Why the Hell...

[tw]

Originally Posted by Elspode

Mostly, I just want it to go away without time consuming experiments, ...

The experiments are neither time consuming nor too complex. For example, simply put that 'three prong to two prong' adapter on each power cord, power on, and learn what happens. Posting that last reply took longer.

Paying in Radio Shack for that adaptor or the isolator is too much money. The adaptor on computer and test. The adaptor on power amp and test. Adpator on power strip with both units powered from that power strip ... and test. Move system to another building and test. Only then can any reply here post something useful.

The concept is quite simple. Every wire inside every cable is a possible 'hum' conductor. For hum to occur, one wire must carry hum current in and another carry hum current out. If any one wire is found to be a 'hum' carrier, then half of the problem is known so a reply can suggest a solution, or a reduced number of suspects exist.

Suggested was the easiest and fastest way to solve these type problems. The fact that you don't know what is being targeted suggest you do not yet know how quickly this can be done and that learning occurs only after performing these simple experiments.

Assumed is 'boxes' are powered by three prong connectors - correct? Also assumed was power strip is only a power strip - not a surge protector.