Do power supply units/cables make a difference in sound quality?

My system is plugged in via a heavy duty power strip into a wall socket.  (Horrors!). I have read many posts from folks who have invested $$$ in power supply units and cables.  Before I take a deep dive into that, I'd like to hear from folks pro or con on this subject.  My system consists of Magneplanar MG3rs, Nelson Pass Threshold 400 amp, Conrad Johnson recent premier preamp, Oracle TT with Koetsu Black, Bluos Node streamer, Classe Audio CDP-102 CD Player.  I am quite happy with the sound from all sources.  So am I in for another four figure expense with power supply?  I appreciate the experience of this forum's members.


You have a very fine system! Don't fall for the malarkey that special power cables and AC conditioners are a necessary part of a quality system. A system's sound starts with the power supply of the various components. NOT with the wire from the AC outlets! RF noise from the AC outlets is a non-issue for any competently designed power supply. I always leave the components' captive power cords alone. I don't use power conditioners/AC regenerators. These are just to get the gullible to spend more money! 

Those that claim to hear a "sound" from different power cords are in the throes of confirmation bias. Naturally the shiny new toy always provides more enjoyment - until the thrill wears off!

Ever since Noel Lee brought forth his Monster Cable company around 1976 the audio scene has been plagued by hyperbolic ad copy extolling the virtues and superiority of Cable A over Cable B. Before that audiophiles used zip cord and Radio Shack gray Switchcraft interconnects - and nobody complained! Suddenly manufacturers saw great profits to be made selling "audiophile grade" wire to the masses. All the claims of the superiority  of one cable over another have ZERO bases in scientific evidence. "My golden ears tell me it is so" is the common refrain! Like the eyes being fooled by optical illusions human ears and hearing are easily fooled!

I always protect my expensive equipment. I use maintainers with circuit breakers and of course surge suppression. The quality of the AC source is as important as cleaning the dust off a stylus.

Power cables and quality cabling are as important as quality equipment.

A few of my buddies use Threshold and I use to. You better use a good PC. It has nothing to do with looks is does have everything to do with performance.

No it doesn’t cost a fortune for very high quality cabling. I can purchase an entire set of cables for 500.00. I can make them for about 300.00.

Enjoy your upgrade and enjoy the new sound. Be patient, it pays. Be kind to your cables. Handle cables with great care and protect the terminal ends against static discharge after they are conditioned.. Everything matters..

+1 @helmholtzsoul 

A system's sound starts with the power supply of the various components. NOT with the wire from the AC outlets! RF noise from the AC outlets is a non-issue for any competently designed power supply.

A system's sound starts with the power supply at the point of origin, the service panel. A dedicated AC line is the best way to insure that appliances and electrical devices in the home are on separate circuits and don't add noise to the audio system. A quality receptacle and power cord should be considered part of the audio system. The use of a power conditioner is usually a benefit, but each owner can make this decision. I use balanced power conditioning with surge protection and the improvement in SQ can easily be heard. The power supply on components plays an important part by regulating voltage but can only do so much. RFI/EMI filters will further lower the noise-floor.

Those who say they don't hear a difference between a treated AC line (as stated above) may not have a system that is revealing enough to appreciate the benefits.





I don't think the quality of the electricity is as important as the quantity.  The PSU in your amp promptly rectifies it and regulates it so the electricity coming out of the wall it pretty much adequate in quality.  60Hz and approximately 120V.  A little noise that gets cleaned up almost totally by the PSU.

The quantity is more important.  You need a ready supply of quick current for your amp to deal with spikes or quick demands. This is required to make your amp quick and responsive, especially in the bass area.  

I think people often focus too much on quality and too little on quantity.  A generic 10awg cable will get you 99% of the way there by ensuring there is a ready supply of current.  Cleaning up the quality of the electricity may get you 1% since some tiny percentage of the "noise" in your electrical line may get through the PSU. But this is very tiny. 

Power strips and conditioners that limit current can do more harm than good.


Carlsbad:  Your comments coincide with my beliefs.  I somehow could not wrap my head around how the quality of sound would be affected by the electric connection cables assuming they were adequate for the needed flow and fit will with no interferences.  My house current has always been adequate for the loads of my system.  My main concern is surge protection and I have accounted for that.  Looking at four figure prices for power regulators and cables had me puzzled as to how much they would affect the sound from my system.  Thank you.



@baumwoll - having spent many years investigating cables, I have had first hand experience of how different things can positively impact the sound we get to enjoy from our systems

I have has success implementing cables on mini-systems costing as little as $200, up to pretty good systems in excess of $70k - other members have much more expensive systems and have observed improvements also

Unfortunately the cable companies like to spin their jargon as to why their cables are the best.

But the answer is pretty simple - a good cable will use...

  1. excellent quality wire - copper or silver
    • There are varying grades of copper in used, the best being UP-OCC copper
    • There are varying grades of silver used, with UP-OCC Silver currently being the best
    • What is the difference? - Conductivity
      • beryllium copper, teryllium copper, Bronze or Brass
        • are all copper alloys
        • their Conductivty is 70% or lower
      • Pure Anealed copper is rated at 100% and is the Benchmark for Conductivity
      • OFC copper is around 101%
      • UP-OCC copper is 102% -103%
      • Silver is 106%
      • UP-OCC silver is 107%
    • What is the benefit of using a high conductive metal ?
      • better details and improved clarity
      • better/faster dynamic performance
      • better/faster transient processing response
  2. good quality insulation
    • lowers cable related noise issues - so it lowers the noise floor of a cable
    • The Dielectric Constant (Dk) The ratio of the permittivity of a cable
      • is the metric used to indicate the electrical activity of the insulation
      • As the signal changes polarity in an AC sifgnal it charges the insulation in one direction
      • and then recharges it in the opposite direction as the polarity changes
      • this flip-flopping injects noise into the metal wire
      • using insulations with a low Dk improves clarity, details and imaging
        • PVC has a Dk of 4 (ish)
        • Teflon is 2.2
        • Foamed Teflon is 1.45
        • Cotton or Silk is 1.3
        • Air is 1.1 Vacuum is 1.0
  3. built using a good noise cancelling cable geometry
    • Cable geometry is how the individual conductors are situated with respect to each other.
    • When you have two wires side be side in close proximity, as with many cables in use, you get distortions induced from one wire into the wire next to it
    • This is noise and impacts overall cable performance
    • Some examples of cable Geometry are
      • twisted pair
      • braided (e.g. Kimber Kable products)
      • Helix Spiral designs (e.g. Anticables)
      • Ribbon - Like Nordost speaker cables
  4. use great quality connectors
    • many connectors use brass or some copper alloy, but as identifed above, the low conductivity metals impede performance
    • Also, in the case of interconnects and speaker cables, the mass of the connector also impedes signal trasmisson
      • well enginnered Low Mass, high conductivity connectors provide significantly better performance
    • For Power connectors, pure copper or silver plated copper provides better performance

As with everything in this hobby there are improvements that can be achieved with "refinements" to the above design points and those refinements will cost a lot more.

RE:  the "Power supply" to the system

  • most power supplies to the house are stable, but some people do experience noise related issues often from commercial builds that are close by, and for those, a good power conditoiner or power regenerator is often reqired
  • Othrewise, if the power supply to your house is relatively clean then simply having a good power cable to each component will improve sound quality, Why?
    • this is how it was explained to me by a very knowledgeable person with a wealth of Electrical Engineering experience
      • At each connection point in the "power supply line" i.e. at each breaker, outlet and plug - the transfer of electrical energy is only depedant on the quality of that connction and the quality of any wire used to bridge from one connection point to the next
      • This is why a good power cable will provide improvements in performance
  • A dedicated line from the breaker panel to your system provides noticeable benefits
  • Quality outlets, like Hospital grade MRI outlets from companies like Pass and Seymour, will grip the plugs more tightly and provide better power transmission

RE:  the power supliies inside components...

  • Power amps tend to have very large transformers and banks of capacitors (i.e. compared to source components), which are designed to supply enough power, especially when large transient signals are encountered
    • But even the very best amps can also benefit from having a very good power cable
    • But for the best amps you will need an exceptionally good power cable in order to achieve any noticeable benefit
  • Source components, especially in the more budget oriented designs, tend to have a less capable power supply, so having a good power cable will provide a more noticeable benefit.
  • Wal-Wart power supplies are perhaps the worst - I avoid them or replace them

The cable companies I typically recommend include

  • Zavfino
  • In-Akustik
  • Hijiri

There are a few others, but these provide good and noticeable Bang-for-buck

Zavfino is a great place to start and their product line caters to many budgets and their products actually perform.

As you may have observed in this thread, there are many opinions out there.

Some believe in the benefits of cables and other do not

So use the Audogon search feature to aquire knowledge from postings from other members pertaining to cables.

Apologies for the long post, but this subject gets complicaed very fast


Hope it helps - Steve


@baumwoll  Threshold amps are some of the greatest amps ever built. I personally use a Threshold Stasis 350e in one of my systems and I recently replaced the four rail fuses.

I could not believe how great it sounds now, it was great before but now incredible and I haven't changed the main fuse yet!

I used HIFI Tuning gold plated silver fuses, only about $40-$50 each, but an incredible upgrade.

There's a lot of negativity about cables here so just try the fuses, it's a very small investment.

Power amps always directly plugged into the wall.

Thanks steve for your input...were all the benefactors of your experience 👍


Steve, Thank you for taking the time to post such an informative description on the subject of cables.  I buy into the contribution of high quality connecting cables between components up to a point of cost/benefit.  The value of a power supply unit costing 4 figures is questionable for me, given the stability and lack of interfering noise on my rural electric supply.  I am really curious about Lordmelton's suggestion to try HiFi Tuning gold plated silver fuses, I assume on my Threshold amp.  I wil explore that.  Thanks all.


Lots of smart folks offering opinions. I'm in the same throes debating whether to add something other than the Furman ELITE15 PF i Linear Filtering AC Power Conditioner that I own. Before I dive into a more expensive component, I'm having a dedicated line installed from my main panel to my stereo system. I also purchased a "Silver Cryo Receptacle" so the cost will be a few hundred dollars. I've talked with a few audiophiles that confirm, it is an inexpensive step to do before shelling out thousands for a power plant, conditioner, etc. that may/may not help. 

“I am quite happy with the sound from all sources”

^Your answer^

I wouldn’t buy the cables. 

As you can see, some say yes and some say no. The only way you can come to any conclusion is to try it yourself. Personally I found that some power conditioners can adversely effect SQ and that spending big bucks on power cable is a waste of money. There are many cables around $100 that will do the job admirably.

Indeed. That is my conclusion.  I will invest in a new cartridge for my turntable.  I think the Koetsu has worn down.  That will make a hearable difference playing records. Thanks all who took the time and trouble to answer my question.

@baumwoll For nearly 25+ years, I never felt the need to change power cords, fuses, interconnects, add power conditioners to "improve" the sound from my audio system. @jasonbourne52 pretty much summarized the technical reasons behind why such changes don't make a difference.


Electronic components have built-in power supplies that controls the DC voltage/current ultimately responsible for driving electronic components in the audio path. Some components have multiple power supplies with well regulated for fluctuations in the AC supply. This is not rocket science anymore, but well established design concepts of audio gear.  Adding power conditioners, changing power cords/fuses won't make an iota of a difference. Same goes with cables and interconnect where most commercially available at "reasonable prices" can get the job done. I have Kimber 8TC as speaker cables. All the components are plugged into surge protectors with power amp having its very own. So don't fall for marketing gimmicks and save your money

pwerahera I have the same view as you express in your post.  I wanted to see if anyone on this forum could give me convincing argument to change my mind.  The cost of these power control units and cables is far to high for the benefit the purport to deliver.  Good quality surge protectors and a stable source of AC is all I need on that end.

@baumwoll Vast majority have never taken classes in electrical engineering that include Electrical Circuit Theory, Electrical Measurements, or Wiring Diagrams classes. Few years ago, one of the biomedical engineering faculty members told me, there is no need to teach sophomores Thevenin's and Norton's theorems because they are never going to need it. I can see in near future use of geometry, trigonometry, algebra getting the same treatment.  It is all now in the computer. You give the input parameters and computer gives you "what it thinks you want." But they lack the knowledge how to get there. So there you have it. For an old hack like me who spent hours and hours learning and then teaching these subjects face an uphill task convincing the masses what is true and what is not.


Glad you found some of us still around. One of my teachers/mentors passed away few years ago, Dr. Aram Budak who wrote several text books in EE. He would have gotten a good chuckle if he saw some of these posts describing audible differences in cables, fuses, etc. He retired to Grand Tetons, WY of all places. Until his very last breath, he could get a great view of the Tetons from his living room. He loved music and his favorite was Richard Strauss. His final request to the family was to play Death and Transfiguration at his funeral.

One of the funniest posts I've read recently on A'gon was from someone extolling the virtues of his new power cord that cost more than the his top of the line (read: very expensive) integrated amplifier.


Aggree 100%, how many times does this total BS and nonsense have to come up. Engineering and science aside, A/B placebo affect sucking people in, stupidity denial spending more money on wires than equipment. Makes me think of a comic sketch of a group of challenged Christmas carollers belting out do you hear what I hear….Who care’s ? Most don’t believe in magic beans, a flat earth, or life after death again….Who care’s ? If you can’t prove it but hear it..enjoy it. Ya have to ya paid for it, don’t want that used market beating.


I live in Europe, we have 230V outlets. I’m sorry for all you guys on 110V that you only have half the sound.

We've been through all this dozens of times in the last year.

Clearthinker has his head screwed on properly.

I'm not with the dreamers who think they can hear differences in passive well designed mains cable and even fuses but they will never agree with me nor submit to blind tests so it can be proved they are not simply experiencing confirmation bias.  Until they do, this will run and run, wasting everyone's time.  They should shut up.

But system interconnects can make small differences and active conditioners can certainly clean away unwanted noise on the line if your power supply suffers from that.

i think you're lying))) - you have good components and you probably use good cables...

A good cable is better than a bad one

Seriously?  Did the OP bother to search previous threads before resurrecting this old horse of a topic?

I think the OP wanted confirmation that he wouldn't hear a difference when adding power supply treatment.

His only interaction was with fellow non-believers. This thread was a waste of time.

Oh forgive me for being new to this forum and asking a question some of you are tired of answering.  Fortunately, I did get useful answers which led me to conclude my money is better spent on getting a new cartridge than it is with power supply equipment.  I am grateful to those who took the time and effort to answer my question, pro or con.  The thread was far from a waste of time to me, but no one forces you to read it.  Anyone with 4,893 posts must be very knowledgable indeed.

This place is often at least as funny as the best of Saturday Night Live.  Over and out.

Post removed 

Some folks offer trial periods for in home listening. Try that as your system is of high quality. Nothing to lose but some shipping costs.. But replace your cartridge first. 

Williewonka - Steve

Very nice write up. Great information and explanation.

Thank you


@baumwoll Trust your own ears, no one else's. Ignore the naysayers.

You've probably got a flat screen TV, change the power cable to a NEO by Oyaide D+ only about $50.00, if that doesn't prove anything nothing will.

My two cents, both as a designer and a listener:


AC cables - no difference unless there is a serious problem with one.


Line (noise) filters, from LC filters to isolation transformers to regenerators do in fact have an effect.  Blocking noise from digital components that may be part of your system is also valuable - meaning put the computer/server/streamer on the DIRTY side....


yes a good internal power supply will minimize much of this, but ground noise in particular does come through, albeit at a very low level.


I also ensure that the wiring is up to snuff ( i have a 20A home run from my service panel) and the outlets are good quality ( i use the highest grade that Home Depot sells). A quick look at the construction shows how chintzy the cheap outlets are.

A cheapish experiment might be just losing the outlet strip and installing a quad on the wall.  Surge protected outlet strips in my system did not help, and outlets are relatively cheap to install.

quick comment on some above.  Surge suppression and noise filtering are (almost) totally different beasts. A surge suppressor will have essentially zero sonic impact.  A properly designed filter however, will take noise well above 60 Hz out of the AC signal.

Don't confuse the two.