Yeah with my Pangea power cables I noticed more bass on my power amp but little difference on my pre amp or my power conditioner.
Now adding the power conditioner and replacing the wall warts with linear on my table and phono did make a significant difference in terms of the overall noise floor of my system. Which was most effective or if they all had an effect is unknown as I did them all at once.
On RCAs I had been rocking the cheapest QED ones which were grand. Upgrading to the Van Den Hul’s made a difference, but a €120 a cable x4 difference? Not so sure, with the exception of the cable from my phono to my preamp which is now a balanced XLR which was well worth the change from the unbalanced RCA.