The influence of power cables and phase orientation on the sound
Power cables can have a significant influence on the perceived sound of your system. But did you know that the phase and position in the extension block also matter?
So, power cables make a difference in sound?
Why would it matter while outside of the house there are literally hundreds of kilometers standard wire in the power grid? There are lots of theories but precious little proof. All I can go by, are my ears.
While as audiophiles we focus on the last few meters of cable in our houses, the kilometers before it are, of course, also essential. No-one I know has asked the power company to change the cable to their house for an OOC cable and neither should there be a need for this. As long as they are of sufficient capacity for the required load, everything will be fine. Purely theoretically, as long as they meet the required specifications, those last few meters inside the home will also not have an impact on the quality of the sound, no matter the material. But here’s where it gets tricky. Although you’d have to go really crazy to cause an actual voltage drop, many experiments have shown that variations in the last few meters do cause audible differences.
As I found, the cable’s geometry and the type of dielectricum and the cable’s outer sleeve often have a larger effect on the sound than the type of conductor material.
The Final Meter
Is the final meter really the most important and as it follows, the meters preceding it less so? I don’t think so. It’s just that we have the possibility to experiment with these final meters and many audiophiles have noticed that the sound can be influenced by different types of power cables.
As I mentioned, I have observed the largest differences when comparing cables that have different dielectricum- or sleeve materials. Copper versus silver or what-have-you exotic conductor materials can certainly lead to audible differences but these are overshaded by those caused by the plastics surrounding them. I am not a technician but most likely these are effects caused by capacitance but in any event, the audible differences have little to do with the absolute quality of the materials.
Cables with very thick layers of PVC such as the Lapp 110 or 191 in my experiments always make a component (or the system) sound fatter, rounder and woolier. Depending on the cable that is compared with, the Lapps can also sound smoother or subjectively more pleasing. Cables with a geometry that allows very little contact between the conductors and the surrounding materials, on the other hand, tend to sound fast, open and direct. And when coming from a “smoothing” cable such as a Lapp, these cables can sound “hard” or unforgiving in comparison. Similar differences can be heard between materials such as PVS versus PE or Teflon and, as one can imagine, natural materials such as cotton also have a certain effect.
I have tried pretty much every power cable that can be found in bulk as well as a very large amount of after-market, high-end power cables. It is not my intention to discuss all of the variables and there is certainly too much to say on the subject of high-end power cables. If you want my opinion on these then please have a look at the review section. Suffice to say that I have tested cheap, expensive and very expensive power cables and, yes, there are differences every time.
One pitfall to look out for is cables that sound much more refined and sophisticated than most others. At first, this can be a revelation but over time, one can start to notice that some propulsion and expression have gone missing from the sound. My position is that power cables can never enhance every single aspect of the sound. It’s always a balancing act: improving one aspect (sometimes merely subjectively) at the cost of another aspect.
When matching power cables with audio components, it’s mostly just a matter of deciding if the yielded differences are improvements and indeed if they are worth the asking price. In certain cases, it can make sense to spend a large amount of money on a power cable if it perfects an otherwise already almost perfect system. In other cases, you might be better off using standard good quality cables with good connections and spend the money elsewhere.
My personal audio journey has led me to all corners of the cable industry but these days I have made things simple with respect to power cables. I use the same Belden 19364 with a particular connector combination that sounds the most neutral and refined to me without making the sound too polite.
Some components are less sensitive to this than others but I have yet to find one that is 100% immune to the influence of power cables. It’s always worth just experimenting with this. You can tweak a component’s sound by ameliorating certain aspects or by accentuating other aspects. In essence, the idea is to find the best balance for a given system. However, it remains important to note that there are many more factors that influence the sound of the system as a whole such as the loudspeakers and their placement and of course the room acoustics. Adjusting the sound of audio components using power cables can work but it need not always be the best method. In many cases, it is better to improve the room acoustics, adjust the positioning of the loudspeakers, getting different speakers or a different audio component.
The order of the connectors in the power extension block
It is worth experimenting with the order of the connectors in the extension block. Most extension block outputs are internally wired from one to the other, rather than each being connected to the input directly. The cable entry point is connected directly to the first outlet and from then on that outlet feeds the next which feeds the next, etcetera. This means that visually speaking, the first component has the most direct connection and every sequential component is down one position.
With respect to such extension blocks, some people claim that it is best to connect the most power-hungry appliances (amplifiers) to the first outlet. Others claim that this is not wise as the amp consumes all the power, “starving” the other components after it. Electrically speaking, neither of these theories will be valid. But in practice, there really are audible influences and once these are identified one can use them to their advantage.
In my experiments using a Popp aluminum-case, good quality extension block with brass strip conductors, I find that the first position sounds most sonorous and the most vital and the ones after that increasingly thinner and grayer. This is with no other components connected to it.
When other components are also connected, the aforementioned difference remains but is altered by influences of the other components. For instance, many components with linear power supplies have a “damping/filtering” effect that is most obvious with the component that is positioned after it. That component can sound a little less articulate or impactful in this position. When connecting it in front of the aforementioned component, however, much of that effect is mitigated. Of course, all components have an influence on one another, to some extent. My suggestion is to find those that are most severe or unwanted and to try and minimize them.
One way to counteract these influences, or at least to make them work out equally for all the connected components is by using a Star-Wire connection scheme.
Power plug orientation is also audible
The phase is a not to be underestimated factor for the resulting sound. Of course, this is only applicable for those countries that use reversible connectors so, sadly, the UK and US don’t apply, unless one is willing to change the wiring on the inside of the connectors. But if you can, just try it out: swap the orientation of the Schuko connector in the extension block and listen for changes in forwardness, articulation and speed. Most likely, you will hear a difference. One position will probably sound more lively and upbeat than the other. Never mind for now which is better. If you want to take the easy way out, just choose whichever pleases you most.
Then there is such a thing as the correct phase, assuming the manufacturers of the cable and component have followed the standards. In that case, the IEC end of a power cable and the male connector in the component should already have a matched pinout connection. All you need to do in this case is to make sure that the schuko side of the cable is oriented in the proper position in the extension block.
Finally, please note that power cables, especially the thick-PVC Lapp types, can also have an effect on the overall audio setup, even when they are only connected to the audio system’s extension block and not to any receiving component. This goes some way toward explaining why a device that is not normally expected to be sensitive to this can still sound different depending on the power cable that is used.
How to identify the correct power phase?
Method 1: By ear
By default, I tend to say: use your ears. Especially because the correct connection doesn’t necessarily have to match your situation, components or preference. But if you have many components this can be a lengthy process. That’s why I provided the following easy procedure to at least make sure that all cables are connected in an official way.
Method 2: Assuming the components are wired correctly
The official method for phase connection is as follows: Looking at the IEC connector from the bottom, having the lump on the underside, the left hole should be live (phase). See also IEC connector types and correct phase. If you don’t want to do further testing, just connect everything this way and you’ll have the majority of the components connected correctly.
The above schematic shows the cable end connectors, not the ones inside the audio component
Now that you know where the phase should be, insert the cable into the extension block en use a voltage meter or a simple screwdriver with a lightbulb to find where the phase is in the IEC connector. When the phase is at the wrong side, just reverse the schuko in the extension block. Repeat these steps for all power cables. Then you’ve done your part. Hopefully, the manufacturers have done the same. Usually, they have, but not always. I’ve even found 2 matching mono power amps wired up opposite! That’s why you’re best off doing it by ear. If you like measuring, there’s method 3.
Method 3: Measuring
For this, you need a sensitive multimeter, a grounded outlet and a non-grounded mains outlet (or use a cheater plug).
- Disconnect all components from each other (interlinks as well) and the power.
- Connect 1 component to the unearthed outlet, still not connected to the others.
- Measure the voltage that exists between the earthed outlet’s earth and the chassis of the component you’re measuring.
- Reverse the schuko connector and measure again.
The lowest measured voltage indicates the proper phase.