For me the biggest impact was with my cd player a modded sony scd-1. The cable provided a blacker background that was immediately noticeable. The upgraded power cables on my other components had no impact.
Thank you for your feedback to date -- just always heard about when updating cables -- work from source components out. However, never quite understood if you have an Integrated Amp -- should this be first or the source components CDP, DAC, etc.
Again -- I will take advice and move my first power cable around a bit and listen. Just may be a bit of time before second power cable arrives.
Experiment for yourself is the best advice. I know many will say source first, this wasn't so in my case. Your room, your gear, your setup and your ears are different. That's why they make so many different flavors.
BTW, if your components are plugged into a power conditioner, you may find that a cord on the power conditioner is the best place to start.