My good friend that is in the business and very very knowledgeable
calmed that a well made 10ga power cable reduced his soundstage... I'm
not saying it will or won't but why would it? I would like to know the
science behind this. I did research on here but not satisfied.
Its all about voltage drop. But first:
I want to understand the actual physical properties the 4 feet from the wall to the amp that make all these audible changes.
The in-wall wiring has very good performance on account of being solid core. But solid core is not legal for power cords.
Now about the voltage drop- depending on the amp a voltage drop occurs across the power cord. I've seen on the bench a 2 volt drop across the power cord rob a 140 watt amplifier of about 40 watts- obviously this can be significant. In addition to the voltage drop there is a high frequency component. This is due to the fact that power supplies are composed of a power transformer, rectifiers and filter capacitors. The rectifiers can only turn on if the filter capacitors are at a voltage less than that of the power transformer. At this time current charges the filter caps and then the rectifiers shut off. This might be only a few milliseconds with a high slew rate and so is a high frequency event. If the power cord lacks the bandwidth to allow the current to flow unchecked, the result is the power supply won't be properly charged.
This has a measurable effect on amplifiers. In case anyone has any doubts, it is easier to test the effect on the amp rather than measuring the power cord itself. The output power, distortion and output impedance are the things to be measured. You will find that power cords most definitely have an effect on these things!
If your power cord is warming up, or is getting hot at either end, its a good bet you have a problem. You may not think this can affect audible things like the soundstage, but if power is restricted, distortion and output impedance are higher, it will affect not only that but other things like tonality and detail as well.
So bottom line: this is a measurable phenomena as well as audible. The audibility relates directly to the measurable changes caused by the power cord.
