Naturally this topic inspires polar opposite opinions. I have approached the problem by assuming power cables *probably* make a difference but I don’t have a lifetime to prove it one way or the other, nor do I have the deep pockets necessary either. But I wanted to do something because my power was particularly noisy. So I decided to compromise. I looked for reasonably priced power cables that are very well made. I tried Anticables but found them too stiff. I wanted to buy Shunyata but I didn’t want to spend that much. I turned to Iconoclast, available through Blue Jeans Cables. They are beautifully made, very flexible, and most unusually, I could buy the exact length I needed to the inch. This kept each cable off the floor and not touching any other power cable.. They sounded fine, which met my criteria of reasonably priced and ax. “good enough”. in SQ
On the issue of installing a dedicated line, I’d advise against it. I had an electrician lay out a temporary dedicated line running from my panel into my living room and we found it just as noisy as all the other circuits in the house. The electrician also tested the line coming directly into the panel and it was equally noisy, clearly indicating that installing a dedicated line would just cost me money I could spend more productively elsewhere. I bought two Tripp-Lite Isolation Transformers instead, one for my digital components, one for my analog components, and they reduced noise to almost zero.