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.



"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.