Quality Power Cord

HI to everyone.

Need advice. I would like to replace stock power cord on
NAD C356DAC with the better one.
I've tried with the Signal Cable but it didn't work.
Lost highs, actually the sound became muffled with the "brushed" highs.
Any suggestions.
Al, Never mind my question. The cable just lifts the ground pin, it still is a 3 wire IEC. I'm a dummy.
I have tried following cables: Pangea AC-9mkII; AQ NRG-4;
Shunyata Venom 3 and all of them affected the sound (highs).
The best sound was with the tiny $1.00 stock power cable.
Uh, how was it that you paid $1 for a free stock cable, and why would you do such a thing?
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