Furutech has always had a "lightening" effect in the music, something my old mentor, HP, noted in one of his reviews when he was comparing Furutech to Nordost back in some issue in 2010 or 2011. He found the same thing. And he was well aware of power supply issues. And he and I found the same thing. So, transparency sometimes comes at the cost not of an imbalance elsewhere in the system, but because of a leanness in the component (fuses included). Nordost had this very problem until their second generation (meaning, 2nd generation Frey, Try, and Valhalla, and I had ALL of them), wherein they improved in the lower midrange and upper bass. It's not always a matter of 'balancing' the system: sometimes it comes from not recognizing (until years later) that a component had something - not so serious as a 'flaw' but just, perhaps, a 'subtractive' or 'additive' quality so slight, it was easy to miss. I've tried the Furutechs in every component in my system and, based on the fact that they released the NCF line outlets a few years after the GTX-D line, they, too, realized what was missing, because it is EASY to hear the difference between the two (again, I had both, and if you read prior posts, you'll see I sold my Rhodium to someone who posted on this thread). Quite a few posters on the 'Whats Best' forum came to the exact same conclusion, and their equipment was FAR superior to mine (although I don't know that their ears are).
This is why HP used the Gold instead of the Rhodium: a certain kind of "accuracy" at the expense of both sweetness and musicality. I don't make statements until I've thoroughly tested something repeatedly. And having had Hi Fi Supremes, Synergistic originals, then Reds, then Black fuses, along with AMR and Audio Horizons, and placed them in ALL my setups, there might be the slightest chance I'm wrong.
But as strongly as YOU feel it can be explained by technical issues in power supplies, I feel that if something consistently demonstrates the same issue through 5 different manufacturer's lines of product, and 3 different setups, it is unlikely I need to be an electrical engineer to trust my deductions. It is best for people to be aware of BOTH of our assessments. Think of us as filling in for the now discontinued, and fabulous, inter-commentary system that TAS used to have. Now we, the consumers have to do the work that they once did for us thru that system of different reviewers with completely different systems commenting on a component. Only now, the components are of the more microscopic variety: 1" long, and 1 ounce, instead of 24" long and 50 pounds. It's what we used to call 'getting down to the real nitty gritty.' Now it's capacitors, fuses and internal wiring. Will it never end???