Power cables of your choice, and why?

Woo Audio is an excellent brand. Good you called them out.

They thoughtfully design their products. And their products perform well.

Imagine the power cord to be some extension of the transformer's primary in a power amp, and read up a bit on how tranformers are spec'd. If you don't have such a thing inside your amp (some class d, smps), don’t worry about it. 

The line items you list are indeed good to have for a power cable.

Four things matter in a power cable:

 

Proper shielding to control EMI/RFI.

 

A grounded shield, typically at the source end (outlet).

 

Adequate gauge — 12 AWG or larger for high current power / integrated amps, and at least 14 AWG for other components.

 

Conductors made from materials with good conductivity.

 

Please let me know if I’ve missed anything, especially something that could affect sound quality. Power cables that meet these requirements can be found at very reasonable prices in the $50–$80 range. I’ve used WAudio 10 AWG, Pangea AC-14 (14 AWG), and Emotiva XIEC 12 AWG — all solid options that won’t break the bank.

Imagine the power cord to be some extension of the transformer's primary in a power amp, and read up a bit on how tranformers are spec'd. 

@deep_333 

Brilliant! You've got it right! Thanks for posting. 

Imagine the power cord to be some extension of the transformer’s primary in a power amp, and read up a bit on how tranformers are spec’d. 

@deep_333 

Brilliant! You’ve got it right! Thanks for posting. 

Seems brilliant, but let’s scrutinize this analogy a bit. A 12 AWG power cable has about 0.00159 Ω/ft of DC resistance. Over 2 m, that works out to roughly 0.01 Ω. A typical 400 WPC high-current Class AB amplifier (60% efficiency) draws about 5.6 A, so the voltage drop across this resistance is V = IR = 0.056 V.

On the transformer side, a typical single-phase transformer has about 5% regulation, meaning the voltage drop at full load is around 120 V × 0.05 = 6 V. In comparison, the voltage drop due to the power cable resistance is only about 1% of the transformer’s own regulation.

This shows that the analogy does not hold up in practice—the cable’s effect is trivial relative to the transformer’s design limitations.

Still, I like the analogy.

@lanx0003, in response to your question, among the things you have missed are

Design and construction of the mains and IEC connector and the manner in which the cable is terminated into those connectors;

Design and construction of the cable dielectric;

Mechanical construction of the cable overall with respect to microphonics.

I was comparing $50–$80 power cables to high-end counterparts costing more than ten times as much. Is there any evidence that well-made cables like Pangea or Emotiva lack quality components or construction?

Second, I agree that dielectric properties matter, since capacitance is directly proportional to the dielectric constant. However, this is relevant mainly for audio signal quality in digital or analog interconnect cables. The effect of a power cable’s capacitance on audio signal quality is almost negligible. We’re talking about a few hundred picofarads in a typical 1.5–2 m power cable compared with tens of millions of picofarads from the capacitors placed before and after the regulated power supply.

Lastly, regarding the mechanical construction of cables: I’ve already discussed shielding and dielectric. For other mechanical properties such as vibration control and damping, check out the beefy power cables from those three brands (with thick jacket/filler/dual shielding). See how tight and rugged their build is before you judge how well they might reduce or eliminate vibration.