... abit confused: how does a power cord affect the presentation of sound...

Hello “insearchofprat,” I hope you are not overwhelmed with opinions as opposed to facts. Do you remember the little pocket FM radios that fed earphones. Athletic folks used them to exercise to music. Those radios did NOT have hard, collapsible antennas. How did they get the signals from the radio stations? They used the ground wire to the earphones as an antenna. It was a cute trick. Using a part called an RF choke, it is possible to isolate a wire, even a ground wire, at radio frequencies so that it behaves as an independent wire and can be used as an antenna. So we know that a wire can simultaneously carry radio and audio information. Have you ever been peacefully listening to music when the garage door went up, a refrigerator came on, or somebody turned on a hair dryer and a noise of some kind came out of your loudspeakers? Electrical garbage on the power lines can carry all kinds of unwanted “noise” into your audio gear. Ever hear police calls” on a PA system?

 For many years, power supplies were considered “necessary evils” in audio gear. They filtered out the power line frequency so gear didn’t hum and that was that. Nowadays, the power supplies are often more complicated than the audio circuits. There is a reason! You have heard claims of “blacker blacks” when fancy power cords are used. You have heard of intermodulation distortion. Suppose some electrical garbage on the power line gets into your amp; it’s way above the audio frequencies. Your power supply doesn’t stop it. It mixes with your audio signal, produces sum, difference, product, and quotient signals which themselves interact with the audio and buzz, hiss, rumble, and grumble their way into you loudspeakers. Oops!

 Enter the well designed fancy power cord. It is shielded and its conductors are made of fancy stuff and wound, twisted, and spaced in mysterious ways to reduce the amount of electrical garbage that makes it into you audio gear. This will be very noticeable on older equipment with simple power circuits. It may NOT be noticeable on new gear with exotic, well designed, power supplies. So the guys (or ladies) with the latest, fancy, hi-end gear say, “These products are snake oil. I have extremely fine gear and have never heard any improvement made by these expensive power cords.” But the fellows (or ladies) with vintage gear, stripped down “just the essentials” perfectionist products, perhaps budget gear say, “Wow, my whole system improved when I installed the Big Bad Bear Power Chord (or power conditioner, or magic noise killer). My top end became much clearer, the mid range sweeter, and the blacks blacker!” Both are correct, but should not pass judgement on the results that others experience. Some of my gear shows a difference and some shows no difference at all. A fancy power cord? Use it where if it works. If it doesn’t, send it back. Keep Smiling. I hope this helps.