Why Expensive power Cables when Romex behind Wall?

Guys, if installing a supposedly high-quality power cord is actually producing audible differences in your system, then the power cord is not just passing the power without further distortion -- it's changing something. If your electric power supply is so bad that it needs to be filtered, then a power cord is NOT the way to achieve that objective -- you need a power regeneration system, such as those made by Richard Gray, PS Audio, Monster, etc. After you get the regenerator, THEN go for the good quality power cord.

(For the record, I also have high-quality power cords installed on most of my gear. These cords are probably the only "tweak" I've acquired that provided very little -- if any -- improvement in my system.)

Sdcampbell... Now that you are accustomed to your system's sound; ALL AT ONCE without listening; replace all of your cords with the typical black 18awg cords that come with most gear and computers. Then play your favorite most listened to recording. Does it really sound the same?? If you replaced the cords over a long period one at a time, you may not have noticed any change, since it was gradual.

Sdcampbell, being an Audiogon member that has always read your posts during the last two years ( I began in 1999), I am surprised by your comments.

You built your system with quality audiophile gear and yet you report that power cords provide very little if any improvement in your system.

This completely baffles me, as my results are so opposite from yours. You may have read about the extremes I have gone to make my electrical system the best it can be. Including but not limited to: Private transformer, 220 Volt three phase electrical drop, 750 Amp commercial bypass meter box, 16 dedicated runs exclusive to the stereo, separation of phase between digital and analog, and dedicated 12 gauge copper star grounding for each component.

With all this work, I cannot imagine music without a high quality power cord. I choose Purist Dominus power cords for my system, and the effect is so drastic, that an entire room of people laugh out loud when a stock cord is substituted. The difference is literally that big.

Do I remember you live outside of the USA? Maybe that is part of our different results.

It's true that some components are designed to be invariant of the power-line voltage. Some Linn equipment is like this, particularly when switching power supplies are used. However, in most amps, the linear power supply is not even regulated, and the capacitor bank is not infinite and the inductance from the cap bank to the output transistors is not zero, so they are sensitive to the line voltage, particualrly during high-current high-frequency transients.

I heard a rumor that the infamous Robert Lee @ Acoustic Zen is coming out with an inwall a/c powercable made of his Zero Crystal Copper to address this specific issue. I can't wait to try out some of that stuff.