My system is powered by two P20s, each independently providing AC to the L and R channels. Out of curiosity, I swapped just one of the two AC power chords, first on the R channel (only), to hear whether the Sigma Sigma NR would trump the Audience Au24 SX. Inserting variables into just one channel is a wonderful way to make extremely revealing real-time comparisons using the presence of simultaneous hemispheric “bubbles” of music - the ear/brain is exquisitely sensitive to a variety of aural nuances, especially when presented with comparisons in a side-by-side manner.
As my speakers are powered by Class D amps, the Sigma NR were dedicated to them, to reduce the potential noise pollution going back to the P20. But then again, this could be only a myth as the inductive loads in AC cables behave like a low pass filter, making it nearly impossible for high freq to travel parasitically.