then you have a different problem then a straight ground loop.

"Buzzes" often come from interconnects not dressed properly or other situations not related to the equipment per se.

"White noise" is what you hear in between FM radio staions when the mute switch is defeated. It is broad spectrum noise that has considerably more high frequency content than either a "hum" or a "buzz".

Once you determine what sort of noise is present and at what distance it is audible, we might be able to provide more assistance.

I would start by investigating a ground loop. If there's 60Hz anywhere in what you are hearing it is ground plane related. Phase distortions within your speakers or room might lead to an "open" sound with either a buzz or hum.

Start by placing something like, "tracking down ground loops" in a search engine and read about where the problem is most likely to originate. With separates the most common cause is improper AC wiring and/or components sitting at different ground potentials relative to AC ground. You can begin to trace the problem by unplugging (AC and interconnects) all components other than your power amplifier and listening for the noise. Add back one component at a time until the noise appears. At that point you've found the originator, now you just have to solve the problem. Go down to the hardware store and spend a few bucks on an outlet tester. You need to know the outlets are wired correctly before you do much else.

Is the stereo connected to any video sources? If so try disconnecting the video source from the preamp and see if the sound goes away.