What do I do if I have a buzz or hum in the output of the 460 Presentation Audio Mixer?
1. Check input connector wiring. 2. Check output connector wiring. 3. If the hum or buzz is present in inputs 3 or 4, try connecting the chassis of the source equipment to the chassis of the 460. 4. Check for a ground loop problem. Inspect related systems equipment grounding to see that all system components are on the same AC ground.