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:
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:
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.

calvinandhobbes

Cost, I think, is the main factor for not providing a better power cord. The other reason could be that the outcome is system dependent with the characteristics of the speakers playing a major role.

My hypothesis is: difficult to drive speakers are more sensitive to the quality of the PC and vice versa. Opinion?

My hypothesis is: difficult to drive speakers are more sensitive to the quality of the PC and vice versa. Opinion?

If there was a difference, then it should be happening when there is more need to have greater current flowing in. So ^your hypothesis^ makes sense.

 

if the electrical signal coming out of the amp was changed (like playing the same content and comparing the captured signals), then we would know that there is a real difference.
How hard would that be to do?

Electrical engineering theory in the strict sense makes sense regarding this discussion, and when looking at high quality power supplies, one can see that any RF noise coming from the wall to the power supply should be easily shunted away.  That said, there are obviously some subjective observations that have been made by MANY when swapping out power cords noting sonic improvements.  I for one am one of them...  Being skeptical, I thought that power cords wouldn't make a hill of beans difference, however I tried power cords with neodymium magnets on both ends by the plugs on my power-amp (I don't know what other mechanisms in the power cords were at play).  Even before I dropped the needle on the album, I noticed a slightly blacker background and when playing music, I did notice a slight improvement in micro-detail (m I assume due to the lower noise-floor).  So, to make sure I wasn't "hearing" things, I did a blind swap-out of the two power cords with my audiophile buddy doing the listening.  He too heard the same changes with the experimental power cords.  So, there's really something to this power cord thing.  The biggest issue for me is setting my personal "Law of diminishing-returns" on stereo equipment and especially cabling of ANY kind !  The discretionary $$$ coupled with some semblance of common-sense seems to prevail with me.  

One thing I've adopted regarding measurements...  If it measures well and sounds good, it's good...  If it measures well but sounds bad, it's bad...  If it measures bad but sounds good, perhaps you're measuring the wrong things !  

Acoustic and psycho-acoustic can explain and describe sound perception not electronical engineering alone and especially not only measuring tool compared to human ears when it is a question of TIMBRE recognition for example...

Simple but too complex to understand for most...

Then imagine geopolitic historical understanding ? Sorry but it is so.... It is impossible to discuss these matter here anyway, be it geopolitic or psycho-acoustic Audio threads are about "tastes" and price tags😁😊

Like children in a yard: good and bad people, subjectivist and objectivist... Rightwing/leftwing, ETC...

The unpalatable truth is most people’s hearing is very lacking when it comes to hearing notes and tones and timbre.

How many have actually played a musical instrument or been close enough to one to adsorb the sonic expressions and delicacies.

Sing or hear a real human voice up close.

I believe this is the reason why lots of audiophiles go for high priced equipment recommended online or in magazines to show that they’re audiophiles.