Power cord? Why?

Here is my theory as to why they make a difference, with analysis and measurements.

Amplifiers demand current from the power-line when the capacitors in their power-supplies become momentarily discharged due to high-current transients in the music signal. This discharge condition must be quickly recharged from the power-line, through the power-supply transformer, or a voltage sag will occur. Such voltage sags can cause audible distortion at the loudspeakers. If the power-line has significant series inductance in the path from the power panel to the amplifier, this can prevent the capacitor bank from recharging in time to prevent a voltage sag from occurring at the amplifier output transistors. With a low-inductance cable, the voltage drop across the cable will be insignificant during high-current transients, minimizing the voltage sag. This allows all of the current needed by the output transistors to be supplied when they need it, resulting in fast, dynamic response to transient signals.

A typical 6-foot 14 AWG rubber cord and 25 feet of ROMEX has inductance of 7.2 uH and resistance of 235 mohms, ignoring the plug resistance effect. Therefore, the voltage drop at 20kHz will be I*(wL+R)= I*(.905+.235) = I*(1.14). With a 6-foot low-inductance cord and 25 feet of ROMEX, the inductance is 5.9 uH and the total resistance is 147 mohms. This is an 18% reduction in inductance and a 37% reduction in resistance. The voltage drop for this combination will be I(wL+R) = I(.741+.147) = I(.888). So at a fixed dynamic current I, the voltage drop in the entire power feed at 20kHz is 22% smaller with the low-inductance power cord. I would consider 22% to be significant. The reality is even more compelling. When you add in lower plug and receptacle resistance and the fact that the di/dt on the power cord will have spectra well above 20kHz with some amplifiers, the low-inductance cord makes an even bigger difference.

And please don't give me a lot of flack about 60Hz current in power cords. The currents are very high in frequency - just measure them...

Eldartford, I may be interested in that bridge in Brooklyn, but first I have to buy Viridian's open mind. Maybe, in between the two, I will mortgage my home to rewire right back to the Hydro-Québec generating facility in search of the absolute sound and of "emotion" from my system. Remember in selling that bridge these immortal words from the son of a local pawnbroker here: "money talks and bullshit walks". From a bitter, bitter man.

When Nikola Tesla discovered the AC system we have today, it was rushed into service because the Direct Current System in use had serious problems. In the process of changing one system for another, no one considered changing cabling systems because for its time, the DC cabling system appeared to work well enough.

A century later, cracks are appearing in the dam. As electrical equipment develops with greater sophistication, flaws in the cable delvery system are becoming more apparent.

At the consumer end, the old DC designs must give way to a new type of Power Cable developed specifically for Alertnating Current. Why? When AC is transferred through cable that is designed for DC, large amounts of distortion are created. Any high tech electrical device will suffer performance degradation when AC is conveyed without consideration of its unique characteristics; we call this phenomenon AC Pulse Distortion.

How is this distortion created? Every time AC switches phase a pulse is sent through the cable structure and resonates to the tone of the AC pulse. (This is what you hear when your car passes beneath transmission lines with the radio on.) Any signal, like music superimposed over this tone will instantly become modulated, therein lay the problem.

The traditional solution has been to dampen conductors by heaping large amounts of insulation on the structure. This is an attempt to solve an electrical problem with a mechanical solution...it is basically ineffective and certainly not elegant.

Through years of rigorous research, a solution has evolved and in the process a whole new technology has been developed. A breakthrough came with the realization that phase pulse intensity is controllable and that created a solution to a very large problem.

This accomplishment breaks the link between cable structure and resonance of the AC pulse. Music may now manifest in its original pristine state with no background noise.

This new advancement is implemented without the use of traditional electrical components such as resistors, inductors, capacitors, etc., because these devices are highly resonant and contribute to the problem.

Major Point: If all the essential peices of an audio system were soldered together with no cabling used, the pulse effect would continue to exist. ONLY within the domain of electron transfer (cabling) can this situation be confronted, maipulated and defeated.

Gotta say, these things make a difference. Power cords *and* outlets. I NEVER would have thought this to be the case!

Just some personal background to so you know how entrenched in the nay-sayers' camp I was. Undergrad in Physics and Math. 5 years engineering in aerospace - electrical, RF, and systems design. Graduate degree in Mechanical Engineering and an MBA. Hence, I have a background to understand the physics and bull shit marketing; this power cord stuff was nothing but snake oil.

Wrong.

If your systems has a threshold of resolution, you will hear a difference. And you have nothing to lose - most of these power cord guys give you a home trial period - why not try it for yourself?

Understand, the audio system is quite complex - from electronic design, to room treatment, to vibration management, on and on there is work to optimize the system. Take advantage of this amazing Forum and learn!

Best,

cfmartin,
try these simple exercises with the cords you already have and see if they change the overall sound of your system:

1. put the heaviest gauge cords on the most current hungry components. mine are all marked 16/3 or 18/3. 16 is heavier. the insulation can be deceiving. read them if you can.
2. route the cords away from your interconnects. by some miracle of engineering alot of cords exit their components via the left side when viewed from the front. in any case, place your power strip on the side which provides the least interaction with your interconnects. If a power cord must touch an interconnect make sure they cross one another at right angles.
3. keep the power cords apart from each other, even by an inch. don't coil any excess. don't bundle them together even if it looks tidy.
4. keep the accessible metal surfaces of the plugs free of oxidation. i use car wax but i'll bet there's something more trick to clean the copper or brass they're made of.

quite by accident, i'd ignored one or more of these simple procedures while setting up a new rack and found my system immediately sounding thin. getting all of them right restored its full body.