A Better Bluesound AC Cable?

I don't understand what you're saying. Is it that you dont believe aftermarket cables make a difference over the cheap stock cable made of who knows what materials? Or do you mean with the Bluesound Node's low current draw and no separate ground there would be no audible difference?

Thanks @jarcher .
I looked up Wireworld PC's and they're all about lowering the noise floor, which is a good thing.

This C7 has silver coated copper and is a decent price...
https://soundapproach.com/wireworld-mini-aurora-map-mini-power-conditioning-cord.html

Here is a Cullen C7...
http://www.cullencable.com/c7-power-cable/

Can anybody explain why use a PC which only has a 2-prong plug?

Wouldn't a figure 8 (C7) IEC to 3 prong plug have an advantage over the 2 prong type? 
Noise would be drained via neutral and ground conductors to the 3rd pin on the plug (a proper ground).

Shunyata makes what looks like a high quality adapter.

https://shunyata.com/products/accessories/venom-v14-c5-c7-c7p-mini-power-adapters/

There’s an Isotek C7 cable for a decent price, although I’m not familiar with their PC’s.
I do believe that a cable using isolated neutral and ground conductors tied to an earth ground (3-pin connector) would be the preferred design for draining noise vs. a 2- pin design.

https://www.upscaleaudio.com/products/isotek-evo3-premier-power-cable

I think the Shunyata Venom would be a good choice, but it's another cable without an earth ground.

Well, I tried the Wireworld Mini Aurora C7 on my Node 2i ($120) and the improvement in SQ was dramatic. Dynamic, spacious, detailed yet realistic. I recommend it if you like a forward presentation; I do not.
   In my system, the soundstage was pulled forward to the front of the speakers which caused me to  lean back into my listening chair. The drummer in a jazz combo was almost seated in my room instead of way back near the wall. Very realistic and would sound terrific if my room extended back about 8 feet.

So, still looking for a C7 cable; one that is more relaxed. But this exercise proves to me that using an aftermarket PC on the Bluesound is a worthwhile upgrade. 

@grdrbob, IME Audioquest PC's don't provide a black background like other cables.

Bob, in your case the quality of the C7 you chose was not enough to make an impact. In my case, the Wireworld was a transformative upgrade; it was so superior to the stock cable.
The AQ C7 by all accounts is not a very good cable, also the higher end AQ has been discontinued.
Many of these low current 15 gauge C7’s do not equal the performance of a manufacturer’s full line of power cords.

I doubt that your system is limiting. Mine is pretty revealing with Silent Source and Siltech ICs, Audience PC’s. I hear the differences in each cable I swap. I can hear a good from bad C7 when used on the Bluesound.
I think you should try a different cable.

@gdnrbob, 
I have the Wireworld Mini Aurora C7 for a 30 day audition, $120 for 5 ft. Read my comments above as to why I'm returning it, but it sounds terrific. Realistic, lively, transparent. It really opened up the Bluesound.

Bob, I never tried the internal DAC only because I have a very fine Audio Note plus a High Fidelity S/PDIF cable. 
Sounds wonderful with the Wireworld PC, but pretty dull and uninvolving with the stock.