I get exactly what you’re hearing and you summed it up nicely. The Accuphase doesn’t just control the speakers, it disciplines them, IME. That taut, truthful bass, once you hear that kind of finesse and layering, the “ultra-wide” soundstage is easily discernible.
As far as power cords, I highly recommend 聖HIJIRI SM2R-L "SOUND MATTER" Power Cord. For context, I am using a full of 聖HIJIRI cables in my system. The SM2R-L will get you very close to flagship “TAKUMI” Maestro Power Cord at lower cost. These cords pairs beautifully with Accuphase, like two-peas-in-a-pod kind of synergy.

