An electrical engineer on how power cables can impact sound quality

Sharing an fascinating discussion of how the design of power cables can impact sound quality of an audio system from an electrical engineer that does analog design for audio equipment.

The HiFi Podcast with Darren and Duncan / Radio Frequency: The 800MHz Gorilla

The discussion of how power cables can impact sound quality starts at 80 minutes into the podcast

From the Podcast:

"If you have an engineering degree and you’re hearing this and you’re shaking your head and you’re saying this is nonsense, my response to you is that you’re logical. Based on what you have learned, I completely understand your response, but unfortunately, the way that power cables operate is not the way that we were taught in electrical engineering necessarily."

"Power cables were always thought of as series devices. If we add this 2 meter power cable to 2 miles of powerline, why does this 2 meter power cable make a difference?"

An intro into the theory behind why power cables work from the podcast:

"The power cable is not necessarily a series element of a system. The parallel elements [of a power cable] and way they interact with RF in the room in a common mode sense to ground is incredibly important." [Meaning in parallel to ground]

My paraphrase of the rest of the discussion. They get into far more detail: The configuration and materials used in a power cable matter because they affect a cable’s capacitance which in turn changes the cable’s impedance. Most importantly, the change in impedance impacts electrical signal differently across the frequency spectrum.

Two ways to get more details on this:

  1. Listen to the podcast starting at 80 minutes into the podcast. The discussion of how a cable's design impacts its ability to shunt RF to ground starts right there.
  2. Send a question to the hosts of The Hi Fi Podcast. You can find their email on their website.

Credentials of the creators of The Hi Fi Podcast:

Darren is the designer of many products for Boulder’s PS Audio brand, most recently known for Stereophile’s choice as the 2020 “Analog Component of the Year,” the PS Audio Stellar Phono preamplifier, and the incredibly well-reviewed new Stellar M1200 tube hybrid mono amplifiers.

With a career as an analog and digital circuit designer spanning two countries and several of the most well-known brands, Darren brings much experience to the table. He earned his EE and worked for both Bowers & Wilkins and Classe Audio before coming to Colorado, and also, before turning 30.

He is the designer of the PS Audio Stellar Phono phono preamp

Duncan has recorded 150+ bands, has published 450+ articles, columns and blogs and is an experienced DIYer when it comes to audio equipment and speakers. He met Darren when working as the Retail Sales Manager of Boulder’s PS Audio, and the two collaborated on an audiophile recording and concert series called “Invisible Audience,” not to mention the weekly hikes in the mountains. He is a mastering engineer, cable designer and musician, avid fly fisherman, bike polo enthusiast, husband and dad in his “free time.”

But what truly gives him a useful perspective for the podcast is his day job as a testing technician for the world’s largest online re-seller of high end audio, The Music Room. Over years in this role, he has listened to and evaluated thousands of the finest products from all over the industry and throughout high end audio’s extensive history.


It so easy to call someone dishonest. But in dozens of episodes they have testified to what they have heard, in a variety of systems, over years. They not only offer their listening experiences, they have offered a slew of arguments and hypotheses as to what might be going on.

There is a lot going on in a hifi system. The notion that what they have offered for discussion and debate can be dismissed as "unscientific" or as "self-interested" is, as a theory, lame and lazy.

Darren and Duncan deserve more credence, and their ideas deserve intelligent discussion.

They so talk a bit about the products of their respective employers, but most of their discussion is about their work and their own experimentation.

I love that their discussions are inspired by their listening but grounded in the science. It's interesting to hear that even with their education and hands-on experience, sometimes they can't explain an audible difference in sound quality. 

And for those who say that there is no way difference of cables can be perceived because of electric laws taught in school, remember that we listen with our own listening and Ears history but and it is important with the ACOUSTIC controls and treatment of a specific room...What we hear listening is related to that ALSO....

We dont l;isten to cables, dac. amplifiers and speakers ALONE but to the room with our own habit and listening history...

I can hear the impact of a piece of shungite put in my electrical grid... Then ...

There is something here ....

Laugh if you cannot devise your own experiments, i will only smile.... 😁😊

@erik_squires That's part of their explanation, but the cable configuration and dielectric material affects capacitance of the power cable. How this  changes  the impedance of the cable is part off how power cables are designed to shunt RF to ground more effectively. This is due to impedance hindering the transmission of electrical signals at higher or lower frequencies to differing degrees.


Sure, we can talk about different power cables having different capacitance values, but the effect is greatly maximized by shielded cables.

As for the dielectric material, I’m completely unaware of any dielectric changing the capacitance of a cable, alone. AFAIK all of the physics is due to the amount of conductive and insulation material and the distance between them. In other words, there’s almost no value in exotic dielectrics in a power cable, and shielding matter more. If you want higher capacitance cables, make thinner insulators. Now having said that, different insulators have different voltage and temperature ratings, so in this sense, I can see high tech insulators could lead to thinner insulation and therefore increased capacitance and noise cancelling.

Yes, twisting your wires can improve common mode noise rejection, so cool, let's all twist our wires and add extra shielding between conductors. 

I guess my point is, I see little point in getting exotic with power cables when solutions are fairly well understood and cheap.

“That’s not an argument. It is simply contradiction.”

”No it isn’t.”

”Saying “”No it isn’t “” isn’t an argument.”

”Yes it is.”


PS Audio doesn't produce power cords , though they did in the past...though they do recommend and sell AQ cable products...

More malarkey from people who have a vested interest in selling expensive power cords. There are NO audio signals going through power cords. A component's sound starts with its power supply - not with the wire to the AC outlet. RF interference is an overblown nonfactor.

Heard nothing that convinced me to buy a zillion $ power cable.  I'm already sold on using a very large gauge power cable. --Jerry

I have seen other interviews with Darren who strikes me as very earnest. Thanks for the link. 


From the website of a manufacturer of industrial cables: 

There are a number of ways to reduce the capacitance in cable design including:

  • Increase the insulation thickness
  • Decrease the conductor diameter
  • Use an insulation with a lower dielectric constant

A listing of dielectric constants:

Two dielectric materials used in audio cables, teflon and cotton (with a high percentage of air relative to solid material) have lower dielectric constants closer to that of air and to the ideal which is a vacuum.

It’s been a rough week for the believers in power cables and interconnects, that review from Amir on audio science research didn’t help PS audio much and then the news of high Fidelity cables office looking like it was ransacked/going out of business. I’m sure that these two guys are very nice but unless they can show graphs and readings from proper Scientific equipment , what’s the point in even going over all this again? Maybe the truth is finally going to get some sunshine.

Two dielectric materials used in audio cables, teflon and cotton (with a high percentage of air relative to solid material) have lower dielectric constants closer to that of air and to the ideal which is a vacuum.


OK, so it sounds like for power you want HIGH capacitancve, so using teflon is bad. 

Yes, when I was thinking of teflon and cotton that was in respect to speaker cables.

It's unlikely that decent power cables or speaker wires are going to experience transmission line problems.

I know first hand power cords can indeed make a very noticeable difference in detail ,soundstage and tonal balance. Having owned a Audio store for 10 years until 09 , and had cables of all prices . First make sure your power is clear ,dedicated line ,line conditioning , quality copper gold wall  outlets .

the power cords need quality connectors very important like Furutech,or WBT, 

dielectrics ,,and conductors too do matter as well as design geometry. Those who think a quality power cord ,vs say a stock power  cord or low cost $100 don’t make a noticeable improvement then they are tone deaf or too cheap to spend the money.

i speak from expertise over 40 years , most didnot have a Audio store to compare electronics and cables of from $ hundreds to $ thousands. 
even when a cable or power cord  is better where do you stop  spending,and diminishing returns in cost ?

I feel personally  for $4-5k that is plenty to get all system Cables , line conditioning too can cost several $/thousands.

I do not question whether power cords can improve audio system performance. As John Atkinson once said, ‘that way lies madness’. 

My concern with this whole schtick is that power cords can only offer marginal difference, if at all. The absurd prices people pay for power cords boggles my mind. Yes I know, each to his own, its a free world and all that. But the vast majority simply can not afford to be so wasteful. Up to perhaps a couple of benjamins, well okay then. But beyond that, better to take that money and put it towards better pre / amplifier, DA or analogue source, speakers, interconnects etc.

Let's forward the Podcast to the thousands of sound technicians and engineers out there who produce music using mostly regular power cables.

@erik_squires Shorter version of this: Use shielded power cords.

How dare philistine!! This is a discussion by audiophiles. None of this KISS doctrine of yours may be entertained in such polite and erudite company ;-)

Darren at PS Audio is smart, no doubt. But as an electrical engineer myself, and a mechanical engineer also, Darren makes no sense.

If RF was really a problem in the 2-meter power cord, then everyone would have to turn off their phones when powering up their audio gear. The impedance of a 2-meter power cord to 60 Hz is nothing! I’ve measured the capacitance of my cords, also inductance. About 15 nanoFarads. 17 microHenries. Do the math!! Even pulling 30 amps, 120 vac, there isn’t enough impedance on my 10 AWG cord to make any difference at all!! And any RF is measured in femtowatts! 

Sorry, but Darren is smoking way too much Colorado weed, and overselling PS Audio’s premium power cable! He needs to just sit down, shut up, and stick to his circuit design tasks!

Paul McGowan makes the case for braided power cable. He too needs to sit down, chill out, and stick to selling his Octave Records and FR30 speakers.

Just a bunch of horse shite.

All of these battles between the believers and the naysayers are ridiculous.  Amazon permits free returns on the Pangea Audio AC 9SE MKII Signature Power Cable and probably other cables as well.  Buy one and try it in your system.  See if you can hear a difference or not.  Keep it or return it.  Easy.

Personally, I have gone from a cable skeptic to a believer, albeit with a careful attention to budget since cables are clearly one of the most overpriced audio components.  And the reason I have changed my mind is because I have heard the improvements that cables can make in my system.  Maybe it is all in my head but I have carefully done A/B tests on everything I have decided to keep.  And I understand all the tricks of confirmation bias and psychoacoustics so maybe it is all just in my head but I don't think so.

And I have had friends come over with a box of random interconnects and damn if you can't hear an audible difference between each one.

Does it make sense, no I'm not going to argue that.  And I certainly wouldn't argue that whatever differences I'm hearing will show up in Audio Science Reviews testing.  But being a pure objectivist without subjecting that belief to listening seems very irrational.  


I guess people that have systems 5-10 thousand total are screwed because they can’t spend the ridiculous amounts charged for ridiculous cables that people with blah blah years experience suggest. Perhaps one should listen to the majority then listen with their own ears and finally enjoy the music. I know first hand.., means nothing to anyone else’s ears. Lol

I guess people that have systems 5-10 thousand total are screwed because they can’t spend the ridiculous amounts charged for ridiculous cables that people with blah blah years experience suggest.

That is incorrect. They are not "screwed", if by screwed you mean that they are precluded from buying said cables. Because they can, can’t they?  Why do you say that they can't?  Makes no sense.

In an educated manner. Eyes wide open. My simple assumption, which may be incorrect, is that they can actually read.

Your audio location may suffer from an overdose of electrical interference noise, from wifi, GSM, babyphones or what have you, maybe ’Earth rays’. First off, these are all far outside the audio spectrum and are inaudible. Maybe a PC or laptop in the neighborhood could generate audible digital noise.

But have you seen the big and the small capacitors and maybe also coils in your amplifier’s power supply? Those are there to filter the 50/60 Hz ripple and any higher frequency noise away. They do such a good job at that (unless poorly designed, but I assume you have high-end equipment), that the tiny little extra inductance and / or capacitance that a 2m power cable can have is NOT going to help any. Also if your power cord inadvertently acts as an RF antenna ... the power supply filter will take it all away.

My personal adagium: if something costs more than twice the net worth of the components / materials used you know you’re being lifted.


"Shorter version of this:  Use shielded power cords."... Of known inductance and capacitance.

It's no use these guys telling us that capacitance and inductance are the reasons power cables sound different.  Two cables each of known capacitance and inductance will sound the same.  Buy those values you think are good for your system.

And what about the RF picked up by the 10 miles of power cabling between the power station and your home.  And the cabling in your home from the meter to the listening room wall socket.?

Even if there is an effect, the last 6 feet of cable will impart FAR less of it than the previous 10 miles, much of it at way higher voltage.

Ho hum

If power cables do make a difference then why don't expensive amplifiers come with the best power cords already included in the box? 

The manufacturer would have tested the best one for their product and added already. 

In my house of stereo with its own dedicated power feed and zero in home interference, expensive power cables have made no discernable difference in sound. On the other hand, expensive interconnect and speaker cables have made a very noticeable difference. Since many people state their power cables make a difference, my conclusion is that it likely depends on what kind of electrical feed and interferences you have. 

I recently bought the Pangea AC-14XL power cord for my CDT6000 Transport. (it arrives today) I have Transparent Audio power cables to my 300 watt tube monos. I also have (4) 20amp lines for my equipment. 1 for each amp and 1 for the Transport/DAC and 1 for whatever comes in the future.

I tried to listen to the f'n boring! I felt like I was listening to those not so funny Canadian comedians from the past ( Bob and ?) Obviously I am not an EE and never plan to be. I do, however listen to music and love great reproduction to my ears. I am probably too critical as I do not have $17000 speaker cables, etc. My system costs less tha $16000....but I did spend around $1500 on cables from beginning to end (excludes the dedicated install). I used to think cables could not be so important but as I upgraded I found they did help improve sound. Some big improvements...though I did not use crap cables back in the day ( ex. AudioQuest Ruby interconnects and Straightwire digital. I have other cables like Acoustic Zen and Kimber to go to for comparison.) I currently use Audio Art middle of the line throughout and find them pleasing. I also have 2 Adcom 555 high current SS amps. I think that amps need the power from the wall therefore the dedicated lines and cables. Got nothing else to add. Just stating cables in the system did improve sound. Maybe AC cables can help feed the beasts that feed the speakers (4 ohm load Maggie 3.7s) Still happy at home listening to the best system my pocket book could afford.


oh boy here we go….lol. 

Cables do make a difference and cheap poorly engineered cables can detract from a systems sound quality. 

What is lacking here is the actual testing / comparison before and after the luxuary power cable is used? Does the power get cleaner? I don’t think it is hard to do, right?😉 I believe the burden of proof is on whoever claiming the superiority of the cable.



I just listened to 20 minutes of the podcast and I think you need to be an engineer to understand what they are talking about.  They are obviously tube amp advocates.  I wonder what actually sounds better a tube amp or a solid state?  I know when I was listening to a pair of SALK Song 3 Encore's at the RMAF, Jim Salk demoed them through a pair of tube mono blocks.  They did sound warm.  There must be a reason why Jim chose tube amps to demo them.  My son is about to jump into this hobby and so far he thinks he might go with a tube amp.  I am not sure what to tell him because I thought tube amps were designed with old fashioned electronics.  It is never too late to change my system.

When we know the power of acoustic on the system/room, we know that cable may may make a difference but a minute one compared to acoustic...

Then prioritize...

But for most people buying and plugging is the substance of this hobby not experimenting with acoustic and a working ears/brain...


Factual..This topic is repetitive and boring. Take it to a vote the I assume, guess, believe, cables make a difference line there, The black is black, white is white, on or off, line is here.
We all know which is the longer line…that is the fact.
Spend if you will, believe or not…

Be happy, move on !


Maybe my post is the confrontational comments and hostile language? It was not meant that I'll say it this way. I am sure the pod casters know what they talk about. As I am so EE impaired, I was bored. It would be like carrying on a conversation with the fictional character Dr Sheldon Cooper about theoretical physics. I would be bored even listening because I could not participate without sounding slightly dumber than "dumb and dumber". Cables have made a difference in my listening experience. I prepared my experience from breaker to receptacle. I upgraded cables. It was an improvement from a-z. So sorry if I offended anyone.

Naysayers seem to have some kind of savior complex in their need to try to save cable-believers from buying supposedly overpriced cables.  But nobody is twisting their arm, and as already pointed out, there is a large number of companies that offer 30-day free trials.  Arrange to have 3 or 4 in your price bracket in house at the same time, and let the testing begin.  If you hear something significant, or think you hear something (which amounts to the same thing), then buy away, if not, don't.  It's as simple as that. If possible during testing I'd recommend people ensure that it's repeatable--i.e. compare a couple of cables on different days and see if you get the same results.  As always, you need to be honest with yourself as to what you're hearing, rather than what you want to hear.

@vanson1 - probably because they know that most people buying expensive gear will have their own preferences for cables and may already have some very expensive cables already, so why add a lot more money to the price just to include expensive cables that might not even get used? That's why these companies all include those black generic cords and cables so if you don't have something already, you can at least get it up and running till it's replaced with something better.

When putting in place the audio system, hearing aminute difference that seems bigger of what it is a REGULAR experience in the journey...

What matter is a set of listening experiments in mechanical, electrical and the acoustical working dimensions of the audio system..

Forget for a time or forever buying and plugging upgrading piece of gear...Especially cables...

Buy one basic good system and think... And study...Create a SET of possible listening experiments...

You will buy good cables if you can afford them or basic one, nevermind , but you will never throw your money for minute difference gain with costlier cable...

Acoustic is key not cable...But difference in cable is an EVIDENCE for my ears.... It is aminute one though... I will never pay for very costly cable passed a few hundred bucks..

By the way i modify all my cables at low cost with my own devices...

Why buying when you can do it?

@noske @larsman @vanson1 In respect to using less expensive power cords, one thing that Darren and Duncan have said on their podcast is that PS Audio supplies a decent but not particularly expensive power cord for their components. This stock power cord was chosen because it provided a balanced performance for multiple aspects of sound quality. Though improvements can clearly be had over the stock power cord, they also said that it can take a bit of money to get a power cord that is clearly better in all respects. Apparently at a more moderate price point, power cords can improve specific aspects of sound quality but at the detriment to other aspects.

My takeaway from that comment was that listening to a power cord is vital & that a more expensive power cord is not necessarily better than one that is less expensive. What parts of sound quality someone is seeking to improve would be a important consideration in deciding whether to buy a more expensive power cord at all and also in determining which power cord to choose.

@larsman I completely agree with manufacturers not wanting to spend excessive amounts of money on power cords. From a business perspective, this bumps up the "base" cost of their components. I agree also that people who are into cables might want to use their preferred cables. Another activity that I spend money on is bikes. Saddles (seats) on even fairly expensive bikes are often throw-away items since everyone has a different preference for what saddles they prefer.

I do wonder why audio equipment manufacturers don't suggest power cords that work well for their equipment (or perhaps several power cords from different brands depending on the sonic characteristics that a buyer might be looking to optimize). Perhaps because they are too busy designing equipment to be testing power cables which are not part of their core technical expertise?

I like black generic power cables. The only reason I will not use the stock cable is if it's to short or long that's when I bring up the browser and order a shorter or longer black generic power cable.  

@calvinandhobbes - perhaps the reason why they don't recommend power cables is that they may recommend something and the customer doesn't like it, and then you've got problems. What may work fine for one person may not not work well with another's, plus they'd get deluged by cable makers all wanting their own cables to be on the recommended list, so they figure let the customers do their own research and purchase of cables, which make sense to me...