The great power cord debate

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Psychicanimal

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The great power cord debate
« Reply #60 on: 15 May 2003, 03:28 pm »
Quote from: Jay S
FWIW, my silver Acme's were very bright at the start but with break in they became natural sounding.  Oh my, see what I just did, I associated audio properties with electricity.


Mine were broken in by plugging them to a refrigerator, but have not been used for audio.  Lak told me to give them five days to settle...

nathanm

The great power cord debate
« Reply #61 on: 15 May 2003, 03:39 pm »
Quote from: Psychicanimal
Using a fully naked woman leaves virtually nothing to the imagination.  She's got strong legs, man.  Are ewe afraid of strong women?


Oh boy, you really got me there with that one.  No actually, it's that I'm afraid of sausages.  Probably just the photo, though. :wink:

Quote
That photo was taken during a Miss Venezuela contest.  Her bikini "accidentally" came loose and a photographer took a Kodak moment... :mrgreen:


Yes, for the 16th time, we know! :roll:  By putting accidentally in quotes you seem to infer that she intentionally made her bikini fall off?  Is this correct?  Perhaps this was intended to "seal the deal" with the judges?  Did she win the competition as a result?  Best Bikini Wax Job award maybe?

Quote
I should scan and send you a picture of me and Yaxeni Oriquén, Central American & Caribbean female bodybuilding champion!  She's  extremely built--and from Venezuela, too!


Nope, that won't be necessary.  :P  Muscled chicks with glossy, tanned hides I find to be fairly repugnant.  Just my opinion of course.  If women that look like a well-oiled Eames lounge chair are your idea of attractive so be it.  I'll stick with the Domai-style ones myself. :D

Anyway, about these power cords...

The cord has to "settle" now, eh?  That's a new one, I'll have to remember that.

"Honey why is the milk frozen and the ice cream melted?"

"Oh sorry, looks like the power cord finally settled.  Probably have to re-adjust the controls now!"

Maybe they should put a warning on the box: "This power cord is rated for 30 amps, actual amperage may be lower due to settling during shipment"  You know, like cereal and potato chips?

Psychicanimal

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The great power cord debate
« Reply #62 on: 15 May 2003, 04:06 pm »
Nathan,

You are very funny--I truly enjoy reading your sarcasm.  That, however, inhibits you from advancing the sound quality in your system. If you came over to listen to my system the expression on your face would be anything but funny... :cry:

If you open up your mind you'll enjoy this more.  My understanding of audio these days is not the same as three or four weeks ago.  Something dramatic has happened since integrating the Elgar regenerator w/ the rest of my power delivery rig and getting Ridge Street Audio Midnight Silver Edition ICs--they use natural, organic insulation and are sooo transparent, fast and musical I never thought my system could sound the way it does.

Perhaps Van Alstine will hire you for public relations & marketing!

nathanm

The great power cord debate
« Reply #63 on: 15 May 2003, 05:54 pm »
:rotflmao:

Sarcasm is limiting the sound of my system?  Now I'm not sure which concept is more ludicrous; settling power cords or sarcasm affecting music playback! :lol:

The main factors that are most important to me are:

1. The music

2. The recording
 
3. The shape of the cabinet, type of drivers, and placement of the speakers

4. The shape, size and acoustic properties of the room

I am not saying power isn't important, of course it is.  But an expensive cord, if it is only wire, cannot do the things they claim.  Bare wire cannot filter noise.  The only reason people think exotic cords do something is because they LOOK COOL and you have spent LOTS OF MONEY on them and you'll be damned if you don't hear an improvement.  It's a mind game. Notice how nobody sells these overpriced cords to any industry besides audiophiles?  Since this unique group has correlated musical enjoyment with electronic equipment anything is possible regardless of wether or not it makes any sense.  Who else besides audiophiles would believe this malarkey?

I wouldn't say the effects of Pyschic's much-pimped 10 stone worth of power regulation devices are not doing anyhing beneficial, but I seriously doubt that cords alone are the key to musical enjoyment.

Quote from: Psychicanimal
If you came over to listen to my system the expression on your face would be anything but funny...

That may very well be.  You could put it in the Systems section so we can see what it is.  I'm sure I would enjoy listening to ANYONE's system here as long as they could average 85db at 10 feet away without fear of repercussion! :D  I would go so far as to say I would likely enjoy your system even if you swapped out several thousand dollars worth of pretty cords with plain black plastic ones!

OBF

The great power cord debate
« Reply #64 on: 15 May 2003, 06:29 pm »
Quote from: nathanm
I'm sure I would enjoy listening to ANYONE's system here as long as they could average 85db at 10 feet away without fear of repercussion!  


85db?  I thought you liked to rock out Nathan?  :D

audioengr

The great power cord debate
« Reply #65 on: 15 May 2003, 07:41 pm »
AVAHIFI wrote:

Quote
Regarding speaker cables and interconnects, much of the differences heard here are easily determined with a capacitor meter. The higher the capacitance of the cable, the brighter and "more detailed" it will sound to the listener. This is because the capacitive load slows down the output circuit and makes the feedback arrive later, which turns negative feedback into positive feedback, peaking the amplifier or preamp response. Poor shielding also adds hum and noise to the system. One can take a "high end" cable with a large capacitive load and add that same load to the output of the preamp or power amp with a 25 cent capacitor of the same value with standard two conductor zip cord used and get the same sonic results. Of course the brightness and detail is wrong, it was not part of the source material, just a non-linearity generated in the equipment trying to drive a capacitve load.


Frank - I believe that the higher the capacitance, the more rolled-off the frequency response will be (Low-pass filter), thus reducing brightness, not increasing brightness, particularly for IC's.  Amplifiers may react differently depending on the design, but typically the same.

As for capacitance affecting amplifier global negative feedback:  Feedback is usually sampled at the amp output which is typically very low impedance.  Unless there is instability, the feedback should not be affected much by the capacitance.  However, I would agree with your statement if the amp had relatively high output impedance and the capacitance of the cable was very large, such as Goertz designs.  Very system dependent.  Measurements are likely to vary a lot with different amplifiers.

Poor shielding by itself will not add hum to a system.  In fact, most hum is actually caused by ground-loops and multiple AC circuits in the ground loops.  However, poor shielding can contribute to RF pickup, mostly AM radio, but only if the location is susceptable (strong fields) and the ground-loops are large (1/4 wave resonance).  I have never experienced a system yet where unshielded cables could not be used, even long ones, and the hum completely eliminated with proper AC grounding and single AC circuit.  I used over 15 feet of unshielded IC's at CES with absolutely no noise.  Even the reviewers pulled the IC's and reconnected them to see that there was no change in noise.  My reference system uses entirely unshielded IC's, speaker cables and power cords.

audioengr

The great power cord debate
« Reply #66 on: 15 May 2003, 07:48 pm »
nathanm wrote:

Quote
But an expensive cord, if it is only wire, cannot do the things they claim. Bare wire cannot filter noise. The only reason people think exotic cords do something is because they LOOK COOL and you have spent LOTS OF MONEY on them and you'll be damned if you don't hear an improvement. It's a mind game. Notice how nobody sells these overpriced cords to any industry besides audiophiles? Since this unique group has correlated musical enjoyment with electronic equipment anything is possible regardless of wether or not it makes any sense. Who else besides audiophiles would believe this malarkey?


Nathan - my cords do not claim to filter noise, except for ground-loop common-mode noise.  This can be useful to break-up ground-loops into small segments thereby eliminating AM radio frequency resonance.  The wires themselves are merely low inductance and low resistance.  This is simple circuit analysis. Here is my theory and the analysis using ROMEX, rubber cords and one of my older power cords, the Magnum2:

Amplifiers demand current from the power-line when the capacitors in their power-supplies become momentarily discharged due to high-current transients in the music signal. This discharge condition must be quickly recharged from the power-line, through the power-supply transformer, or a voltage sag will occur. Such voltage sags can cause audible distortion at the loudspeakers. If the power-line has significant series inductance in the path from the power panel to the amplifier, this can prevent the capacitor bank from recharging in time to prevent a voltage sag from occurring at the amplifier output transistors. With a low-inductance cable, the voltage drop across the cable will be insignificant during high-current transients, minimizing the voltage sag. This allows all of the current needed by the output transistors to be supplied when they need it, resulting in  fast, dynamic response to transient signals.

A typical 6-foot 14 AWG rubber cord and 25 feet of ROMEX has inductance of 7.2 uH and resistance of 235 mohms, ignoring the plug resistance effect.  Therefore, the voltage drop at 20kHz will be I*(wL+R)= I*(.905+.235) = I*(1.14).  With a 6-foot Magnum2 and 25 feet of ROMEX, the inductance is 5.9 uH and the total resistance is 147 mohms.  This is an 18% reduction in inductance and a 37% reduction in resistance.  The voltage drop for this combination will be I(wL+R) = I(.741+.147) = I(.888).  So at a fixed dynamic current I, the voltage drop in the entire power feed at 20kHz is 22% smaller with a Magnum2 power cord.  I would consider 22% to be significant.  The reality is even more compelling.  When you add in lower plug and receptacle resistance and the fact that the di/dt on the power cord will have spectra well above 20kHz with some amplifiers, the low-inductance cord makes an even bigger difference.

Dan Banquer

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Power Cords
« Reply #67 on: 15 May 2003, 09:04 pm »
Great analysis; except that power cords only have to carry a frequency of 60 hz. It's current we are talking about here, and standard line cords do not have a problem doing this. There are two things that will start to matter in a power cord. Wire Awg, and shielding. Standard IEC power cords already use the three conductors in a twisted configuration so reduction in magnetic field is done.

nathanm

The great power cord debate
« Reply #68 on: 15 May 2003, 09:28 pm »
Audioengr:  I am not qualified to debate you on the electrical matters.   It's more Greek to me than the Audiophile Club of Athens newsletter!  I would first have to ask my friend to translate what you just said into layman's terms I can understand.  However, I will take a stab at interpreting this.

To be honest I am not sure why I would even care about a voltage drop at 20KHz because I can barely hear that frequency anyway.  What's really playing up there besides cymbal harmonics and noise?  It's not really my favorite octave of the spectrum!  I also am not clear about why a power cord which is carrying a 60Hz signal cares about any other frequency? Maybe I am not understanding it correctly?

I'm glad your site has technical information instead of gooey marketspeak about how the cables will enrich my life and all, but I personally cannot  fathom why an 18% reduction in inductance on some cord is worth a month's salary.  It looks like the cords are built Full Ass, which is good.  I salute you for that.  But a $419 entrance fee to the Emperical power cord club seems, oh I dunno...just a bit bonkers.  Yeah, I know people can spend money on whatever they want, yadda yadda, I just find the prices to be whacked.  Those figures are ones I would expect to pay for an electrician to come to my house and wire up stuff the way I want! Heh!

nathanm

nothing to do with PCs. So sue me.
« Reply #69 on: 15 May 2003, 09:39 pm »
Quote from: OBF
85db?  I thought you liked to rock out Nathan?  :D


Oops, I meant to add an extra 1 on the front of that! (kidding)  85db average SPL that is!  Not those loud percussive snare cracks and such!  85 is what I've usually seen mentioned in regards to how recording studios monitor the mix.  I love it loud, but it's a delicate balance.  Concerts are usually too loud.  I don't intend to go deaf in my house, but 85 in my room is what I would like to have it at.  Instead I keep it around 60-70db to be nice to the guy upstairs.  It depends on the tune of course.  The Fletcher Munson thingy plays a big role.  If the CD is really trebly then it can become grating at higher SPLs. (Pantera) A warmer-sounding one can beg to be cranked higher. (Morbid Angel)

eico1

The great power cord debate
« Reply #70 on: 15 May 2003, 09:49 pm »
AE,

How much capacitance would you need to add to an amplifier output to get a roll-off in the audio band?:) I think Frank's theory is more plausable.

steve

Psychicanimal

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The great power cord debate
« Reply #71 on: 16 May 2003, 02:38 am »
Quote from: nathanm
:rotflmao:

Sarcasm is limiting the sound of my system?  Now I'm not sure which concept is more ludicrous; settling power cords or sarcasm affecting music playback! :lol:



No, that's not what I wrote.  I wrote that your sarcasm limits you:

"You are very funny--I truly enjoy reading your sarcasm. That, however, inhibits you from advancing the sound quality in your system. If you came over to listen to my system the expression on your face would be anything but funny..."

It seems to me you are having reading comprehension *issues*.  Where have I stated that I use expensive power cords?  Quite the contrary, my viewpoint expressed over and over is that as power delivery/noise control improves, expensive power cords become irrelevant.

Why would I want Audioengineer's $400 power cord with filtered ground when I got my 95 lb, 220V ONEAC with "virtual ground" for $100?  I saw a new ONEAC like mine in eBay for $285, FOB Texas.

Pay attention to what I write and you will be able to advance the quality in your sound system on the cheap... :idea:

audioengr

The great power cord debate
« Reply #72 on: 16 May 2003, 05:32 am »
I believe that you would need a LOT of capacitance to get roll-off with most amplifiers.  However, a tube amp with a 20 ohm output impedance might not require much at all, maybe 1000 pF?

As for line current to an amplifier, the SPECTRA is definitely well beyond 60 Hz, trust me.  It has to be because the diodes in the rectifiers are only on for short periods every cycle.  By definition, the current is spikey with high-frequency spectra.  This is just common sense....

And as for the price of my power cords, the reviewers and my customers definitely feel that they are worth it and the labor involved in building them causes them to be expensive.  Until you have tried one, you have no experience to judge them.

avahifi

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The great power cord debate
« Reply #73 on: 16 May 2003, 12:40 pm »
More clarifications:

1.  I am NOT a measurement freak.  The final analysis is in the listening, the music.  However, we do use measurements to keep our listening honest and to not fool ourselves.

2.  Observations, if it measures bad, it is bad.  You may like what you hear, but then again, so does the guy on the back of the bus with the boom box turned up to full distort.  All things being equal, as you make the circuit more and more linear, you will likely like it better.

3.  If it measures good but sounds bad, it is bad too.  This simply means you have overlooked something important in the design and the measurement techniques are inadequate.

4.  If it measures good and sounds good, it likely still can be improved.  Thats why we are in business - reality has not be reached yet.

5.  Amplifiers and preamps are indeed sensitive to capacitive loads.  Put (for example) a 0.01 microfarad capacitor across the output of an amp or preamp and drive it with 20 KHz square waves and watch the overshoot and ringing at the output.  This occurs because the feedback is arriving late and going positive.  Worse case, a full bore meltdown, as in the case with early Threshold amplifiers when used with Polk Cobra cables.

6.  Poor shielding in an interconnect is very much audible.  For example, we cannot use Kimber silver twisted braided interconnect cables with our old Super Pas Three preamp with the power transformer mounted on the outside of the back panel (done to keep the tubes from picking up the magnetic fields from the transformer).  The combo has a hum level you can hear across the room because the transformer dumps 60 Hz into the badly shielded cables.

7.  Again I have no objections to a well shielded low capacitance interconnect cable, a heavy gauge power cable, or 8 guage speaker wires.  My only objection is to the snake oil claims and prices for such items when you can do it it with the same results from you local hardware store if you want to.  Magic is very expensive, always has been, always will be.

Frank Van Alstine

Dan Banquer

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Power cords
« Reply #74 on: 16 May 2003, 12:43 pm »
"As for line current to an amplifier, the SPECTRA is definitely well beyond 60 Hz, trust me. It has to be because the diodes in the rectifiers are only on for short periods every cycle. By definition, the current is spikey with high-frequency spectra. This is just common sense.... "
  I think we need to examine this statement more closely, because that is what happens in the SECONDARY of the transformer. Is this reflected back into the primary or the AC line?; yes it is. However;
I have a power amp that includes a commmon mode filter that has a whopping 500 millihenrys of inductance on the hot and neutral lines. Does this delay the AC line current enough to cause an actual problem? Consider this: My amp will do a minimum of 220 watts into 2 ohms at 20 kHz. The power supply is still in regulation and no break up exists. Given my amp can do this and the above far exceeds what musical program material will require, I am having a hard time with low inductance power cords.
  Let's take this issue one step further. My home computer has a 1500 mHz clock and a 400 watt switching power supply to run it. In that 400 watt switching power supply is an input filter using a fair amount of inductance. These filters are required by the FCC to limit conducted noise.
Will a low inductance power cord increase the speed of my computer?
 Odd how no one in the computer industry is talking about this remedy. They do talk about bulky software from the prince of darkness (Bill Gates) as a real bottleneck.
  I could go on from here and talk more about 100 Kilowatt radar transmitters, but I will stop here, for the moment.
 The point is the following. Super low inductance power cords have no better inherent properties than standard line cords. However; if you like the way they look or sound to you, be my guest.

audiojerry

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The great power cord debate
« Reply #75 on: 16 May 2003, 02:31 pm »
DB wrote:
Quote
Given my amp can do this and the above far exceeds what musical program material will require, I am having a hard time with low inductance power cords.


Dan, can you clarify this? Does this mean your amp has a hard time with low inductance power cords, or that you have a hard time understanding why someone would favor a low inductance pc?

I also wish there were some easy way to audition your amp.

nathanm

The great power cord debate
« Reply #76 on: 16 May 2003, 02:34 pm »
Huh?  Psychic, your quote quite plainly states that you enjoy reading my sarcasm but however that inhibits me from advancing the sound quality in my system.  Not me!  I feel the key word here is "system" whereas you think it is "me".  Reading comprehension issues?  :nono: It can be interpreted either way.  If you are suggesting sarcasm is limiting ME, the person in a general way; then I would have to say you've gone crackers.  Are you the audiophile psychaiatrist\counselor now? :? Sheesh!  I do see where you are coming from, though.  If you feel that sarcasm is limiting me from hearing differences in cords just as I believe faith is making you hear differences in cords, perhaps you would agree that maybe sound quality is just as much if not moreso in the mind of the listener?

I could just as easily say that gullibility, influence of advertising, faith and lack of sarcasm enables audiophiles to spend more money than necessary.  But of course, I would never say such a thing. :wink:

Quote from: Psychicanimal
No, that's not what I wrote.  I wrote that your sarcasm limits you:

"You are very funny--I truly enjoy reading your sarcasm. That, however, inhibits you from advancing the sound quality in your system. If you came over to listen to my system the expression on your face would be anything but funny..."


Sorry if I inferred anything about you using expensive cords.  The only thing I am protesting here are dubious or semi-dubious, highly expensive products that are not worth anywhere near the price.  No more or less than that.

Quote from: Psychicanimal
Why would I want Audioengineer's $400 power cord with filtered ground when I got my 95 lb, 220V ONEAC with "virtual ground" for $100? I saw a new ONEAC like mine in eBay for $285, FOB Texas.

Pay attention to what I write and you will be able to advance the quality in your sound system on the cheap...


Now you're sounding like an infomercial!  Hey, it's great you've got the power filtration thing going; I'm not debating that, but now it sounds like you are preaching that your way is the way to go.  Just take Psychicanimal's hand and he will lead you through green meadows to the halls of Audiophile Bliss! :jester:  Just joking... Anyway, I am indeed interested in something like a balanced isolation transformer for the claims of lowered noise and perhaps ground loop issues.  The only thing I think is balderdash is the idea that a cord by itself will help anything.  And more specifically, a cord that costs crazy ass cash! Heh!

Dan Banquer

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Power cords
« Reply #77 on: 16 May 2003, 02:55 pm »
Jerry; My amps do not have a hard time with low inductance power cords, and from the facts I have stated low inductance power cords are a non issue. I am also in general agreement with Frank VanAlstine on cables.

       "Magic is very expensive, always has been, always will be."

Psychicanimal

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The great power cord debate
« Reply #78 on: 16 May 2003, 03:21 pm »
You are very funny, indeed.

Psychology?  I've never had any psychological training.  What I mean is that your sarcastic ways inhibit you.  How so?  By making mockery before you digest the information given to you.  Kind of like coming from a prejudiced frame of mine, I'd say.

Regarding audio, it happens that I know what I'm doing--and I do because I listen to those who know more than me (overall or in specific areas) and constantly seek their opinions...

Power delivery/noise control is application specific, so there is no such thing as *my* way, dude!

¿Entiendes?  :o

eico1

The great power cord debate
« Reply #79 on: 16 May 2003, 03:54 pm »
AE,

20 Ohm and 100pf will give a -3dB of 8MHz, so I don't know about that being the problem. I think the effect you are describing with pc inductance is better described in terms of slew rate, not bandwidth. All that matters is the ps caps get charged during each cycle, which is easy to check on a scope while playing music.

steve