Upgrading power cord.. proven upgrade? or crap?

Completely agree with stringreen. Powercords are more noticeable than interconnect or speaker cable. They make profound differences too, but the powercords are HUGE. Try one of the dozen from Purist Audio Design. Extremely effective.

Absolute crap but if you want to waste your money go ahead. Google expectation bias before you do. 
And yes I have tried a few. 

"I see a few posters here recommending plugging your amp directly into the wall socket. Isn’t that risky? How do you protect your equipment from power surges if you forego any kind of surge protection?"

Hi arafiq,

In almost 50 years of audio, I never had any audio equipment damaged by electrical surge, only a TV that was hit through the cable line. YMMV.

Most "surge protectors" use cheap sacrificial MOVs and the rest of the parts are not audio quality either. They act as chokes to the virgin AC flow. Over time, the MOVs, being sacrificial, degrade to the point that they do not function anymore. The "equipment replacement warranty" associated with those products will give you some idea of the statistical life of the MOVs. After that, the surge protector is simply a placebo.

I am NOT saying that several of the best power conditioners do not help improve the sound of a resolving system (they most certainly do IME and it is not subtle), only that "surge protectors" can seriously degrade the sound of a good system. Results vary by system, the product used, etc.

Why not try plugging the PC to your amplifier directly into the wall, play some cuts that you are intimately familiar with, and see if you can detect any difference in the sound? Just don’t let your components get cold (quick changeover) between transfer of the cords.

Let us know what you find.

Best to you arafiq,
Dave

The right way to do lightning and surge protection is with a surge arrestor at your power service panel.  Home Depot has panel-mounted arrestors for ~$60, and external (if you don't have room in the box) for ~$110.  Protects every electronic device in your home, including the stereo.  
analoglvr: you are allowing your bias against AC cables to miss out on this huge facet of improving your audio experience.  I've heard plenty of bad AC cables, but if you hear a good one, such as a Purist Audio Design, and listen, I'd be surprised if you didn't enjoy the improvement in everything.

herndonb

The right way to do lightning and surge protection is with a surge arrestor at your power service panel.  Home Depot has panel-mounted arrestors for ~$60, and external (if you don't have room in the box) for ~$110.  Protects every electronic device in your home, including the stereo. 

Sorry, but you're mistaken. Service panel devices such as those from Leviton and Square D are not designed for lightning protection. For that, they make separate devices that are mounted onto the utility's meter pan, between the pan and the meter. Some electric utilities forbid the use of such devices, which is the case where I live.

That doesn't mean that panel-mounted surge protectors aren't worthwhile, however - but they  just part of the solution to potential electric problems. And at least in my installation, they are not a substitute for a good isolation transformer, or two or three.