A pricey power cord

[kb3ouk]

i think a lot of this is beginning to make sense, especially about the power cords. so what you are saying, is the power cord is picking up RFI and all the crap that comes out of the power supplies then feeding it through the power supply?

oh, and one more question from earlier in this topic:

Was on 3.875 recently and heard the diddlies there. This was followed by the story of Tron trying to confuse it off the air. 

how exactly was he trying to confuse it off the air?

shelby

[WBear2GCR]

In other words, let’s just throw science out the window and take the word of a few audio enlightened individuals, most of which are hawking some product. Elmer Gantry anyone?

I never said anything like that. Did I?

Science should not be disregarded.
Electrical Engineering should not be disregarded.
Neither should perception, as in hearing, be disregarded.

I did say to let us put aside the issues of price and claims that may not be based in reality, and discuss what is the basis and reason that there are people out there apparently being successful while selling overpriced products based on questionable claims.

Ok?

                 _-_-bear

[WBear2GCR]

Bear, I'd like to know what other esoteric components besides the power cord that you consider important to good sound reproduction that most of us would ignore?

Eric

Eric, you can take almost any component that is used and substitute in a higher performing one and IF you do this across the board for a given piece of gear end up with an audible difference in sound UNLESS the rest of what is in your signal chain masks the change. Why would masking take place? It happens when there is sufficient distortion of one sort or another so as to make the reduction of distortion you have just achieved inaudible.

That's a simple way to explain it.

Examples include changing out carbon comps for metal films, using teflon or polypropylene caps for mylar or (worse still) electrolytic caps, etc...

These are very basic examples. Quite audible.

I've said these things and given suggestions as to how to possibly hear these  things for yourself, in the past on this forum.

For most people this doesn't mater at all. I don't agonize over any of it in my ham gear, for example. A non-issue.

It's more like a photographer making a very large size print and being very very careful to get the focus right across the print, getting the exposure and developing just right, the chemistry, all the details. Maybe discarding test prints until it is just right.

Then you guys come in and say, hey I get my disposable camera's prints from the 1 hour place and they are just fine! How could any of that make any difference? Hope the analogy makes sense.

Again, spend some time on http://www.diyaudio.com and look at the circuit discussions in the Solid State section, including the discussions on the use of particular resistors and transistors WRT the "sound". Take a look at two threads in particular: F5 (amplifier), and John Curl's Blowtorch. You will see posts ranging from newbies to world class (credentials beyond reproach).  The F5 is a VERY simple amp... that is why it is illuminating to see what is being said and found. These people are not delusional, and for the most part work separately and their questions and issues come up independently, in other words they are truthful and honest.

Take a look.

You may find it interesting.

  _-_- bear

PS. if you look at the speaker section you will see a huge amount of independent work being done on things like horn design, that includes FEM analysis, and tons of simulations and actual testing using the very latest technologies... really parsing the subtleties.

[WBear2GCR]

i think a lot of this is beginning to make sense, especially about the power cords. so what you are saying, is the power cord is picking up RFI and all the crap that comes out of the power supplies then feeding it through the power supply?

shelby

That is one possible explanation. GFZ is saying that this should NOT be possible if the gear is "properly" designed. He may be correct that one could build and design so that changes in the power cord make no difference.

But even if one could do this - and it is not clear to me that you can - that only eliminates ONE single source of variability in any given system.

In fact this is the goal of many in the field, to make equipment that is invariant to external factors (including cabling) and also does not  change due to internal factors, including parts type and selection, etc... this is on top of or beside the underlying issue of circuit topology and design.

                       _-_-bear

[k4kyv]

i think a lot of this is beginning to make sense, especially about the power cords. so what you are saying, is the power cord is picking up RFI and all the crap that comes out of the power supplies then feeding it through the power supply?

How does some kind of a special power cord keep all the crap the a.c. house wiring on the other side of the wall-board has already picked up, from getting into the audio equipment? Remember, the power cord is only the last six feet. The noise and hash that comes out of the power supply would feed into the equipment circuitry via the + and − leads; the power cord attached to the opposite end of the power supply wouldn't have anything to do with it. Just as in the case of radio reception, the best transmission line in the world, precisely balanced and carefully wired to eliminate all common-mode current, still won't help with a signal already obliterated by line noise or touch-lamp and plasma TV garbage.

Instead of purchasing a $1000 power cord and "hospital grade" mains outlet, invest in an isolation transformer with built-in Faraday shield between primary and secondary to eliminate noise and RFI. Place shielding round the power cord if you think it is necessary, rather than throwing away money for special oxygen-free broken-in copper conductors.  For best results, go one step further and use a Faraday-shielded isolation transformer that has a precise mid-tap on the secondary winding.  Ground the mid-tap and run the equipment off an a.c. source balanced in the same manner as a balanced 500/600 audio line. Make sure the amplifier and other equipment has adequately by-passed and filtered a.c. power leads coming into the chassis, using proper grounding techniques to keep the crap out of interior of the chassis and to avoid "pin 1" faults. The chassis base should be fully enclosed with an rf-tight bottom plate.  IOW, use standard, long-established well-known quality construction practices and engineering techniques, and spend your money on top-end professional grade components, instead of throwing it away on phoolishness.

A good, Faraday-shielded isolation transformer with mid-tapped 115-volt secondary would likely cost substantially less than one of those "cable breaker-inners" you see advertised on the internet.

Regardless, the quality of the sound you hear out of a system can be no better than the program source - vinyl, CD, MiniDisc, FM radio (including HD), internet streaming, etc., unless you do all your own home recording.  I doubt that the studios that produced the recordings concerned themselves with special high end, oxygen-free, broken-in power cords and their ilk, or anything else beyond standard top-of-the line hardware that carries no claims of "magic". Recording studio engineers probably get as much of a chuckle out of reading audiophoolery stuff and viewing those web sites as the rest of us do.

[Steve - K4HX]

You immediately discount double-blind tests because they don't tell the story you wish to tell. That's throwing out science my friend and to say otherwise is fallacious.

In other words, let’s just throw science out the window and take the word of a few audio enlightened individuals, most of which are hawking some product. Elmer Gantry anyone?

I never said anything like that. Did I?

Science should not be disregarded.
Electrical Engineering should not be disregarded.
Neither should perception, as in hearing, be disregarded.

I did say to let us put aside the issues of price and claims that may not be based in reality, and discuss what is the basis and reason that there are people out there apparently being successful while selling overpriced products based on questionable claims.

Ok?

                 _-_-bear

[Steve - K4HX]

A good, Faraday-shielded isolation transformer with mid-tapped 115-volt secondary would likely cost substantially less than one of those "cable breaker-inners" you see advertised on the internet.

But only if it was wound with oxygen-free magic copper. Otherwise it would defile the signal even further.

This phoolery is a vicious wheel that only sucks you in further, ever in search of the holy grail of sound. It is never attainable since new "problems" will be dreamed up. So the money continues  to flow to those making up new problems. It's really quite a clever scam.

[kb3ouk]

assuming that the power going in was clean as could be, and the the piece of equipment was the crap maker, then i could see how it MIGHT be possible for the cord going in to pick up some of the crap from the device and feed it back into the power supply. that power supply was designed to filter 60 hz ac, not whatever RFI that it's own self may be making. so wouldn't that basically just pass on through and be riding along on the DC that should be coming out of the supply. and i wouldn't go out and spend more than $20 on a power cord, if i wanted to have a shielded power cable i'd simply take two pieces of some small coax, like RG-174, and use the center conductor of one for the hot and the other cable's center conductor for the neutral, then tie the braids together and use that as the ground. and shielding everything isn't necessarily gonna take care of RFI if the way the insides of the amp are just slapped together with no thought to the layout at all. i have an old zenith tube am/fm radio that i can set right next to my rigs and be running 200 watts out and no interference to the radio at all. there's no shielding at all: plastic case, and the chassis is open underneath. i had another radio, i forget whether it was solid state or tube, but i know it was not very well built compared to the zenith, and that thing picked up RFI no matter where it was.

[WBear2GCR]

i think a lot of this is beginning to make sense, especially about the power cords. so what you are saying, is the power cord is picking up RFI and all the crap that comes out of the power supplies then feeding it through the power supply?

How does some kind of a special power cord keep all the crap the a.c. house wiring on the other side of the wall-board has already picked up, from getting into the audio equipment? Remember, the power cord is only the last six feet. The noise and hash that comes out of the power supply would feed into the equipment circuitry via the + and − leads; the power cord attached to the opposite end of the power supply wouldn't have anything to do with it. Just as in the case of radio reception, the best transmission line in the world, precisely balanced and carefully wired to eliminate all common-mode current, still won't help with a signal already obliterated by line noise or touch-lamp and plasma TV garbage.

Reasonable question. IF this is the mechanism, of course. Some of these "better" power cords are somewhat capacitive and may be able to shunt noise to ground. That would be HF noise in the main... another "theory' that has been floated is that the power cord acts like a tuning stub sitting on the unit... I am not sure I subscribe to that.

Instead of purchasing a $1000 power cord and "hospital grade" mains outlet, invest in an isolation transformer with built-in Faraday shield between primary and secondary to eliminate noise and RFI. Place shielding round the power cord if you think it is necessary, rather than throwing away money for special oxygen-free broken-in copper conductors.

Don, this is done all the time.

People go one step farther with units that in essence "remanufacture" the AC after filtering, converting to DC and back to AC.

For best results, go one step further and use a Faraday-shielded isolation transformer that has a precise mid-tap on the secondary winding.  Ground the mid-tap and run the equipment off an a.c. source balanced in the same manner as a balanced 500/600 audio line.

I am sure you will be surprised to find that this too is commonly done.

Make sure the amplifier and other equipment has adequately by-passed and filtered a.c. power leads coming into the chassis, using proper grounding techniques to keep the crap out of interior of the chassis and to avoid "pin 1" faults. The chassis base should be fully enclosed with an rf-tight bottom plate.  IOW, use standard, long-established well-known quality construction practices and engineering techniques, and spend your money on top-end professional grade components, instead of throwing it away on phoolishness.

Of course. As I said disregard the expense of "voodoo" products and let's talk about what is behind the fact that people can sell them - there is a reason, even if the products you call "phoolery" are bogus. Ignore the bogus ones.

A good, Faraday-shielded isolation transformer with mid-tapped 115-volt secondary would likely cost substantially less than one of those "cable breaker-inners" you see advertised on the internet.

Well, the price depends... but the break-in boxes are not for AC power cords. So that part is not relevant.

Regardless, the quality of the sound you hear out of a system can be no better than the program source - vinyl, CD, MiniDisc, FM radio (including HD), internet streaming, etc., unless you do all your own home recording.  I doubt that the studios that produced the recordings concerned themselves with special high end, oxygen-free, broken-in power cords and their ilk, or anything else beyond standard top-of-the line hardware that carries no claims of "magic".

Depends on the "studio" Don.
You should read up, before speculating.
In point of fact you are more wrong than right about this.

Fwiw, there is one company that supplies downloads of high bit depth, high sample rate recordings now...

 

Recording studio engineers probably get as much of a chuckle out of reading audiophoolery stuff and viewing those web sites as the rest of us do.

Don, don't speculate about what others may or may not think. Ok?

Now, after doing all the things you suggested above, what would you do or say if YOU were listening and someone came in and changed ONLY the AC power cords and YOU heard the sound change? Of course you can claim that you wouldn't hear it. But what if you did? Then what?

                           _-_-bear

[WBear2GCR]

You immediately discount double-blind tests because they don't tell the story you wish to tell. That's throwing out science my friend and to say otherwise is fallacious.

No I do not.

I have read quite of few of them, the original papers, and I question their premises, their conclusions and their rigor.

You are free to think that just because a test was made that it is valid. These "tests" claim validity base upon a statistical finding. All well and good, but again there is NO  BASIS WHATSOEVER shown that the tests are capable of detecting or discerning the thing that is alleged to be tested for. Many of these tests have results that can not be GENERALIZED, because they are and were valid for the tests and test conditions under which they were held, only. Few if any have been verified independently by other researchers. Some have, but not any that have looked into the sorts of issues that are being broadly painted as "phoolery".

Some DBT in audio clearly have been valid - like the ones that helped to create the MP3 codec. However, that is designed to fool the ear, not find the limits of audible subtleties.

If it was as simple as you say, then there would only be the need for ONE amplifier, since it is easy to get below 0.001% distortion using some basic circuit design techiniques, right? One preamp too. Ignoring "features" for the moment.

Is everyone who buys this equipment STUIPID and GULLIBLE?
Why do EEs who design opamps and power amps keep making different designs, attempting to improve slightly upon a previous one? Are they all STUPID and GULLIBLE too? Aren't the opamps that exist today good enough? Why build new ones with measured distortion figures that are fractions of 0.001% as AD and LT have done?? Are they also STUPID and GULLIBLE? I mean, really, it can't be heard, right??

Painting everyone and everything in the world of audio as "phoolery" is as inane as AM'ers calling everyone who operates SSB as "slopbucketeer", and the SSB operators calling AM'er similar epithets. Why?, because it paints ALL the people who are engaged in the hobby as STUPID and/or GULLIBLE or worse.

Time to stop this.

                      _-_-bear

[k4kyv]

Now, after doing all the things you suggested above, what would you do or say if YOU were listening and someone came in and changed ONLY the AC power cords and YOU heard the sound change? Of course you can claim that you wouldn't hear it. But what if you did? Then what? 

I would rig up a jig where I could instantly switch between power cord A and power cord B. Then I would meter the power supply voltage, ripple and noise content, the DC output voltage and noise measurements from the supply.  Maybe monitor the power supply output with a scope. If anything changed, I would zero in on the power cord to see what was different about the two. I also would monitor the audio output with a scope to see what changes in waveform occurred. If something about a power cord affects the audio output from the amplifier, then something drastic is occurring at the a.c. input of the amplifier - probably excessive voltage drop -  not hard to find with simple a.c. instruments.  If no difference was  found, and the scope pattern at the output of the amplifier was unchanged, I would admit to suffering from a placebo effect. Maybe bring someone else in to listen to the A-B comparison without telling them what was  being changed to see if they heard the same thing.

If the other person also heard the  difference but none of the instruments indicated any difference in any of the waveforms or other parameters, I would then start believing in ghosts, witches and other paranormals, purchase a set of tarot cards and maybe start to keep a lookout for UFOs with Elvis on board.

[KB2WIG]

"  UFOs with Elvis on board.  "

Elvis is not on board.. I'm suprised that you do not know that Elvis uses mind controll to operate the UFOs.


klc

[WBear2GCR]

Now, after doing all the things you suggested above, what would you do or say if YOU were listening and someone came in and changed ONLY the AC power cords and YOU heard the sound change? Of course you can claim that you wouldn't hear it. But what if you did? Then what? 

I would rig up a jig where I could instantly switch between power cord A and power cord B. Then I would meter the power supply voltage, ripple and noise content, the DC output voltage and noise measurements from the supply.  Maybe monitor the power supply output with a scope. If anything changed, I would zero in on the power cord to see what was different about the two. I also would monitor the audio output with a scope to see what changes in waveform occurred. If something about a power cord affects the audio output from the amplifier, then something drastic is occurring at the a.c. input of the amplifier - probably excessive voltage drop -  not hard to find with simple a.c. instruments.  If no difference was  found, and the scope pattern at the output of the amplifier was unchanged, I would admit to suffering from a placebo effect. Maybe bring someone else in to listen to the A-B comparison without telling them what was  being changed to see if they heard the same thing.

If the other person also heard the  difference but none of the instruments indicated any difference in any of the waveforms or other parameters, I would then start believing in ghosts, witches and other paranormals, purchase a set of tarot cards and maybe start to keep a lookout for UFOs with Elvis on board.

Don, you have put ur finger on the problem rather nicely.

One can often see "differences" in waveforms, but correlating differences observed on test instruments to the perceived sound is something that has yet to be done by anyone.

Scopes are insufficient, although useful, for this sort of comparison. It's more revealing for example to look at the spectra of distortion down near the noise floor... like within 20dB of the noise floor... so an FFT usually will show more than a scope waveform. Realtime spectrum analyzers are more like it... but still may only give glimpses of what one needs to be looking at. Why look at such low level signals? They seem to be audible to the extent that it has been shown that the spectra of distortion in otherwise low distortion amplifiers correlates to the perceived sound quality - NOT the absolute value of distortion!

In fact there has been extensive discussion on the sonic effects of things like switches and relay contacts. It's not voodoo.

But as I said, for most people in most situations, it makes no difference at all. Like if you listen to a Bose Waveradio or a mid-fi stereo, or a typical home theater setup, it's all moot.

                  _-_-bear

[W7TFO]

"A Spaniard in the works"...

Suppose you have a 1kW AM transmitter.  It is operating perfectly on single phase power.

Rebuild the power supply to use wye or closed delta three phase, with full wave rectification.

Your ripple freq goes up, the duty cycle of the filter parts changes, but does the RF it makes change?

73DG

[WBear2GCR]

The question of the RF changing is rather irrelevant. It may well change. But it doesn't matter. A red herring.

            _-_-bear

[KA3EKH]

Only if you use oxygen free cable in the primary circuit! That AM sound has more clarity and a cretin brilliance you just don’t get with regular copper, and it's just shrill with aluminum! Back in the eighties I was doing contract work for a little hell hole of a class A FM station in Delaware and some hack came around to all the stations in the market selling base band peak limiters, a hideous little box that pumped the base band and diode limited it so you can make the station louder. I was working there late on Sunday night and went to install the new limiter but found out I was short a BNC to BNC cable, so I installed the box in the audio rack and plugged it in right under the optomod and went home.  The next time I was there  three or four days later the general manager and the PD told me that the new limiter allowed them to be heard more clearly and in places the station was not usually received and that $300 box was the best investment ever! Funny thing was other then the power cord it was not connected to anything, perhaps its beneficial effects were coupled into the audio chain by the power cord?

[WQ9E]

I could believe that the power cord could impact the audio reproduction IF the original power cord was woefully inadequate to supply sufficient current resulting in reduced voltage regulation on the DC side of the supply.  This will NOT be the case with any standard power cord included as original equipment.

The gear is being fed filtered DC by the power supply and this is going to swamp the impact of any magic fairy dust sprinkled on the power cord. 

There will always be a market for gas line magnets and other such nonsense.  Sometimes I think instead of doing some fairly difficult and involved consulting work I should put my marketing degrees to use developing and selling some high end magic product.  Unfortunately this nagging sense of ethics gets in my way.

[KL7OF]

There are advantages to being hearing impaired.......however, I can still enjoy the music

[WBear2GCR]

Gee, tough crowd. You folks - not all of you - but a whole lot of you are awfully stubborn.

Let me ask what's the difference between a "fiddle" and a Stradivarius?

How come no one has exactly been able to match the original after all this time and tons of research? Don't all violins sound the same?

Just to nail this down, it's not a case of "placebo effect".
And to say it AGAIN, let's put aside the BS marketing and the price charged and just deal with the basic issue?

No one has to agree with me, but it's still not proper to insist that everything in the world of audio that is not simple engineering is going to be nonsense and "phoolery". It's just not.

I'll bet that no one who has posted about how this just can't be real has bothered to take a serious look at the things posted in the link I provided a few posts back, right? Why confuse me with the facts, my mind is made up, eh? Tsk, tsk.

                        _-_-bear



PS. I must be really making friends now!

[k4kyv]

I'll bet that no one who has posted about how this just can't be real has bothered to take a serious look at the things posted in the link I provided a few posts back, right? Why confuse me with the facts, my mind is made up, eh? Tsk, tsk  

I opened the link, but nothing in the list of topics suggests anything about power cords or their effects on the audio.  I didn't bother with the tedium of opening each thread and sorting through all the responses hoping to find some incidental mention of the subject.

Still, I am waiting to hear some attempt to explain what is special about the 6' power cord that makes it any different from the tens of feet of Romex running between the entrance panel and the mains outlet, and how the power cord can magically nullify all the deleterious effects of the cheap, consumer-grade copper conductors in the Romex, deleterious effects that would be no different from the deleterious effect of an ordinary $6.00 power cord made out of zip cord and a cheap male outlet plug.

Gee, tough crowd. You folks - not all of you - but a whole lot of you are awfully stubborn.

Not stubborn, just flying by our own years of hands-on experience with radio, audio and electronics, plus what we have managed to glean from the electrical/electronics/radio/audio engineering books and IRE/IEEE Proceedings we have accumulated over the decades in our libraries.

Let me ask what's the difference between a "fiddle" and a Stradivarius?

The handle attached to the carrying case may have an "astounding" effect on the "tessitura" of the violin contained therein. Let us sell you one of our $1,000 carrying-case handles to replace the one on yours, and you will be amazed at the difference it makes in the sound of the violin the next time you take it out of the case and play it. We can't explain why the handle on a violin case would affect the sound of the violin inside; that's just a fact we observe.

See our latest catalogue for our "high-end" sheet music paper.  Only $10 per sheet and we give you a discount if you purchase a 500-sheet ream. Guaranteed to add warmth to your musical talent when you have your sheet music transferred to our acid-free paper stock. [/quote]

[N0WVA]

The UFO's are real, but they are not "objects".

http://en.wikipedia.org/wiki/Harley_Rutledge

I have two copies of his book. If you would like to read it, Ill send one to you.

If the other person also heard the  difference but none of the instruments indicated any difference in any of the waveforms or other parameters, I would then start believing in ghosts, witches and other paranormals, purchase a set of tarot cards and maybe start to keep a lookout for UFOs with Elvis on board.

[WBear2GCR]

Don, did you use the search function?
Did you read anything else?
My point is that there is all sorts of seemingly minor things that effect sound, and they are mentioned in various threads.
Saying I looked at the topics that are current and didn't see it is akin to coming on here and saying that what I was looking to find out about wasn't immediately apparent.

That should be pretty self evident?

In fact why don't you register, post the topic and field the responses? People are nice enough, and the board is moderated, things stay as much or more on topic as they do here. Post and ask!

--------------------

The handle on the violin case has no direct connection to the violin, how it plays or how it sounds. The power cord at least is connected to the unit.

What about a violin bow? Why do professional violinists pay THOUSANDS of dollars for a bow?  It's just horsehair and wood! Phools??

Again, if subtlety is irrelevant than so be it.

Now, speaking in general terms about audio reproduction... the quality of source material has substantially improved in the last 10 years with the advent of 24/192 AD/DA being available all over the place. Also the quality of drivers has improved with the advent of better measurement gear and FEM simulations. So, it is far easier for far more people to gain access to source and playback of higher quality than was available commonly, even in the best studios only a few years ago.

Just like you now may be watching 1080p flat screen TVs, you can now see far more detail than you could with ur NTSC crt based TV.  Speaking of which, how good does ur old VHS tape look now on ur new 1080p screen? That 1080p screen isn't so good. Something around a 4k is starting to be equal to what you get with a good 35mm color slide... I was working with 4k resolution still images and CRT monitors 25 years ago doing computer graphics, NTSC looked like crap to me then... can you start to see the relationships now?

Phew.

                 _-_-bear

[w3jn]

Bear, every time we go down this road it's the same.  Nobody's going to convince you this is snake oil and you're not going to convince them it's not.

As for me, I'm fully convinced there are indeed audio subtleties.  I am just as fully convinced that "oxygen free wire", high end power cords, and specially treated wooden knobs do not contribute one way or the other to these subtleties.

What exactly is "oxygen free" wire, anyway 

[W1ATR]

http://en.wikipedia.org/wiki/Oxygen-free_copper

I like the tubes in my radios to be of the oxygen free type. They normally work much better. 

[WBear2GCR]

John, there is/was a company in Japan whose business was/is to develop and market copper wire made from a single copper crystal! Mono-crystalline wire! 


      ------------------------


I don't expect to convince anyone of anything by talking about something you have to hear... but I would like folks to limit the "shotgun" being applied to the topic and the people involved.

As far as wood knobs, they would likely have zero effect on my attenuators, since they are spring loaded step attenuators with wiping contacts... folks with regular old carbon or plastic pots might notice a change with a wood (or rubber?) knob over a metal one since the wiper on the pot is a point contact and the vibrations in the air (sound) will be sent down the shaft and wiggle the contact. Of course you could argue that the effect is inaudible, but I am sure it can be measured. And wood knobs do look nice and feel good.

But quite frankly anyone who is thinking of buying an expensive knob for sonic reasons ought to buy a better pot or install a stepped attenuator in the hole first...

No one forces anyone to patronize those sellers who make questionable products. I too put some of these products and claims along side the folks who sell "crystals" and other things to effect the cosmic ether around you... I certainly do NOT patronize them.

                  _-_-bear