why the PC change the tonal on my gears.

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

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.
Jmcgrogan2  (Threads | Answers)

I agree. I have always heard the effects of power cords immediately upon installation. If it doesn't sound right at the outset, it's not going to sound right 500 hours later. This is not to suggest burn-in doesn't occur. I just don't think it's that important to the overall synergy that a cord has or doesn't have with a particular component.

Thanks, guys. These power cords need to go then and the search for audio nirvana shall continue...Best regards,

Try the inexpensive Volex 17604 sold at Carlton-Bates.com. $5.81/ea in quantities of 2 or more. It's a silly good cord at a ridiculously low price. A good place to start.