Help selecting a power cord.

Power conditioners are very dependent on your location not just on your system. In the UK we generally have good clean power and I live 4 houses away from a small electrical sub-station. Probably for this reason power conditioners make no improvement, and actually make the sound worse. In the US I believe that the quality of the power is poorer and many seem to get big improvements from conditioners. But it will still depend - rural locations vs city apartment blocks will have very different quality of electrical power. 

Re power cables - there are too many brands to know more than a handful but of the ones I have heard I can recommend Shunyata. The mid-series Alpha range by them are particularly good value.

Shunyata power conditioning for me. Also on the cords. But to get real results go with alpha NR or Sigma NR level.  Both not cheap but you will get noticeable results!

+1 Duckworp

+1 Puritan PSM 156
Probably the best advice I’ve taken from Agon. Period.

Maybe this British built conditioner makes power stateside more like UK AC, well with half the voltage mate?

I’ve found that even the base Shunyata Venom V14 power cord makes a noticeable improvement over stock power cords on a DAC. I think the benefit comes from better shielding of electromagnetic interference. That could be a good starting point.

FWIW, not every "audiophile" power cord sounds good. I’ve heard power cords that made my system sound worse than with the stock power cord. Matching the characteristics of a power cord with the characteristics of your components is important to do. The Shunyata Venom seems more neutral in its effect on all equipment.

A good way to then test out more expensive power cord at low cost is to use The Cable Co's lending library of cables to see if you can hear any improvement over a Shunyata Venom.