power cord

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Speedskater

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Re: power cord
« Reply #40 on: 7 Dec 2012, 10:09 pm »
"c-J' wrote:
"It shows that people who claim that cable do NOT make a difference asre plainly DELUDING themselves. Those that say that cables should not make a difference, are dead right."

I think that it needs a little editing:


"It shows that people who claim that cables DO NOT make a difference are plainly DELUDING themselves. Those that say that cables SHOULD NOT make a difference, are dead right."
« Last Edit: 8 Dec 2012, 01:30 pm by Speedskater »

cheap-Jack

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Re: power cord
« Reply #41 on: 7 Dec 2012, 10:19 pm »
Thanks.

So often my mind goes faster than my keyboarding.

c-J

James Romeyn

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Re: power cord
« Reply #42 on: 8 Dec 2012, 03:23 am »
Not to get too far off topic...I'm not married to any audio religion.  As a result I've switched back and forth several times from thinking any generic conductor equals cost no object to wanting quality better than generic.

The last time I thought the former was true is when I re-wired (pretty short lengths) a DPDT toggle with gold contacts (an absolute polarity switch).  I switched from Stan Warren's recipe to generic braided shield OFC unbalanced mic cable (Canare IIRC). 

The door was open to my wife's office next to the sound room where she worked on the computer.  Shortly after the music started she mentioned (absolutely no knowledge of any change) that something changed for the worse, making it sounded cloudy. 

I later confirmed her opinion with blind test swapping IC, which she properly identified several times.     

You have no idea how much hassle it was to rewire that switch box back to the SW recipe.

One of the world's great luthiers Rick Turner (Alembic principal, designed Grateful Dead's original live performance system, I used to play his original guitar creations when Alembic was on (Jordan?) ally south of Market/West of Van Ness in San Francisco ) endorses our primeVibe music instrument seasoning device.  When the subject arose of musicians who deny that seasoning improves wood performance he paused, laughed and said something like, "Well, not much you can say about that..."  If you know Rick you'll know it takes a deep turn in the conversation for him to pause (not a criticism at all but just a function of the quantity of his professional knowledge spanning several decades). 

Julf

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Re: power cord
« Reply #43 on: 8 Dec 2012, 09:34 am »
Plugging to the same tube power amp playing same music, the sonic difference was fairly distinctvie.

Interesting - but, again,  how is this relevant in the context of the hypex modules?

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(2) What you tested was like micky mouse when compared to a thorough Total Harmonic Distortion test of carried by the chief engineer Class D Audio at Philips Digital Systems Labs, published a few years back.

Do you have a reference / link?

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So this THD spectrum analysis test proved nothing.

Yet the conclusion of this test was:

"It shows that people who claim that cable do NOT make a difference asre plainly DELUDING themselves. Those that say that cables should not make a difference, are dead right."

So how did they arrive at that conclusion, if the test proved nothing?

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PS: Likewise, I built 6 pairs of audio interconnects using same 4N pure solid silver wire of German origin
      for my rig. No choice when one wants the best!

Good for you - but did you ABX them to see if it really made a difference?

Speedskater

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Re: power cord
« Reply #44 on: 8 Dec 2012, 01:42 pm »
It's from a paper or note that BP wrote back in 2004:

Summary

To recap: to make cables disappear from the sonic equation, all that is needed is balanced transmission combined with sub-1ohm output impedance line drivers. I would like to propose this as a standard for audiophile equipment makers.

It shows that people who claim that cables do not make a difference are plainly deluding themselves. On the other hand, those that say that cables should not make a difference, are dead right.

http://www.audiocircle.com/index.php?topic=19698.msg174460#msg174460

http://www.audioholics.com/education/cables/cable-distortion-and-dielectric-biasing-debunked

Julf

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Re: power cord
« Reply #45 on: 8 Dec 2012, 03:01 pm »
It's from a paper or note that BP wrote back in 2004

Ah, yes, and it is a great paper - of course, it only applies to interconnects, and I totally agree with the conclusions (when speaking of interconnects):

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to make cables disappear from the sonic equation, all that is needed is balanced transmission combined with sub-1ohm output impedance line drivers.

It shows that people who claim that cables do not make a difference are plainly deluding themselves. On the other hand, those that say that cables should not make a difference, are dead right.

So, in a well-designed system, cables don't make a difference. If they do, it is because of problems/compromises in the system.

I think the same applies to power cords, but even more so, so my thesis stands - the nc400/smps600 combination is well designed, and not sensitive to cable resistance or inductance (within reasonable limits).

I repeat my question - has anyone detected audible differences between different power cables and power connectors with the nc400/smps600 combo (unless using some exotic/weird cables with extremely high resistance/impedance)?

James Romeyn

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Re: power cord
« Reply #46 on: 8 Dec 2012, 05:08 pm »
I'll A-B power cords today.  Couldn't do it yesterday because anti-diffraction strips (synthetic felt 3/8" x 1") on monitors were removed and painted flat black.  If the difference is marked I'll request the wife participate in brief ABX test.

Full disclosure: Pure analog Trinaural Processor is center piece of this 3-ch system.  There is only one generic mains cord so test will be mono on the center channel alone, which is processed rather than summed mono.  L+R summed mono is ill-advised mono source for this or any known application because of phase anomalies. 

I'll turn off DEBRA (Distributed-EQ Bass Reflex Array) and run the monitors full range, with good power down to the mid-40s (Dynaudio Esotec 17WLQ mid bass, two per ch in vertical dipole array).  Stage depth in this Trinaural system with six identical monitors in vertical dipole array extends at least 75' beyond the front wall.  Obviously mono stage depth will be smaller, but it will be as good as a proper mono signal can be. 

cheap-Jack

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Re: power cord
« Reply #47 on: 8 Dec 2012, 06:17 pm »
Hi.

Good for you - but did you ABX them to see if it really made a difference?

Do you believe in ABX? Sorry, I don't.

Take eating as an analogy to ABX:- Do you NORMALLY eat with eyes masked & nose clamped?
Yes, technically we could. But do we still know what we are eating & still enjoy it?

The protocol of ABX is to test our listening in such an abnormal way so different from how we listen
since we are born.

A test of human adaptibilty, maybe. So do we walk upside down on our hands instead of on our feet normally? Is it a fair test to do something we never or very very seldom do & draw a conclusion on it????? :scratch:

c-J

werd

Re: power cord
« Reply #48 on: 8 Dec 2012, 06:41 pm »
Hi.
Do you believe in ABX? Sorry, I don't.

Take eating as an analogy to ABX:- Do you NORMALLY eat with eyes masked & nose clamped?
Yes, technically we could. But do we still know what we are eating & still enjoy it?

The protocol of ABX is to test our listening in such an abnormal way so different from how we listen
since we are born.

A test of human adaptibilty, maybe. So do we walk upside down on our hands instead of on our feet normally? Is it a fair test to do something we never or very very seldom do & draw a conclusion on it????? :scratch:

c-J

Yes abx testing is a sham usually. Only because to make judgment with hearing is a learned event. Abx testing relies on the fact that you will fail under the testing conditions present. The subject's hearing is usually not familiar with the gear or room they are being tested in, it's used in marketing and deceitful con arguments.

I do agree though that blind testing can be performed on a system that is well know to the test subject's hearing. Its kinda of pain in the ass but all that will happen is the person going to end up hearing the same thing if not under blind testing. they are going to be able to pick out differences and assign them to brand and even make type, so it's kinda of useless but maybe not entirely.

JerryLove

Re: power cord
« Reply #49 on: 8 Dec 2012, 07:53 pm »
Take eating as an analogy to ABX:- Do you NORMALLY eat with eyes masked & nose clamped?

Smell is part of taste, so the latter would be an inept analogy; but yes: that is exactly how brand taste-testing is done. Blind.

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Yes, technically we could. But do we still know what we are eating & still enjoy it?

Did you know that, when given wine that they are falsely told is expensive , taste testers virtually always report it as tasting better than the very same wine when they are told that it is inexpensive?

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A test of human adaptability, maybe. So do we walk upside down on our hands instead of on our feet normally? Is it a fair test to do something we never or very very seldom do & draw a conclusion on it????? :scratch:

You mean not seeing the power cable is completely interchangeable with listening while standing on your head?

When I don't tell you what power cable I plugged in: how is that something you never or very-very seldom do? Sitting in a chair and listening to music on speakers?

And if I switch it and don't tell you; and you don't notice any change in sound: how does it still sound better?

Analogies will get you around for a while, but they eventually break down... like a car.

cheap-Jack

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Re: power cord
« Reply #50 on: 8 Dec 2012, 07:57 pm »
Hi.
it's used in marketing and deceitful con arguments..

Bingo! You've hit the bull's-eye.

c-J

Speedskater

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Re: power cord
« Reply #51 on: 8 Dec 2012, 08:03 pm »
I don't know what test it is that you think is an ABX test,  but your descriptions have nothing to do with a good ABX test. 

The problem that people that often do ABX tests complain about,  is that the test is to sensitive and they have to spend a lot of time chasing the smallest of uncontrolled variables.

Julf

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Re: power cord
« Reply #52 on: 8 Dec 2012, 08:04 pm »
Do you believe in ABX? Sorry, I don't.

Is ABX perfect? No. Do you know a better way to avoid perceptual bias? Sorry, I don't.

I am sure you have seen this one: Penn & Teller: The Truth about Bottled Water

Speedskater

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Re: power cord
« Reply #53 on: 8 Dec 2012, 08:17 pm »
In a good ABX test:

a] The listener becomes familiar with both A & B before starting the test.
b] The listener chooses the music or test signals.
c] The listener sets the volume level before starting the test.
d] The listener has control as to how long to listen to each source.  However 4 to 10 seconds seems to be the most sensitive.

werd

Re: power cord
« Reply #54 on: 8 Dec 2012, 08:31 pm »
Hi.
Bingo! You've hit the bull's-eye.

c-J

Bingo! on the Bingo!

Another way of getting around the abx testing deception is by practicing blind testing.  Another useless waste of time but teaching your hearing to adapt to changes on the fly with audio gear would help in passing those stupid tests.

My point is human hearing is a learned perception in audio. You would need some type of superhero bat hearing to ace abx testing with out teaching your self the gear or anything else involved in test before hand.
But the people that know what they are doing won't tell you that since its a scam. Most others that push this are just reading stuff mouthing it back on these boards with no idea of what they are talking about..

JerryLove

Re: power cord
« Reply #55 on: 8 Dec 2012, 08:31 pm »
I agree with SpeedSkater here. ABX massively increases the sensitivity to change. If two things can be told apart with minutes or hours in-between listening: then ABX should be a snap.

It's also worth noting that ABX testing does yield results. Not only do people show a preference between one soda and another, or one speaker and another: but the rate of that preference becomes predictable. Whether we are discussing Dr.Olive and the blind testing done at Harmon Kardon, drug testing (which is control-group; but has much in common), or the blind testing done by Coke and Pepsi. Preferences exist and are consistent across a range of testers.

And there's nothing wrong with testing with your own gear in your own room. The question is "can you tell A from B by sound and which is preferable". Anything which doesn't interfere with that is fair game for a setup.

I most recently did blind ABX testing on gear I'd never heard before in a room I'd never been in before back in October. Level matched speakers (I was part of the level matching myself) with this very cool remote selector. I had zero difficulty telling the speakers apart in ABX: my reliability was 100% (though if I walked out of the room and back in; I often could not determine which was playing).

I liked them so much I actually bought one of the pairs I was ABX testing. They are in my living room now.

Julf

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Re: power cord
« Reply #56 on: 8 Dec 2012, 09:35 pm »
But the people that know what they are doing won't tell you that since its a scam. Most others that push this are just reading stuff mouthing it back on these boards with no idea of what they are talking about..

Indeed - I do feel a bit like a biologist at a creationist convention.

Speedskater

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Re: power cord
« Reply #57 on: 8 Dec 2012, 09:40 pm »
ABX tests are about hearing differences that are much smaller than the difference necessary to have a preference.  If the difference between A and B is large enough to have a preference then an ABX test should be a snap.  Skilled listeners when doing sensitive ABX tests often can't identify just what the difference is.
When the difference is large enough to have a preference, then just use an A,B choice blind test (no X).

James Romeyn

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Re: power cord
« Reply #58 on: 8 Dec 2012, 09:42 pm »
See above for more test parameter details.

Program is a James Taylor live performance (CD), cymbals a bit splashy, lower treble hot but otherwise captures natural live sound very well, huge extremely layered stage and great imaging effects.  (In Trinaural, as mentioned above, there are hundreds of specific, natural, easily pinpointed audience members, each in their own atmosphere, in a stage extending an estimated 75' beyond the front wall.  Chorus is in perfect arc, apparently several feet behind Taylor.)  James Taylor, piano, rhythm section, moderately large background chourus (all or mostly female on this cut).  Even in mono, employing Trinaural center channel program, there are audible stage and image effects.

2' Stan Warren recipe, Marinco IEC and hospital grade plug vs. 6' generic toss-able molded mains

First SW.  About 30 seconds of the song that begins, "Let us turn our hearts today, to Martin Luther King...".  After switching to the molded mains I definitely suspected the stage shrunk in all three dimensions (again, this particular array creates better spatial effects that any speaker I've heard).  But I also suspected there might be better focus.  I definitely suspected that transients and the overall presentation had a new a-musical edge.

Upon switching back to the SW it was clearly no contest.  Stage and image effects multiplied, edginess replaced by an emotional ease, everything integrated into a whole musical event vs. disconnected musical events with the molded mains cable.  I quickly forgot about listening critically and just let in to the music.  I could best describe the molded mains cable as having some of the effects of a cassette deck (minus the wow and flutter). 

Speaking of wow and flutter.  I recently, for the first time, experienced noticeably improved center pitch of notes, especially, for instance in a large symphonic recording, with room treatment improvements.  I was not searching for it, it just appeared. 

I'll ask the wife to do an ABX test later.   

werd

Re: power cord
« Reply #59 on: 8 Dec 2012, 09:52 pm »
Indeed - I do feel a bit like a biologist at a creationist convention.

You may feel like a biologist at a creationist convention. But in reality you are creationist at an atheist convention.