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

Gene mentioned the Romex behind the wall in the video. I don’t see how that come into play. The Romex and the miles of cables before the wall outlet do not matter. There is no physical flow of matter from one end to the other end of the cable. The electrons vibrates at 60 Hz from the same point. Take care of this vibration and you take care of the problem. After all, our energies are derived from these vibrations.

I ditched my power cords, and while I was at it, tossed my VAC tube amp, my Focal Sopras and my Project turntable out of the window. Instead, I just hire the actual singers now. I found them to be a bit analog for my tastes. I keep trying to reposition them in the room. Room positioning is under rated. Some singers don’t like to move, while others don’t stop moving. Dealing with the spittle is now a problem, as is room size. They don’t have a setting for that. And they don’t like to be told to stop in the middle of a song when I change my mind. I think I might have to get rid of the actual singers and go back to a simple set up of normal gear, normal speakers and normal power cords. I may have taken this too far. 

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).

If there was a reduction of noise with no Musial signal, then it almost seems like we could measure the RMS AC noise at the speakers and see it then?