Problem with New System - Diagnosis Sought.

Just put together a new system from here and Craigslist. Consists of my long-time owned NAD T550 DVD player/Krell KAV-250p preamp/Krell KSA-250amp/B&W 801 series3 speakers.
Problem: Noticable in choral/vocal works in high register around just one frequency coincident with the singing, there is a chirping sound. Like crickets on a summers night or a high pulsating whistle.
Sounded to me like a loose tweeter vibrating, but sound comes from both tweeter and mid-range driver and from BOTH channels. It's there at low volume as well as high.
The first thing I would do is try a different pair of speakers that are known good. Assuming there is no damaged equipment, the problem is with the speakers. I've worked with several pairs and have owned the 802 S3's. They have the same setup for the mids and highs that your 801's have. The high frequencies on those speakers are extremely difficult to live with. I tried just about everything you can think of to get good sound and had little, to no success. One thing you can try is to go over all the screws on the cabinet and make sure they are all tight. They loosen up over time. Also look at the tweeter grill very carefully. Some people remove the grill (you're not supposed to). Make sure its secure.
Sounds like you got beat!!
Sounds like something is wrong somewhere. I would first try a diiferent pair of speakers. If the problem does not go away, there is something wrong w/ the speakers. The 801s should not exhibit that anamoly. The only reason the high freq on the 801 would be hard to live w/ is because they are revealing of any weaknesses upstream, they reveal what's there.
Sorry guys - the bad sounds are on the recording!!!! Try this for yourselves.

The Robert Shaw Handel's Messiah, Track #2, "Comfort Me", at 40sec mark and other high sustained tenor notes. I've had this recording neigh on 20 years and never heard theses bad sounds before. I would be most interested if any of you have this recording to know what you hear here.

Sorry for a bad post.
It's not a bad post. You fixed your problem. You're not the first one to become the victim of a bad recording.
I wish I could attach a drawing to show how I'm now setup. The speakers are back square to wall about a foot out. The mid/top swivel units are facing to about 3 feet either side of me with me not central, but to the side in an alcove where the walls are angeled to the speakers and where there is a little open space behind me. The balance is of course adjusted to compensate for me being off center and sound is very detailed and clear with inproved focus.