Designer power cables

Ive reached the point with my system where I should do something about installing better power cables . There are a few points that need to be clarified though and the first being , and looking at the PS Audio power cable with the varying shapes of conductors to deal with different frequencies . Aren’t we dealing with one frequency and that is in my case 50 Hz ( mains freq .) or am I looking at this issue from the wrong angle . The next issue is the number or cables required , I have a P5 power regenerator do I need a power lead for the incoming as well as the four outlets , and if you say " yes " for the incoming power why , doesn’t the P5 deal with the noise issue on the line .

BHK Pre and 250 power amp DS DAC PWT P5 Avid Diva SP II ASR Phono stage SME arm Consensus Lightnings Synology NAS

All good questions. Indeed, when dealing with power the primary frequency sent to equipment is 60Hz in this country, 50Hz in others. So why make cables with different construction for frequencies other than the low frequency fundamentals? It’s a really good question, one I have often asked the designer of our power cords about and get a shoulder shrug. My speculation is that quick demands of power in musical applications are much faster than the fundamentals - so we need power delivered quickly. I can see some of that using a current probe on the scope, rather than a voltage probe. Current is demanded quickly, much faster than 50 times a second and perhaps this is why that sounds better.

The second question concerns the input. If the Power Plants rebuild the power, why feed it well? That’s not hard. Think of a regenerating plant of any kind, even one based on converting water to steam and back again. The quality of the source feed determines the system’s ability to respond to demand properly. Too small or restrictive a cable on the input and the regenerator cannot properly do its job.

What Paul is trying to say…is CURRENT demand outstrips all else. This means VERY low inductance values in the cord. That value is conductor variety indifferent. Various sized or shapes or one if the total inductance is low, it does not matter except to marketing. Current will flow through the lowest impedance path down the cable so technically, the BIGGEST wire you can use, and with the LOWEST inductance is the best MATRIX solution. Many smaller wires with a low total CMA allow some tricks to be used…but it costs more.

This also means INDIVIDUALLY insulated wires, too, in each polarity in the cable. Short them out and you can’t manage the capacitance with two large surfaces parallel to each other…and it prevents magnetic field cancellation properties. Not that a cable that BENDS is a bad thing, either.

The capacitance of a power cord is not an issue as long as it is within reason. A capacitor discharges current VERY fast and the power cord acts like the caps in your power supply…they store “current” as a capacitance and instantly give it back on demand from the device’s power draw with super low inductance.

One aspect of shielding quality is seen as the L and C values. Are they exorbitantly high or as good as an unshielded cable? Shielding can’t actually be better, all else the same, to unshielded so you better really need it or it isn’t a benefit. You can passively mitigate EMI by conductor orientation for a good compromise, though.

Right now, it seems that FUD is all on EMI/RFI. Truth be told, our stuff is responsible more for it than we need to protect against it. Also, EMI/RFI is very high frequencies as materials that a magnet won’t stick to won’t shield low frequencies…like 50 Hz or 60 Hz. Braids and foils shields are 1 MHz and up, with 10 MHz being more like it. Graphite, carbon fiber, and like materials are also high frequencies…even as high as 3 GHz and more. The low permeability frequency of materials describes when a material will allow a signal to travel within it (low impedance path) verses ignore it (too high an impedance path).
The PROPER science is using wave cancellation by orienting the fields with the right permeability materials. E=I*R in essence says we want a LOW resistance shield so the shield current does not create a very large voltage to ground reference. The more current we remove with electromagnetic cancellation, the lower the voltage in a given resistance shield.

Shield remove EMI/ RFI by reorienting the electromagnetic waves that travel in the shield from the cable core to the shield. The field in the shield can ALSO be reorient for cancellation a second time. This is sort of like how a shield on an XLR cable works, it REDUCES the energy that reaches the next level, as the next level in an XLR is not always a “perfect balance”.

Look for very low measured inductance as this is the best known metric for current delivery. Sure, slightly higher inductance with MUCH higher cap may possibly allow a “storage” surge type advantage for a short time…like a big cap in a power supply offsets some series inductance in the supply. But this graph of how long and exactly when this is an advantage has never been made that I’m aware of…I KNOW low inductance ALWAYS works with ANY capacitance.

For what it is worth, those are my thoughts. Until I make it, trust those that do.

Galen Gareis


Thanks, Galen! What numbers should we be looking for with regard to low inductance?

ZERO is the target! But something around 0.2 uH/ foot or less is low. Lower is better, of course.

Be careful on shielding. It is only a benefit when the negatives are less bad using it than the positives. This is always true on any cable, even the simplest design, a coaxial cable. The shield geometry, controlled by the core concentricity, determines how well the cable electrically works, with or without external noise.

Galen Gareis

I just spent 30 minutes looking to see which power cables have good measurements per your targets. Apparently, these measurements are not being done or, at least, the specs are not being published on web sites. I looked at some well known companies: Shunyata, Synergistic Research, Analysis Plus, which came up on a Google search for power cables with low inductance. I couldn’t find any published specs on inductance. Very interesting. Anybody know of a company that shares these specs?

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Zu Audio does but I don’t think they are in the same league as Shunyata, etc.

If inductance is king, why not simply use non-shielded 10 or 8 awg THHN copper with decent ends? Simple to make and try.

lIke this:

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I think people get too wrapped up in numbers and noises that are meaningless, if musical sound quality is your goal.
I’ve tried all the cables mentioned here. I don’t know what the numbers are and I don’t care. All I know is, of all the power cables I’ve tried, Shunyata sound significantly best to me. And if I learned that their inductance numbers weren’t the lowest, it would mean nothing to me.
Same with Iconoclast IC’s and spkr cable. The best, end of story for me.

@RonP - I love Shunyata Research power cables. I have been replacing all my PSA AC12 cables w/ SR Alpha NR (8ga) cables. In addition I added the SR Anaconda CX (6ga) to my P20 after I went 10/2 single run romex to the SR BLUE out let just for P20. I took my AC12 cables and added them to my (4) Sbooster LPS. Shunyata Research is made in the USA and tested in USA. There are some really good papers on their test and design methodology on their website. It discusses dynamic current test methodology as Galen mentions above.


Trust me on this one, people who DO indeed pay attention to the physics for you will make better sounding products. True, the customer should not have to worry about the proper use of technology but the market is a buyer beware environment.

Galen Gareis

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I agree, Galen. But since I understand only 43.3% of what you say, I’ll leave the scientific development to you and trust my ears to agree or not.
You’re cables are clearly best in my system but I couldn’t explain why because I don’t have the knowledge base. I just appreciate that you’re out there doing this!

AQ cables are pretty good too. As are Black Rhodium (esp for the price) that is if you can get them in the US. My biggest problem with these premium cables is that they are often very inflexible and plugging them in can be a difficult job (esp with UK plugs that are at 90 degrees to the cable) . I have a real job getting them in to my P20 and P10.

@drarifakhtar - SR Alpha NR cables are 10X more flexible than AC12…

Thanks I will definitely try them next as the whole flexibility thing is a real problem!

@drarifakhtar - I wish they would have a better connector. Half the battle is the connection on most of these power cables is where the issue lies… the contact area, retention…sucks…

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There are a lot of unusual claims on cables, and power cables are in the thick of it. An RG59 sized coaxial has higher attenuation than a RG6, and more than an even larger RG11. Why? At low frequencies it is total CMA area dependant, and at higher frequencies it is SURFACE area dependant. LARGER wire will increase BOTH of those, lowering attenuation at low and high frequencies. This is how it fundamentally works as RF.

A power cord is 50Hz to 60Hz. These low frequencies are diffusion coupled through the wire cross section, it is not music, it is not RF, so there is no need to improve current coherence by using smaller wires…but a BUNCH of them to lower DCR and manage electromagnetic cancellation.

We have a power cables with two or more wire sizes and shapes. The majority of the current will go through the LOWEST impedance path on a polarity. This is defined by the CMA cross section of each wire. Shape is meaningless at 50Hz and 60 Hz. The current will divide based on the ratio of resistances of the wires in parallel. The voltage will be the same across each wire.

If there WAS a such a thing as, “high frequencies” going through a power cable, they would go through the LARGEST surface area wire, not the smallest as that is a lower impedance with the most surface area (see the first paragraph). The small wires in the cable are worse for the 50 Hz and 60 Hz signal as they are low CMA area high impedance paths, and worse for even a “theoretical” higher frequency path looking for lots of surface area, bigger wires.

Why are they in a power cord? I don’t know, nothing supports this except marketing. They HURT the performance by creating unbalaned current paths in the cable. You want the total CMA cross section of each polarity to be the same, and the current in each wire of each polarity to be the same. This means ONE wire size in each polarity and the same CMA area between each polarity.

I mentioned in an earlier post that yes, you CAN use more smaller wires in a power cord to passively reduce the electromagnetic field in the cable to mitigate shielding. BUT, this means putting MORE wires in the cable much like RG59 cables in parallel to reduce attenuation to be like an RG11. For RF it is easier to use the larger cable. In a power cable low inductance and low electromagnetic properties are not going to both be optimized and reached with just two big wires. True, this is the cheapest design that does OK, and we use it every day. But to fully optimize the design means individually insulated wires with smaller cross sections to ALSO address other electromagnetic issues like lower inductance and magnetic fields.

With MUSIC, that DOES have a wide frequency range, we have a different set of problems superimposed onto a power cables requirements. That is the issue of current coherence, forcing the near same current through a wire at ALL frequencies. Power cable doesn’t have that problem, yippie! Across mutiple frequencies you can do this only one way, use smaller wires. But, DCR is still important so we need to use LOTS of them. Does current coherence matter? My studies of isolating variables says it sure does, and that was a downer as it is so hard to do and not screw the pooch everywhere else in audio cables.

Correctly made cable does not need marketing or sales to work! Physics is it’s own boss.

Not so easy to manage L and C with many and small wires. The lower DCR reached with many small wires utterly destroys most geometric designs reactive variables. So mission control, physics, is not happy enough about that.

My argument is that there is not enough of a concern for getting wrapped up in the numbers. Physics is not marketing, IT IS INDEED what you are buying. We need to pay attention to that. There is virtually no way to know what you are getting without the numbers and calculations. Ask for them.

My opinion on a design is driven by the physics. How it works can’t hear marketing or sales telling it what do to match our “story”. Good cables have no story, only measurement or calculation algorithms based on measurement.



The graph of IEC plug contact heat with respect to current, referenced to a shunt, can show the deficiency of the IEC design. The pull out force, an indirect value for resistance through the plug, is very poor. It is a weak link by far. But, this is what we have to work with.


I haven’t used one, but the SR power conditioners have a little collar under each connector to hold them square in, to avoid sagging and possibly falling out.


@rower30 - I see the IEC plug as the weakest link. You go through all the trouble of designing a great power cable and you have this crappy connector. In addition you have this IEC filter in most electronics we never discuss. What is it’s role, how does it affect dynamic current? Should it be differential and or just common mode… is the size inductor big enough… is the insertion loss for lower freq acceptable. Do you need it if you have very clean and well managed power with a great cable already?



That circuit is designed to keep stuff from going OUT the power cord and failing FCC class one and two emissions. The consumer side is stricter than the industrial side. If a device can pass the FCC market requirements with a plain power cord, I think you may see it omitted ONLY if the power cord is “bare” and has no collar ferrite inductor at the plug to also block RF from going down the cord.

If that ferrite inductor is needed on the power cord, and/or the power cord can be removed using a different cord the FCC will revise the test to the worst case set-up.

Only if the device can pass with no special power cord COULD the internal RF blocking circuit be omitted. Some may require just a simple internal circuit, this can be a capacitor to ground. The worst case will always pass.

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