Importance of power cable for Turntable?

It makes absolutely no difference what so ever. Use whatever comes with the table and spend your money on something more important like a Pizza.

Hi,
TT power supply (especially if it is an outboard one) will most likely benefit from a better quality mains cable and material, so yes it sounds better in many ways.

Why only power cord, just do like this person. 

bdp24 reiterates and clarifies lewm:

It is not a symmetrical situation; if a difference between two competing components---in this instance power cords---is heard, the system is then ipso facto transparent enough to reveal that difference. On the other hand, if a difference in NOT heard, that does not necessarily prove a lack of transparency, for, as you imply, there may in actuality be no difference to be heard.

Close. Still begging the question though, and leaving out another explanation. If you can't hear it, it might not be the system at all. It might be you.

Why not? Isn't this something we've all gone through? I sure have! Back some 30 years ago I had been convinced by Julian Hirsch, et al, that there was no difference between wires, or even a lot of CD players for that matter. And when in fact I first went to listen and compare and see for myself I wasn't at first able to hear any difference.

At first.

But I kept at it and before long was not only hearing but able to describe and reliably evaluate differences between CDPs, transports, interconnects, power cables, speaker cables, cones, footers, capacitors, diodes, resistors, CDs with green pen vs CDs without, wires of all kinds, wires that had been cryo'd vs wires that had not, wires that were jumbled vs wires that were spaced and dressed, on and on and on. Not to mention speakers more than 1/16" out of alignment, whole systems demagnetized recently vs long ago, contacts recently cleaned vs long ago, and yes fuses and yes even which direction the freaking wire is going. Appliances turned on vs turned off. Breakers connected vs disconnected. Late night vs mid-day.

Are we there yet?

Not even. 

Speaker cables elevated above the floor on porcelain insulators called Cable Elevators. Speaker cables elevated above the floor by wood, plastic, paper, carbon fiber, other devices. Interconnects and power cords, ditto. CD player sitting on phone book. CDP sandwiched between phone books. CDP held in hands. CDP resting on Cones. CDP with cones in one place. VS another. Sitting on this. VS that.

There's four different methods I use before listening: warm-up the tube amp, play the XLO Test CD demagnetizing tracks, run the Radio Shack Bulk Tape Eraser over everything, and spray everything with Static Guard Anti-static spray. Why I do this and how often has nothing to do with anything anyone told me, nor was it determined by thinking, nor definitely not by typing on a keyboard connected to the interweb. How often I do this was determined by ME by LISTENING and COMPARING. I simply tried going different amounts of time between treatments, noting the difference, and deciding based on that how much deterioration I was willing to take as the price for the convenience of doing nothing.

So are we done beating this dead horse?

Not even! The corpse may be rotting but watch me beat the meat off the bones and the bones to dust!

In the beginning when I discovered BDR Cones they were so amazing I would take 3 with me to annoy and impress my friends. Richard had a dirt cheap one-box player with some hair-thin wire going to crap-box speakers. First we sat him on the sofa and moved the speakers to where he was surprised to find he could actually hear imaging. Then we put the Cones under the CD player. No problem whatsoever, he was amazed. Stupid Cones, $60, cost more than his whole stereo.

Another friend Doug, all through high school and college he was the only other guy I knew with any real interest in audio. So I brought the Cones down to show Doug. Who had such an enormous pile of mid-fi you could hardly believe it. I mean imagine a 1970's Pioneer integrated, and tuner, 1980's Sony Beta, Sanyo CDP, Comcast cable box, Playboy Channel decoder box, couple other no freaking clue what they are boxes, all stacked one on top of the other. Connected with patch cords. Connected to 1970's JBL speakers with lamp cord. 20 ft on one, 30 ft on the other. Probably 5 ft of it snarled around in the tangle of wires behind his pile of mid-fi crap.

It was the biggest challenge ever just figuring out where and how to get three Cones in there without bringing the whole mess crashing down.

When we did though, and I still can hardly believe this, but they did make a difference. Not much. But shocking, in those circumstances, to hear anything at all.

Not only me but others on this site have heard improvement moving just one wire just a few inches.  But whatever. There is still the slight possibility that something someone somewhere can dream up is different yet sounds exactly the same. There might even be some system somewhere so incomprehensibly unimaginably seemingly impossibly opaquely muffled and congealed and untransparent that everything comes out the same.

But for the most part, it seems pretty darn clear to me anyway, if you can't hear any difference at all its not the system, or any part of it, or anything even remotely having to do with it.

Its not the system. Its there. If you can't hear it, well there really is only the one thing left that it could be.....