I have two dedicated 20 amp circuits with 10g romex and PS Audio Power Ports ( SR Black duplexes coming soon) into my listening room but I'm currently only using one of the circuits.If using multiple dedicated lines, tie the grounds together at the distribution box or power distributor/conditioner.
I have 2 dedicated 20 amp line. Recently had IECs and OUTLETs on my Weizhi PRS-6s replaced with Furutech NCFs. As expected, the sound is more organic, lower noise floor ... very happy with the results.
Also suggested to me was to add a ground post to each Weizhi. The most remarkable improvement is tying the Weizhis together with a ground cable. It removed layers and layers of veil. Passages that were once congested and muffled are now crystal clear. Sound is more 3D, airy, tighter imaging, resolving, vivid ... I can crank up the volume several notches without any harshness.
All my audiophile level recordings always sound great but with compressed only music, Eagles, Springsteen, Santana, Heart ... they never sounded better and at higher volume level. If you told me all the harshness is mainly from noise, I wouldn't believe it.