Originally Posted by unpainted huffheinz
These threads wouldn't exist if people knew what power transformers and phased locked loops were.
The transformer that takes the high voltage AC to ultra low voltage DC completely synthesizes the DC power signal. Also, the DC pulse trains that digital circuits use exactly resembles, wait for it, the most awful, dirtiest AC signal possible.
Most audio equipment uses linear power supplies, so they use a bridge rectifier and big caps to make DC. More things use switching power supplies these days, and there are techniques you can use to not deal with the noise a SMPS generates. Nevertheless, the rectification induces >100% distortion on the waveform.
Also, in the circuit, you have voltage regulation that cleans up the power more, and isolates the wall from the circuit ... if it's designed correctly. And it's yet another reason power cords don't matter as far as clean power delivery goes.
Originally Posted by Artisan Fan
Shunyata has a good summary below as follows:
That's a pretty terrible summary. It's too bad you just copy-n-paste crap instead of thinking through the claims for yourself to see if there is any correlation with reality or even with the subject matter at hand.
MISCONCEPTION #1: AC power is like water coming from a large power tank, flowing through several 10s of feet of power hose into a component. This implies that the component is at the end of this system.
Total strawman. Some aspects of electricity have a direct analogy to water flow. Others don't. Nevertheless, this aspect doesn't really address why power cords should or shouldn't sound different.
MISCONCEPTION #2: AC power can be contaminated just like water in a hose. This implies that once the water is contaminated at some point up stream, that is must be cleansed before it arrives at the audio component.
Another strawman, except this one contradicts itself. AC power can be contaminated, and AC power cannot be contaminated? Make up your mind! Also, well-designed components have high levels of EMI filtration. Those that don't are susceptible to wrapped tin foil.
Some power cords for example, use capacitors, inductors, or ferrites in an attempt to control the EM fields around the audio component. The success of such an approach is completely dependent upon the specific power supply design and its reaction to the added reactive capacitance of the power cord.
That's right, but I'm not sure why they said this, since this completely debunks any special filters, shielding, or filtering properties of fancy power cords. To have a chance at proper filtering or shielding, the power cord must be designed with a specific power supply input impedance in mind. This is also why balanced power doesn't work as well as it does on paper.
A well designed power cord can act as a noise-isolated extension of the primary winding of a component's power supply and will help isolate the power supply from the fields of radiated RF and EM noise energy that is ever present in all electronics systems.
If you believe what they wrote before, this couldn't possibly be true. More self-contradiction.
A primary source of audible sonic degradation is caused by the power supplies. Most components use FWBR (full wave bridge rectifier) power supplies that generate an incredible amount of transient noise when the rectifiers switch on and off. The design of a power cord can significantly affect the reactance of these signals within the power supply.
Another self-contradiction. You cannot possibly design a power cord with predictable filtering capabilities without knowing what power supply you're going to use with it.
MISCONCEPTION #5: There is some conspiracy among audio designers that keeps them from producing a "proper" power supply that is not affected by the quality and design of a power cord. This concept is like saying that if a speaker were properly designed, you wouldn't need to use a good quality speaker cable.
Strawman. Speaker-speaker-cable interactions cannot be avoided unless you have superconducting cable or infinite input impedance on the speaker. Electrical power supplies however can be designed to ignore the vagaries of wall power.