I have been getting an annoying hum in my Mackie monitors recently, and after much trial and error, found that it seems to be caused by my 19" Apple Flat Panel Display.

The instant the monitor goes to sleep the buzzing dis-appears. Re-appears when it comes back on.

Any idea why this is happening?

Dual G4 1.25, 2 Gig, 002r .OSX 10.4.2 - PT 7
Vision Daw 3.6, RAID O, RME 9652, Kontakt 2
Yamaha 01V/96 - Waves Plat - Reason 3 - RMX