Do power cords make a difference?

A little, about the same as tires on a car.

Different tires on a bike make a huge difference....

I just replaced the standard 18 gauge power cord on my neighbours speaker system for her iPad with a 14 gauge power cord from Home Depot - not even a high quality power cord

She is not an audiophile by any stretch of the imagination - but she heard the difference right off the bat - made her a believer.

Here's one explanation as to why they work...
http://www.image99.net/blog/files/category-you-need-good-power-cords.html

The amount of improvement you will hear depends on every other component and cable in your system - so don't be expect to replace just one power cable and achieve a significant improvement.

Also, not every power cable will have as dramatic effect on one component as it does on others.

E.g. for high current components I have found that 10 gauge power cables perform better than 14 gauge - but putting a 10 gauge cable on a source component may be overkill - so think about it's intended application

If you are into DIY then making your own is definitely a more cost effective solution and you can then ensure the connectors used are of good quality also

Hope this helps

If the car is a Yugo it's difficult to tell the difference...if it's a Porsche..it's easy...Better system..better improvement...

Calloway - actually it's the other way around - think of the upgrade as replacing the engine
- put a porsche engine in a Yugo - WOW
- put a posche engine in a porsche - so what
- put a Ferrari engine in a porsche . Better, but it's more subtle

Better quality components tend to have large power supplies that can handle the transient peak demands of the audio signal, so they operate at their optimum level

More modest components have smaller power supplies which actually restrict their performance. Having a quality power cord allows the circuit to handle the transient peaks, as a result they operate to a higher level of performance.

This does not mean good gear does not need a good power cable, but the better quality components actually need a much better quality power cable for a difference to be as discernible as more modest components

From my post above - a simple heavy gauge power cord from home depot was enough to elevate the performance of a boom-box

That same Home Depot cord on my Naim would not provide much improvement over the stock cord - but my Furutech is a whole other story. However, the furutech would not produce significantly better performance in the boom-box than the Home Depot cord did..

The most important and difficult aspect of power cord upgrades it to get the right match - i.e. best bang for the buck

To do this you have to either try several different brands/models or rely on the feedback of Agon members OR buddy up to your local supplier to get your hands on some loners.