Al,
You are correct about ground loops - usually ground and neutral are connected at the electrical panel. If you have different equipment plugged in to different locations and then chained together for audio purposes there is indeed a greater risk of a ground loop. Provided house wiring is correct then the major culprits are high impedance shields on interconnects, imbalanced RCA consumer gear and power supply leakage from components.
The digital issue is I believe related to the use of switched mode power supplies - which is common these days as they are cheap. These can create noise on AC power which can affect some equipment with less than perfectly designed power supplies. I have not seen any proof of this but my experience suggests that PC's are particularly nasty/noisy - they also vary in demand as a function of processor requirements - simply look at a Playstation - how hot it runs and the tiny size for all the current it takes....
As for RF/EMI - never been a problem for me - so I'd agree with Eldartford that this is a much rarer problem.
Here is a useful resource. Enjoy! BTW - it is great to see some well thought out posts on these subjects - I read your thoughtful posts with interest.
You are correct about ground loops - usually ground and neutral are connected at the electrical panel. If you have different equipment plugged in to different locations and then chained together for audio purposes there is indeed a greater risk of a ground loop. Provided house wiring is correct then the major culprits are high impedance shields on interconnects, imbalanced RCA consumer gear and power supply leakage from components.
The digital issue is I believe related to the use of switched mode power supplies - which is common these days as they are cheap. These can create noise on AC power which can affect some equipment with less than perfectly designed power supplies. I have not seen any proof of this but my experience suggests that PC's are particularly nasty/noisy - they also vary in demand as a function of processor requirements - simply look at a Playstation - how hot it runs and the tiny size for all the current it takes....
As for RF/EMI - never been a problem for me - so I'd agree with Eldartford that this is a much rarer problem.
Here is a useful resource. Enjoy! BTW - it is great to see some well thought out posts on these subjects - I read your thoughtful posts with interest.