audiphile power cords

Do upgraded power cords really make a significant difference in sound quality? I have a Jolida 502p that I think sounds pretty good. What do you recommend for a power cord that would make a significant improvement?
Rodman - thanks for the tip! That will be easy to do.
Here are a few questions directed mainly at Ralph “Atmasphere” regarding his post.
First Ralph I have great respect for you and your contributions to these forums, your advice has been very helpful in allowing me to push my system to new heights.
I will start with a crude question. If a simple power cords can improve the quality of sound to the extent that it warrants its exorbitant price tag, why would you not (as a designer and seller of amplifiers) sell your amplifier straight out of the box with such a power cord. From a business perspective you could be providing your clients with more value and pocketing the added margins that others in the industry are essentially taking from you. From the client perspective I would feel pretty bad about a product that I paid top dollar for and that at a later point I find out that it is not performing at the peak of its performance.
Clearly as manufacturer you want to hit a specific price point, but why are the cords then not offered as options at a minimum?
Now on to the more technical aspects, I read the link to the Shunyata article, it was a very interesting read. The charts in the article show some numbers and that is a great starting point, I applaud Shunyata for trying to show metrics for their products. Mr. Gabriel is claiming that the magnitude in difference that a cord will limit current between stock cords and his products is 40% or 50%. In real terms are the figures being quoted relevant, and how and why. For example on the graph of the Black Mamba vs the Venom the magnitude of the difference between the two graphs is only large between about 7 and 20 usecs, is this significant?
Comparing all the graphs, it seems that the factors that contribute most to rapid current delivery are gauge and surface of contact (i.e. better connector). It would appear that the difference between the Venom 3 and the 14awg Hubble is in the order of magnitude from what you would expect from a 12ga vs 14ga. Would you agree with this observation?
Regarding noise and improvements to the noise floor, if you want to filter out noise why not install a filter, why use a power cord as line filter?
Finally, when reading through this threads and the many others on this topic there appears to me to be a consensus that apply to all power cords regardless of price or brand, that is there is no way to predict with any degree of certainty whether a particular cord will improve the sound of a given system, the only way to know is to try. This puzzles me. That not every power cord can work in every situation, is something I can understand and would expect. But I cannot comprehend the fact that manufacturers generally don’t provide guide lines or target specific applications and even if they do those results do not appear to be repeatable. To me it seems that there is a lot of pseudo-science disguised with high tech graphs and instrumentation and very little testable and refutable theories out there.
There you are more fuel for the fire!

Sorry, but I have to disagree with this statement,
I used a double run of 10 AWG, which is the equivalent of 4 AWG
For equivalent wire gauge of a double run using same wire, you double the cross sectional area, not the diameter. Looking at this wire gauge chart, a double run of 10 AWG is equivalent to 7 AWG, and this AWG calculator confirms that.

Hope this helps with you future calculations.
I have a question, Does one reap better performance benefits with some of the state of the art power cords out there versus some of the state of the art tube rolling out there?, currious I am, what's your opinion out there?, In other words, which tweek gives a system the best up-grade?, I understand I will likly do both, just something I would like to know.