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

Showing 1 response by clearthinker

@erik_squires 

"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