recommend me good power cable , thanks

There are lots of very good power cables from a dizzying number of manufacturers today. The problem is that like all cables, how these power cords perform in your system, is dependent on what components you have and the synergy,or lack thereof, that they will produce with your gear. I, or anyone else here, could go on and on recommending cables from specific manufacturers all day, like, Shunyata Research, Electraglide, Stealth,Gutwire,Bogdan,Kimber, etc, etc, etc, and even if we knew your exact components, the truth of the matter is that only by trial and error listening to a variety of cords in your own system are you going to truly find just what PC is the right one for your specific piece in your system. Unfortunately there is no silver bullet shortcut to this situation.

..i would try a jps 'aluminata' ..i have tried most of the pcs you mentioned and the 'aluminata' is much better ..in my system...the crystal cable 'ultra' is also a great pc which has most of the strengths of the 'aluminata' and more detail..good luck

Your comment about your comparison of a high end Nordost PC to your Black Sand Violet Z1 PC is exactly why I've stuck with Black Sand PC's while the rest of my system has evolved. I've gone from just OK IC's and SC's to better, and now I've got Kubala Emotion IC's and Kubala Expression SC's. All the while my Black Sand Mark V's and Violet Z1's have withstood the test of allowing the better IC's and and SC's to stand out.

I have done a lot of experimenting with power cords. Make your own. Use either Furutech F1 series connectors or Oyeida 046 series with Accrolink cable and you will be very pleased. If you decide to go with a factory cord, do not be predisposed by any suggestion...try it in your own system. Even with the same brand of cable, your amp, and preamp may like different cables. Experiment.