why the PC change the tonal on my gears.

Jmcgrogan2, I read one of your other thread and one of the poster suggested 700 hrs breaking-in for his PCs. Does PC really need time to break-in? Please, give me your feedback. I am kind of like the clean and clear with authority sound of the Prelude PCs ( good price and well-built too )just a little sharp glare in midrange and the highs is kind of too much in details and a little forwarding. I have problem listen to Diana Krall ( All for you dedicated to FN) with the Prelude while it seems very nice with the stock PC. I don't believe in either voodoo or snake oils but if after a break-in time these Prelude PCs smooth out, I will be happy to keep them in my systems. I guess my question is " does PC need break-in time or it is a myth? Thanks

Yes, power cords need break-in time like anything else. Attach it to a refrigerator or freezer for two weeks of running time. That should smooth things out and/or you will know approximately the potential of the cord.

The stock Belden cords (PC) are a good starting point.I generally find that many PCs will improve certain aspects,but in overall performance won't equal the Belden or even add brightness or darkness.The "good" PCs will surpass the Belden,but it will require some auditionig.Some have preferred the "active Pcs " for their digiyal front-ends and low-level gear,using a standard confiuration for the power amp)s).

Andrewdoan, I tried that same power cord and it changed the sound in a negative way. System sounded very dull, undefined and with rolled off highs. I gave it a full 30 day break in and returned it. You are right, the stock cords were better!

Power cords do change the sonic signature...it's just a matter of which way you want to change it. PS Audio Prelude happened to change it in a way I didn't like.
There are lots of very good power cords though. Basically, for about the same money as PSA Prelude, Shunyata Diamondback was a big improvement over a stock cord in my system. You may want to try that on your amp. Open sounding with nice dynamics and has positive effect on soundstage and overall sonic picture. Similar to Diamondback in price and sound(smooth sounding with a bit more emphasis on mids than Diamondback), is the Acoustic Zen Tsunami Plus. Both cords should be way better than your stock cords.

Andrewdoan, yes, a power cord does take time to burn in, however 700 hours seems a bit excessive. From my experiences, you usually get a good idea of how a p/c will sound right out of the box. Generally, the cord's sound will change a bit over time, as it 'settles', but I've never heard a night and day difference as some folks have said. Usually, if a cord I've heard is 'in the ballpark', it can sound better over time. However, I've never heard a cord sound forward, have sharp glare, and too detail turn into a warm, sweet cord with time.
Sometimes burn in can take the edge off, but if the initial reaction is that negative, I don't think that's the p/c for you. There are many other good cords out there. It depends on what kind of sound you are looking for. There is a thread on the AudiogoN forums called 'Power Cord Flavors'. Maybe you could get some background reading stuff like this. Sure, it is not the Bible, and opinions will vary a bit on what aspects they look for in a p/c, but it will give you some ground work, a place to start.

Happy listening,
John