Had an interesting conversation with an E-E,Telecomm guy concerning "Cables" (1 Viewer)

[Brett DiMichele]

A friend of mine at work who is the main Telecomm guy who
also holds a degree in electrical engineering, stopped by
today and I got him on the topic of home audio and cables.
We talked about interconnects and speaker wires and power
wires and when I told him the things I read here he about
wet his pants.
NOTICE: Before this turns into a "My $2000.00 power cable
DID make a diffrence" thread please be aware that I agree
a high quality cable can sometimes make a diffrence.
The main point was that if the unit was designed with a
heavy enough power cord from the manufacturer than you will
not see any diffrence in performance and he means measuring
performance not what "you" perceive is happening.
We both agreed that you can see dramatic increases in
speaker performance when using high quality compoents and
woefuly inadequate wire. But when I told him some of the
prices his jaw dropped. Being that he's the lead man for
Telecomm he deals with every kind of coax and network cable
and wire known to man and he thought some of the prices I
quoted were nuts. He also thought some other prices were
very reasonable and I agree with him.
All in all it was great to chat with someone in detail who
knows electronics and wiring and measurable factors of both.
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Brett DiMichele
My Home Theater Site!
[email protected]

 

[Jay Mitchosky]

This speaks to the long standing debate between the engineer/scientific types and the cable supporters. The former will, in general, maintain that there is no audible difference past a certain measurable point. The latter will remain unconvinced and continue to support that cables can and do make a difference. You'll watch it unfold here. In my view the bottom line is this (voiced so many times by our own Mike Knapp): perception is reality. If you can hear a difference, there is a difference, regardless of what the measurements tell you. That's not to say that I would be inclined to spend $2K on a power cable, but for those who do, and for those who can realize its impact, I cannot dispute their claim. Perception is an individual thing.
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--Jay
"No one can hear when you're screaming in digital."
My Home Theatre Pictures...
"You're no messiah. You're, you're a movie of the week. You're a ... t-shirt, at best."

 

[Guy Kuo]

Egaads. We walked into the trip wire again! (Holding my ears for the boom)

 

[Mike Witt]

Below is a post from audioasylum.com concerning power cord effects. I am not claiming to adhere to these opinions, I am simply posting this here because I think it is very interesting reading. You make up your own mind. I'm not fighting these wire wars (but I do get a chuckle out of watching some of them ).
>>>AC Power Cord Effects
So, how in the world can a power cord make any difference, if it is properly rated for the current draw, and is UL listed?
Like many questions about audio systems, this one seems very logical and reasonable. Just use Ohm's Law to calculate the current draw, and viola, we have the voltage drop, and we have the cold hard facts, Yes?
No.
Like many overly simplistic answers, this one does not take into account all the facts. Let's look at a hypothetical power amp to start. Lets say it is a moderately high power design, and is rated to draw about 8 amps from the wall at full rated power. That's about 960 watts from the wall. We won't even get into side issues of switching power supplies, which play total havoc with the simple Ohm's Law approach, we will stick to linear power supplies.
So if the AC cord is UL listed for 10 amps, it is likely an 18 gauge cord. Many 18 gauge power cords are rated for 10 amps of current. How is this rating determined? By how hot the cord gets while carrying the rated current, NOT how much voltage drop there is.
In our hypothetical amplifier, the RMS voltage drop in the 6 foot cord would be approx. 1/3 of a volt according to Ohm's Law. This does not take into account the wall outlet contact, or the IEC connectors if present, nor does it take into account any other factors, just the resistance of the 18 gauge wires in the AC cord.
On the face of it, this seems quite harmless. How could a third of a volt make any difference? Well, because the voltage drop is NOT 1/3 of a volt! Has Ohm's Law been repealed? Are engineers all insane?
No, just an overly simplified analysis that failed to take into account ALL the factors. So what could possibly make that much difference. Well, for one, it would help to know that linear power supplies refresh their DC reservior from the AC line in bursts of current, current peaks that are in time with the peaks of the AC line. That is when the filter capacitors are refilled, when the AC line voltage its it's peak value, and the output from the secondary reaches a level above that which the PS capacitors have been drained to. Instead of a nice steady drain of 8 amps, we have current peaks that
last only for a brief moment, and the 8 amps is an RMS amount.
What this means is that because the current is being drawn only for a fraction of the AC voltage cycle, or for about 1 thousandth of a second (one half cycle lasts for 0.0083 seconds). The peak currents can easily reach ten times the RMS value. What is the voltage drop for 80 amps? At this point, the resistance of the AC plug contacts, and even the bond inside the cord between the plugs and the internal wires become a significant factor. It is not hard for the voltage drop to reach 5 volts or more. The AC line peaks never reach the full value, because the line cord has lost some of it.
Power amps depend on receiving the full measure of AC line for their full rated power, so such a drop will reduce the actual output power in a seemingly disproportionate amount. A 200 W amp may be reduced to 170 watts before clipping.
The above (still simplified) analysis assumes a steady signal, and a steady current draw. Musaical dynamics make it a much less consistent thing, and the dynamic demands will cause dynamic perturbations.
This is not the only effect on the power amp. These current peaks can easily cause AC line distortion, and the heavy current draw can generate harmonics on the line, the hash from the rectifier diodes can increase, a whole series of events occurs that are not immediately obvious just by thinking of the amp as a simple resistor and using Ohm's law.
Most house wiring is either 12 gauge or 14 gauge, while many OEM cords are 18 or at best, 16 gauge. Most OEM cords do not have shielding or any provision for reducing radiated EM fields, do not have premium AC outlet plugs or premium IEC plugs for better electrical contact at these junctions.
So what happens with a bigger power cord? Replace that 18 gauge cord with a 14 gauge cord, and the voltage drop will go down by a factor of about 2 and a half.
Include shielding in that cord, and the possiblity of radiated EMI/RFI goes down compared to an unshielded cord.
Shielding and radiated EM fields might not seem relevant since the house wiring has neither advantage. However, the house wiring is not laying right next to the other component's AC line cords, or right next to the line level or speaker interconnects. Reduced levels of induced RFI and radiated EMI/hum fields would not hurt SOTA sound reproduction.
Since the AC power cord is usually laying right in there with all the other AC cords, and probably the speaker cables, and the interconnects (some people even bundle them all together for neatness, OUCH!), it is quite possible that a premium AC cord will help reduce interference in the system, and raise the amount of power available before clipping,
and smooth any AC line distortions, etc.
This is all without even going into secondary effects, or other more esoteric aspects. Just a more nearly correct way of applying Ohm's Law to the real situation. Add in ferrite filters, built-in filter components, shielding effects, and the esoteric aspects, and it should be obvious that AC cords are not at all simple, nor are they a no-brainer.
There is the issue of resonant situations. Certain power cords and power supply transformer primaries might tend to resonate at RF or high frequencies. This resonance might make RFI/EMI problems worse, changing to a different cord will change the resonant frequency, and change the RFI/EMI effects.
The plugs are not a trivial issue either, and may be more responsible for sonic improvements than the other factors.
Hubbel and other premium plugs and sockets will increase contact area and pressure, reducing contact resistance and other contact related problems. It has been claimed that poor AC plug contact can cause micro-arcing, with it's attendant hash being injected directly into the audio component.
It is not as simple as just simple wire resistance. The connection at each end of the cord adds resistance, the wall outlet socket adds resistance, etc.
For the raw wire, round trip:
12 gauge, approx. 6 feet = 0.0206 ohms
14 gauge, approx. 6 feet = 0.0328 ohms
standard AC power cord
18 gauge, approx. 6 feet = 0.0830 ohms
Measuring real AC power cords, I get around 0.128 ohms for an IEC 18 gauge power cord, and about 0.022 ohms for a 12 gauge IEC cord, not including the AC wall socket connection.
Why is the 18 gauge resistance so much higher than just the wire resistance? Ever tear one of those cheap cords apart? Poorly crimped or barely soldered connections are responsible for the bulk of the extra resistance.
Preamps and CD players all have their special requirements: CD players require shielding to help keep the digital hash that back-feeds from the circuitry out of the rest of the equipment, preamps need a nice steady voltage for minimum noise, and freedom from RFI, etc.
Fancy AC power cord geometries might also reduce the inductance of the 6-8 feet of line cord, raising the available voltages. but this would be limited to the ratio between the length of the power cord vs. the wall run. Such geometries often reduce the radiated energy, and aid shielding of the cord.
Some power cords might have a built-in filtering action, like the water jacketed ones, that have the conductors and insulation surrounded by a conductive fluid. This fluid might short out and reduce/damp any EM fields the cord would conduct to the component besides the 60 Hz AC power signal.
It also helps to keep in mind that we are not supplying a Sears rack system, that any system which aspires toward the SOTA is going to be more sensitive to minute effects and minute improvements. How much does a big fat shielded power cord help things? Probably about as much as upgrading from an OEM interconnect or zip cord speaker cable to
some decent aftermarket cables, some systems are more sensitive to AC cords, some are less sensitive to cords.
As always, the bottom line is: you have to listen for yourself, and see if their is any benefit for you, on your system, with your listening habits.
Do AC cords have the potential to influence high end sound? Yes. Does anyone who believes this also believe that high end cord costs are justified? No.
In my DIY AC Cord note, I recommend an $11 shielded heavy duty Belden (now Volex) cord, not a thousand dollar high end cord.
See my DIY AC cord note at: http://members.nbci.com/Jon_Risch/ac-cords.htm
Some of the cord/cable manufacturers get carried away with using only the very finest materials and assembly techniques, carrying over the technology and costs from their high end audio interconnects and speaker cables.
Is this necessary? I don't know, I will not discount it out of hand. Does it make the cords cost a lot? Yes.
Does this make them dishonest or imply that they are deliberately trying bilk the customer? Not at all.
Jon Risch

 

[John Morris]

If you are a serious tweaker, and am looking at upgrading your power cords, you may want to consider getting a power conditioner first, and then upgrade your power cords later. It doesn't matter how good your power cords are, if the power feeding those cords is crappy.
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Take Care,
merc
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Link Removed
God Bless America!!!

 

[John Morris]

The other thing I noticed is that in Mikes' post he quotes Jon Risch as recommending an $11 Beldon cord, yet JR now sells this cord, or one like it, for $64. LOL! It MUST be due to inflation...
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Take Care,
merc
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Link Removed
God Bless America!!!

 

[Mike Knapp]

Asking an EE about cables is like asking a clergyman about the viability of athesim. Their training has a narrow focus and they will always fall back on their training. They are trained ti think inside their boxes. This should not surprise anyone. What surprises me is when an EE actually sides with the "difference" camps.
I have already mentioned many times that the primary objection by the skeptics is the cost of the boutique cables (as proven by your experience) If all cables cost the same there would not be these discussions at all. To object to something based on cost is a prejudice with a socio-economic foundation.
Imagination is far more valuable than knowledge. Albert Einstein
Mike

 

[Brian OK]

John,
Be nice. And be fair too.
JR DOES NOT SELL AC cords. Kevin Haskins of www.diycables.com sells them using Bob Crumps old reference recipe from nearly 20 years ago. Jon had recommended the Belden (Belden 19364, 14/3 SJT) cable and the Pass&Seymour 5266-X wall plug in the AA Cable forum LONG before Bob Crump was kind enough to divulge his recipe last year in the Cable Asylum for all the world to see, and copy if they felt so inclined.
Kevin simply pursued the recipe with Mr. Crump and was given the exact assembly instructions which Bob DID NOT divulge when he listed the cables ingredients.
For Kevin to assemble the cable, it takes hand soldering,Q-Dope on the solder joints and some further hand assembly. Not a 20 minute cob-job.
Furthermore, Kevin uses the proceeds from his cable sales to fund his (and his wife) charity which allows underprivileged Guatamalian children to be adopted by US families. Kevin adopted a child last year. And it costs money (10k+) to do this.
When I bought my 2 cords from Kevin last year, I sent $75. per cable. I overpaid because I just respect what he is doing.
Again, JR does not garner any proceeds from AA. He is just a very generous guy with his time and his ideas.
Geesh,
BOK
PS Wayne at bolder cables also sells JR recipe cables.

 

[Henry Carmona]

I have already mentioned many times that the primary objection by the skeptics is the cost of the boutique cables (as proven by your experience) If all cables cost the same there would not be these discussions at all. To object to something based on cost is a prejudice with a socio-economic foundation.

So be it, but there is only a finite number of materials available for these type of wires/cables, and there are only so many methods of putting one together.
There has to be a limit before cost becomes soley reflective of name brand and overhead
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"Charlie don't surf."

 

[Saurav]

Um... just a technicality, but was he a networking/datacom engineer or a telecom engineer? In my experience, there certainly is a difference, especially with their outlook on digital electronics. My definition of telecommunications is anyone dealing with transporting voice electronically. Internet and data transmission isn't telecom, and more importantly, it's different enough that the same rules don't apply in both worlds. Which is not to discredit your friend, I'm a telecom engineer and I have a good laugh at prices in the cable section every time I get my Audio Advisor catalog.
And did you talk to him about jitter?

 

[KeithH]

Mike, let me start off by saying that I am not siding against you. I have no opinion as to whether or not changing power cords has any effect, as I have not tried any audiophile-preferred after-market cords. I do agree with you that price is a key reason why many people dismiss audiophile brand interconnects, speaker cables, and power cords out of hand. While audiophile-grade power cords may yield a performance benefit, I feel they are overpriced. I can't imagine what is put into a power cord to justify a $500 or greater price tag. That's the problem I have. A $500 power cord may improve the sonics, but I will not pay $500 for it, plain and simple. Truthfully, I have a similar problem when it comes to interconnects, though I am more apt to try expensive interconnects because there is another issue with changing power cords besides price.
The other problem I think people wrestle with in regards to power cords is that few of us can change them throughout our system. Many components have hardwired power cords, and the vast majority of people are not skilled in modifying components to have detachable cords and are unwilling to pay someone to do it. It's worth noting that such a modification voids the warranty. As an example, I think people question changing the power cord on a CD player if their amp (pre-amp and power amp, integrated amp, etc.) has a hardwired power cord. This concerns me in my main stereo system. I could change the power cord on my Sony SCD-777ES SACD player, but not on my NAD C 370 integrated amp. I am not about to upgrade the amp, by the way. So, I question how much of a benefit I would realize just from changing the power cord on the SACD player. Again, the high price of power cords is preventing me from becoming curious.
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My:
HT Pics ; Equipment List ; DVD Collection ; LD Collection
KeithH: Saving the Home Theater World Before Bedtime

 

[John Morris]

Brian: Hey, when I'm wrong, I'm wrong. And in this case I'm wrong. I am thinking about upgrading my power cords and so in my reading I saw in a post that someone said JR's cables were for sale at http://www.diycable.com
God Bless America!!!

 

[Mark Rich]

Nice to hear that you are big enough to admit you were wrong. An admirable quality from an elitist
Actually I think you were referring to my post about JR. Think I stated that diycable(s) offers a JR design. Not Diycable was JR. The good about JR is he doesn't sell anything (unless he works for Belden - just kidding). Just offers his advise and experience. FYI I think Diycable is now going fully commercial and is not doing it as a non- profit operation. This does not take away from what they started out doing. A fine company that sells good products.

 

[Brian OK]

John,
Not a big deal at all. No need to apologize.
I hope you do try to "roll your own" cables. Please find links attached where you can source direct the wall plug and IEC which is used in the Asylum cord. You said you have the Belden 19364 already (that's good because you can only buy it in 250' rolls on the web, OUCH!).
Pass&Seymour 5266-X wall plug ---
If you have a Menards store near you try there. Otherwise go to www.wescodist.com
First register, password and all
Next do search for Pass&Seymour 5266-X ($8.35 ea.)
Schurter 4300.0603 IEC connector ---
go to www.alliedelec.com
Do a search under Allied Stock #, and type in 509-1215
Cost is $7.00 ea.
Next you may want to do a search at AA under Cables with "asylum cable" for assembly pointers.
Good Luck,
BOK
PS --- seems Kevin is still using the diy.cable proceeds for what he and his wife truly believe in
www.harmonicdiscord.com/forums/viewtopic.php?topic=290&forum=19&8

 

[Mark Rich]

Yes he is still supporting his charity. Just commenting on a post of his about future ( current?) changes to his company. Nothing changes. STill admire the man and his motives. http://www.audioasylum.com/audio/cab...ges/30183.html

 

[Bhagi Katbamna]

Cables probably have the highest mark-up of any necessary(meaning that you absolutely have to have them to be able to hear your system) device. I have tried various cables(detailed in the 10 page cable post) and not heard a difference.
Many cable companies don't even make their cables, don't take my word for it look at this website: http://www.high-endaudio.com/magaz.html
Here is an excerpt from that page:
AUDIO CABLES-THE ULTIMATE TEST OF INTEGRITY
There is no subject or component category that has been as revealing of the magazines' (and their reviewers') integrity as audio cables. In less than 20 years audio cables have gone from an afterthought to a major investment in most systems. The prices have also skyrocketed from less than $ 50 to many thousands for the (so-called) "best".
Simultaneously, the cable companies have slowly become one of the largest advertisers in almost every audio magazine. In return, these magazines have published 'reviews', and "recommendations", of the "better known" (most heavily advertised) brands and models. Virtually nothing else has been printed about audio cables by them. (There is one magazine, The Audio Critic, that claims that all cables sound the same. They don't receive cable advertising.) So, one may ask, where is the problem with the magazines' self-proclaimed integrity? They're honest and open, aren't they?
Well, prepare yourself for a totally new perspective about audio cables and the audio magazines:
LACK OF BASIC INFORMATION
I used the expression "cable companies" in the above paragraph. Did you think it was an oversight on my part that I didn't use the word "manufacturer" instead? After all, that is the word that all the magazines (and the 'reviewers') use, or at least imply. I didn't use it for a very good reason: It is not true. What is the truth? That's very simple:
Virtually every cable company you have ever heard of (or ever will hear of) does NOT make its own cables.
Are you surprised, or even shocked by this statement? Don't worry, I was too, and remember, I have been in the audio business for more than 20 years. In fact, I even discovered (from the actual manufacturers) that many cable companies don't even design their own cables. They just choose among different designs, materials, colors, terminations and the overall volume (total length). Then they are quoted a price, and that's it. Some companies may do some custom terminations at their "factory", but that's all the "manufacturing" they'll ever do.
The magazines (and the reviewers) know all of this of course, but they make sure their readers don't. Why do they suppress such basic information from their own subscribers?
The magazines realize that the word "Manufacturer" implies huge initial expenditures and investments of time and money, plus true size and importance. Simply ordering 50 or 100 pairs of cable from some large, 50-year old manufacturing plant, at their normal volume discount, doesn't even begin to convey the same image of scale, the same sense of expertise and commitment, or earn the same amount of respect or prestige, does it?
It's obvious that anyone with some money to invest can do the same thing. Magazines don't want their readers to think that any of their advertisers are just "anyone". The only serious monetary "investments" any of these cable companies will ever make is in "marketing" their products.
LACK OF PROPER AND THOROUGH TESTING
Unlike most other components, audio cables are easy to compare with each other, and now even with a "straight bypass" (a direct connection of two components that bypasses the cables). It should be obvious to all that the closer any cable is to the bypass, the better that cable must be.
One cable company, Wireworld, came out with the Comparator, a device which allows any particular cable to be compared with both a "bypass" position and one other cable. They use it themselves at audio shows, and a few of their larger retailers also use it. (Audio 'reviewers' always avoid the Comparator at shows, during public hours, for fear of exposure.) There is another, older device, the ABX switcher, which also makes it very easy and convenient to compare cables with each othernot against a pure bypass.
How many magazines use these informative devices, including the (free for them) Wireworld Comparator, with its ultra-revealing bypass position? Easy answer: None of them! A few 'reviewers' used the Comparator once, when reviewing some of Wireworld's cable, and never mentioned it again.
Even when they did use the Comparator, the results were always "inconclusive"; all the cables just happened to be "equally different" from the bypass.
The fact that the magazines refuse to even make these simple tests, let alone publish the results, is irrefutable evidence of their continual efforts to protect the inferior models. This means the "inferiors" will still be able to sell their products, give away "review samples" and pay their bills, most importantly their numerous advertising (aka protection) invoices.
LACK OF COST/PRICE INQUIRY
As we enter this new decade, it is no longer even slightly surprising to see cables for thousands of dollars, even for short lengths. Some cables are now above $ 10,000 a pair. Just 15 years ago, the most expensive cables were all $ 200 or even less, and some of them even used pure silver. So what has happened?
Well, the cable companies discovered that some customers were prepared to pay more, a lot more. Even more important, they also found out that the magazines never questioned, let alone challenged, the prices they charged; $ 500, $ 1,000, $ 2,000, $ 5,000 etc. (Retailers weren't complaining either with this new development; A $ 200 sale became a $ 2,000 sale!)
No one, not even those cable companies that didn't advertise, was ever asked to justify their prices. It didn't matter what the cable was made of, or its build quality, or its terminations etc. No questions asked. Why?
The magazines are afraid, almost to the point of terror, that the readers/customers will discover that the markups on cables are now very similar to those on "illegal drugs", over 1,000%! The outraged reader may even lose his Audio Faith. (See the next subject below.)
LACK OF PRICE/PERFORMANCE COMPARISONS
The magazines' "don't ask, don't tell" policy doesn't stop there. For further protection, they will not even compare any of the (now rare) reasonably priced cables to any of the high-priced models, unless they already know that they are inferior (a fix). Why?
The magazines know that if even one low-priced cable is better, the entire myth that all high-quality cables must also be high-priced will be shattered, permanently.
The magazines have never compromised their "total package of protection" for the cable companies. That's why there exists today a "reference speaker cable", with "rave reviews", from a very well known "manufacturer", which retails at $ 9,500 for an 8' pair, while his own cost is less than $ 100 from the real cable manufacturer, and he can still "sleep like a baby". (Yes, under $ 100 dollars, including terminations!)
The above website is run by Arturo Salvatore(who actually does state that he hears differences in cables)

 

[Mark Rich]

Interesting and thought provoking post. Probably explains why I stick to basic, well designed/assembled cables with published and available specs (from the mfg). Nothing but good ingredients (core,insulation,shield and connectors) without the snake oil. That, and I cant afford the $1,000 cables As usual IMO.

 

[PaulKH]

Bhagi - excellent info, thanks. Is there NOWHERE that does scientific testing of cables?

 

[Nick G]

Paul, in regards to speaker wire testing, here is a link to get you started. Enjoy.
Regards, Nick
http://www.sundial.net/~rogerr/wire.htm

 

[RobertR]

Asking an EE about cables is like asking a clergyman about the viability of athesim.

Interesting analogy. It sounds to me like you're claiming that cables carry something OTHER than an electrical signal (which is, of course, easily analyzed by an EE). And that this "other" is something that is as impossible to detect as is something on the "spiritual" level.
In short, sounds like "believing is hearing".
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