I don’t understand it, but in my experience, clearly the biggest impact came from improving the power cord. Interconnects and speaker cables provided nuances, but power cords lifted veils, as they say. Not just replacing the stock cord, but moving up the food chain, in my case from nordost shiva to Vishnu to heimdall II. Sources improved more than my bel canto mono blocks, but all power cord improvements better than any other cable upgrades. Can’t explain it.