Upgrading power cord.. proven upgrade? or crap?

Yes indeed power cords do make a difference, maybe some folks systems are not high enough resolution to pull the extra detail out of the upgrade. The question is, are they a good value? Most major power cords have less then $100 of materials in them the rest is all marketing, and these cables go for a few thousand dollars! that is crazy! Buy one take it apart and build a few clones and then sell the original, you’ll get the same improvement but will have 1/10 the cost into it. Not for everyone but I know more then a few folks who have had great luck with such upgrades, besides it keeps the WAF low, I think there is an additional 10% surcharge on the WAF when crazy high buck cables are purchased

If you cannot hear an IMMEDIATE improvement on ANY component with a LessLoss PC, then you should have your hearing checked or find a different hobby.

NOTE: There are exceptions for some digital pieces with certain power supplies that could care less what kind of power cord you put in - like my buddy's Wadia CD player (now sold)... we tried back and forth with a $10 stock PC and a $1,200 LessLoss PC - no difference AT ALL.

I wasn't a believer until I had a Argento Flow Master Reference connected to my Sanders Magtech amp.  It definitely was better than my Groneberg power cable.

Over the past few years I have been experimenting with building my own power cables...
- not simply adding high quality (high priced) connectors to high priced bulk cable (but I started with this approach)
- I now actually hand wind the conductors into different geometries/architectures.

What I have observed...

#1 - high priced bulk cables with high quality connectors attached provide the least improvement - but are still better than stock power cables

#2 - Braiding the conductors is significantly better than bulk cable - even when made from household romex - NOTE: romex will break is bent a few times, so don’t use this - I used romex just to test a theory.

#3 - winding the neutral and ground conductors around the live conductor in a tight helix geometry provided the biggest improvement.

#4 - for #2 and #3 their conductor geometry rejects EMI and RFI and therefore shielding is not required unless you are in a very noisy environment like a recording studio with cables all over the floor

Other observations common across all geometries...

- for the live conductor - use the best quality wire you can afford, I use conductors from a piece of Furutech bulk cable

- for the neutral conductor - reasonable quality copper conductor seems to be as effective as high quality Furutech - I use silver plated copper conductors

- for the ground conductor - Home Depot’s best multi strand house wire is good enough

- crimped spades worked better than clamping bare conductors in the connectors

- components actually run cooler using helix design cables

As for the "science" it all boils down to the inductance of noise across in internal conductors of the power cable...

For further info please read...
http://www.image99.net/blog/files/be8de0c383c5434907610d6b55049e69-75.html

Also Read...
http://www.buellinspections.com/what-is-phantom-voltage-induced-voltage/

Inducing noise into the neutral line effects the performance of the connected component(s) by increasing distortion levels - A good power cable will reduce, maybe even eliminate that effect.

I now use helix design PC’s and IC’s across the entire system and it has never sounded so good.

Hope that helps :-)