You're in Singapore if I'm not mistaken, so I don't know if The Cable Company will be able to assist you with their lending library of cables.
You've said that you have a Pass X250.5 amp and are asking about good preamps in your other posts. So you do have good equipment, and like HEW stated, a revealing system allows for the better reward with higher quality cables.
The question that everyone here talks about is: does high quality also infer high cost?
I once had a high quality system that consisted of an Accustic Arts CD transport and DAC, a Herron tube preamp and Herron monoblocks. I used Stealth Indra interconnects and it sounded really good. A tube went out and blew both monoblocks (my fault for the second monoblock blowing trying to diagnose the problem because I wasn't familiar with tube gear ).
Anyway, when I sent the Herron preamp and amps in to be repaired, I brought my old B&K preamp and amp out of the closet. I hooked them up using the Stealth Indra interconnects and I couldn't believe how good they sounded!
So, it seems that hooking up even modest components with high quality cables will show you how much better they actually are than what we expect out of them.
That brings us back to high quality versus high cost. I haven't listened to new cabling less than $500.00-$1000.00 for so long, I don't know what's out there. There are plenty other members making recommendation that are worth exploring.
I will say this, I've gotten rid of all of the backup cables that I had with two exceptions: a set of anticable speaker cables which aren't even broken in, so I don't know how good or bad they are, and a 40 years old set of blue Nakamichi unbalanced interconnects that I will never get rid of because they're still that good.
Being in Singapore, you may have to buy to try cables. Elizabeth is a very trusted member and has a very nice system, so the Pangea power cords are worth trying for sure.
I would recommend trying these power cords: http://app.audiogon.com/listings/ac-cables-running-springs-hz-crown-jewel-power-cords-15-amp-excellent-condition-2012-11-06-power-92691-mission-viejo-ca
It is a very good power cord that I used myself until I went up one more step to the top of the line X20. The Running Springs Crown Jewel HZ is actually a CH Acoustic X15.
If you like it and decide to move up to the X20 at a later date, the X15, or Crown Jewel HZ, works great on your TV!