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

Folks, merely twisting wires won't necessarily do it any more than laying out a conductor, a dialectic, and a conductor makes a 20uf capacitor. A power cable is a capacitive, inductive device, and it can filter some frequencies, but not necessarily the ones you are having issues with. I have been in this hobby for over 40 years now. I never bought into the power being a problem until it was for me. I bought a Yggdrasil DAC, and the highs were killing me. People recommended power conditioning devices, but I blew it off until I had exhausted all other remedies. I finally broke down and bought an isolation transformer, problem solved. Likely the right power cable would also have fixed the problem, but the used isolation transformer was about $100, and power cables are all over the map, and who knows how many I'd have had to go through in order to get lucky? So, when someone says that power cables matter, I figure that they got lucky.

@shooter41 I could not agree more and yes I have purchased some of those mega buck power cords from companies with 60 day return privileges and returned them all. They made little or no difference from the $300 to $600 cables I have purchased.

Now those $600.00 cables did make a difference over stock and yeas my listening room is treated for acoustics.

I believe in tweaks and I have done some that work and others that are pure poppycock and have been sent back.

 

I personally feel like the uber-expensive cables are pretty foolish and exist only for those with more money than sense,

I don’t need an engineer to tell me what I hear. From the outlet forward, clean power is the most important part of any system. A combination of quality power cables and power conditioning is critical. Period. 
 

 

From an electrical engineer, not an electrician, I can find a technical path on why it is true that power cables make a difference.  We as EEs need to comprehend the reactance of the cable - which is really a passive circuit.  There is reactance to ground, between the neutral and hot, . . . and to the outside world. Need to model the inductance and capacitances to all adjacent paths; this is a spice model that can be analyzed.  That mathematical model must include frequency domains that are beyond 60 Hz, and transient currents.  While I will never take the time to build that model and measure it, I do believe its a fact.  We must get beyond the adultescent thinking that power cables only carry power.  In the real world of audio, they are a component that do contribute to the end result.       

As someone that has a graduate degree in Electrical Engineering, there is no doubt cables can make a difference.. But for me it is always a price vs performance issue. If you have the means,  then go for them $10K power cables / power regenerators. It will improve your sound quality. But I would rather have $9,950 in the bank and spend $50 max for power cables.