Really bad sounding power cables ?

Pangea & Signal power cords both seemed to dull the presentation in all 3 of my systems.

I have tried 3 different DIY PC compared to generic cord and noticed clear differences.
The cabling (old audio cables that were replaced by something better) was entirely different for each but the general differences were :
Solid core OFC copper (2x15AWG),
Very fine stranded OFC copper (10AWG)
And a mixutre of thin stranded UPOCC silver plated and plain copper wires (6X24AWG, roughly 16AWG).

Interestingly even with a headphone amp and its small power requirements the differences were audible.
They influenced the sound in a similar way as audio signal cables, and the thinner high purity silver plated cable proved thickness is not a substitute for quality even with power cables, giving a finer sound with a more delicate high-end.

However the thinner cable also seemed to be restricting dynamics and openess of the sound, possibly indicating the reverse... that quality is not a substitute for gauge, even with low power requirements of a headphone amp.
For the other thicker copper cables it was hard to say which was ’’best’’, better thought of as different ’’flavours’’.
That said I preferred the solid core the most, with a deep organic sound... but some of that smeared quality you get with some (or all?) solid core copper audio cables.

For the purposes of the comparisons to hear the differences in just the cabling as purely as possibly I bypassed the fuses and sockets at each end with only switches to select cables and turn power....
HIGHLY DANGEROUS if you are not trained in dealing with mains.

I hate that horrible sucking sound coming for my wallet when a big waste of money is lurking around. 

Shunyata Sidewinder Helix CX12 gets my vote. First off they are rigid as rebar. I have an old Hydra 2 at home on loan with three Sidewinders, one being the one you have to use to plug into the wall outlet as it has a 20A IEC socket which makes no sense. Anyway these cords are lifeless and the Supra distribution block I picked up destroys this older Hydra; or I don’t know as I have to use their damn cord to start with so not sure if the Hydra is decent or not. The Hydra with its cords sucked the life out of my digital gear... only used it for CDP/DAC and streamer.

Tried the the other two cords on their own and all my other cords are much better. No idea how old these Sidewinders are or what they cost new but not impressed with these. Can’t get over why they are so rigid. Closed in, cold sounding cords... you should try these - you’ll love em.

As far as shielded and unshielded it depends on the equipment. On digital I use Nordost Vishnu which does not have an active shield but by the geometry of the cable reduces EM/RFI. Built my own for my Bluesound Vault 2 due to the C7 connector and went with a shielded cable tied at the wall floating on the player. My WyWires and Kimbers are unshielded for analog components and feel they are more open sounding. Any cable with a twist or a braid is going reduce noise to some extent. Put an AC noise sniffer on a Kimber PC and you won’t believe how noisy this cable is but still a very nice cable so I give but maybe why I prefer other PC’s on digital.

Debate will go on and on if PC’s make a difference or not but I will say I took home a PS Audio P5 power plant and there is no guessing if this thing is working or not. I tried it with all my components plugged in and settled with everything but my amp; left the amp directly plugged into the wall. The difference between using the P5 was incredible. You want to try something that you don’t have to play games with yourself if it’s making a difference, let alone an improvement... drag home a PS Audio Power Plant. My Supra does a respectable job for the money and does not roll off or soften my digital front end but the difference with it in my system or not is not huge but it’s there; the PS Audio is just simply incredible. Maybe try one of these instead of PC’s.