Power cords - a BASIC question

Systems with digital components are more sensitive to power cables than purely analog systems. Digital components are notorious RF producers and can easily pollute the rest of a system. The filtering in power cords is probably doing more grunge suppression on the ground from the digital component than on the incoming electric power.

In order for a line cord to alter the signal that passes thru it, it would need to have in it the things that are used to alter signals. That is, it would need a filter network of some kind. Filter networds generally consist of capacitors, resistors and inductors. Line cords are made of wire and insulating material only. Also, keep in mind that the internal circuitry of your equipement does not use electricity in the form that it is delivered from the wall to the equipment's power supply. The power supply brutally hacks up the incoming sinewave and reconstitutes it, so to speak, before it is use by the internal circuity. The process itself that the power supply uses to ready the electricity for use is generally far more trouble (RFI) than junk that may be on the house wiring.

Your point about the wiring in the wall is valid. Electricity moves around in a lockstep fasion. If there were such a thing as a good wire and a bad wire and you put these wires in series (a line cord is in series with the household wiring), whatever was happening in the bad wire would also be happening in the good wire.

If you imagine electricity as water in pipes, the pipes have to be full. So, when pipes are hooked together water that moves in one has to moved exactly the same in the other.

Steven: If this were so, then why do various line cords, that do not have any of these features, sound different from one another? I think that you must have left something out. Oh well, back to the drawing board.

The medium that signals pass through must affect that signal, therefore differences in medium = differences in sound and therfore no filtering device is needed to affect sound. I have also had experience where the same brand power cord at one meter and two meter lengths sounded different. I wrote the designer who agreed, and recommended the longer length.