Importance of power cable for Turntable?

I tried high end power cord on my vpi sds....absolutely no difference

With all due respect to previous posters, I would not mess around with a power cord. I suggest the best TT power supply that you can afford. Comes with a cord. Nottingham's Wave Mechanic is very good, Walker is said to be good (for AC synchronous motors). For DC motors, perhaps Origin Live or ???.

It's good to isolate the phono stage from the TT motor, unless you get a regenerating TT power supply. One way is to drive the motor from the other leg of the 220VAC. Recall that power from the pole is 220VAC. That is split at your breaker box into 2 x 110VAC - two legs. Get an adjacent pair, use one for phono, one for motor.

Alternatively, you can use power supply filters and isolation transformers,

I built my own controller after buying a Wave Mechanic. It's based on a precision telescope controller out of Art of Electronics. Improvement was significant - should have been, considering the parts cost more than the assembled WM. (air bearing TT, ESL's).

Folkfreak, Besides the facts that you want a lot of current carrying capacity (which equates to using thick low gauge wire), particularly for a power amplifier but maybe not so much for a turntable, since tt motors seldom draw more than 20W, and that in some environments, shielding is a good idea, define a "good power cord".  Does that mean "expensive"?  I guess I am trying to say that it boils down to low impedance, heavy gauge, and +/-shielding.  What else does a PC do?

@lewm Believing in differences in power cords, and being open to hearing them, presupposes that you value many more parameters in a cord design than current carrying capacity. Choice of materials (copper vs silver for example), geometry, resistance to vibration, damping, grounding and shielding solutions (such as active shields) - all of these influence and affect power cord performance and the effect can easily be appreciated on a table supply. And the cable doesn’t need to be expensive, choosing the right cable design is the key,

For instance the best cable for a table may not be the best cable for a pre amp say. For example I find Marigo power cords work really well on the table PSU but on my pre amp the same cord seems thin and forced. The ideal cable profile for a table is one that is lean and fast it seems.

and @bdp24 while the thoughts about my system are welcome (you must come round and hear it now, it’s a world away from what you heard last year) the same impact was clear on my friends system which is much much less expensive and complex

I would agree that geometryseems to have an effect, and “grounding” of course.