@audiodwebe Few years ago I had RS Dmitri with its https://sigsound.com/running-springs-audio-mongoose/ 20A power cord and I have also tried its other, more expensive https://sigsound.com/running-springs-audio-crown-jewel/ power cord that my friend had with its RS (Jaco?) conditioner. The moongoose power cord is in fact Cardas Golden Reference cord and at the time I remember reading that internal wiring in RS is all from Cardas copper.
The reason I am writing this is because manufacturers have their house sound, not only with Ic and speaker cables, but with their power cables as well (at least few that I have tried extensively, like Cardas, Nordost, Shunyata and many others) and that ’first’ cable going from wall to conditioner will have a major influence on the ’flavour’ of your system.
The 'size' or the thickness does not mean a thing (in this case) At the present, I am using AN Kondo power cord in my tube preamp that has the smallest diameter of all I have tried, but it gives me the sensation of the deepest stage, like no other has.
Do not know what other power cables and gear you have, but the cable that previous owner had with RS might be great with his system, but you need to understand is it best for yours too.
There are some gear brands that are known for ’liking’ certain cable brands, in broad sense,like Spectral and Mit, Ayre and Cardas, or Burmester and Nordost, and so on, but there is not an clear advise that anybody could give you, which cables to use, since there are many factors (choice and combinations of gear you have and your individual taste)
I believe that power cords, or even better, the combination of your gear and their power cords have a major impact on the type of the sound you will end up with and in my case, choosing ones that are ’best’ is something that takes time and patience...and best advice I can give you is to try any one you can get to understand their ’flavour’...and than pick the ones you like best...
Not to add more to possible confusion, but sometimes the single ’best’ one is not the ’best’ one in grand scheme of things....its like cooking....sometimes some ’great’ flavour could become too dominant...but, that is a ’next level’ story...