Hi
Have a problem with running an audio visual presentation from a laptop and projector into the PA. Running the laptop on battery is fine but as soon as the charger is connected there is a load of computer noise pouring in. I've had this problem with other laptops too. I tried changing phases and on one different mains phase it's quiet - on the other 2 noise appears which is an intriguing result. Any idea what's happening and how to resolve this if we only have one phase?
Cheers
GCT