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Old 12th November 2003, 05:49 PM   #101
Rob M is offline Rob M  United States
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Default Re: Re: Re: Interpreting results

Quote:
Originally posted by Kuei Yang Wang

Clearly not so. You again willfully omit all qualifications written.
Jeez. Have you had your blood pressure checked lately?

Okay, I'll try one more time. I, ignorant worm that I am, unworthy to lick the mud off your statistical boots, beseech thee: after hours of studying your godlike communications, attempting to extract the crystalline wisdom they contain, have, due to my severely limited intelligence, come to the no doubt erroneous conclusion that you are saying that there are some audible differences that, while real, are too small to be reliably detected using double blind ABX testing without gigantic samples. In the depths of my ignorance, I believe that such a thing could be true in principle, but my comprehensive impotency prevents me from knowing what those differences might be or exactly how small they are. I beg, I pray, enlighten me! I will remain in fasting and meditation until you deign to make my life whole with this knowledge.



Joi gin.
 
Old 13th November 2003, 02:46 PM   #102
sully is offline sully  United States
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This is the exact reason I have lamented FOCUS (actually, lack thereof)..

Please, I started this thread hoping that some would discuss the E/M theory and test aspects concerning the topic..

It is much easier discussing actual measurements and S/N ratio of unwanted signals generated in the equipment.

Statistical analysis of an entity that is horribly undefined, and poorly controlled, is utterly useless..

How in the name of Sam Hill do you perform a cable swap if the geometry of the cable (size, conductor twist pitch, insulation thicknes, bends, spatial positioning) are not rigidly controlled but possible input variables??

My discussion is towards determining what if any, of these factors play in the hypothesized effect..

If anybody (including the warring parties here) has any valid test data to bring to the table, then I would certainly entertain discussion of audibility testing..

Till then...please keep on topic..

Cheers, John
 
Old 13th November 2003, 03:11 PM   #103
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Quote:
Originally posted by sully


What I find most interesting is that the coupled flux induced currents will occur regardless of the thickness of the wires..you can use #2 welding wire for all the power and ground connections..but that loop voltage will still happen..
Yes; the open-loop voltage is purely a function of the loop's geometry. However, when you close the loop, what parts of that voltage appear where will depend, for instance, on the resistances of the various parts of the loop (i.e. the power cords, plugs and signal interconnects).

Earth loops are insidious for just the reasons you pointed out - simply moving the wires will change the problem. I strongly suspect a lot of power cord / interconnect mystique has arisen because people actually have grounding problems of some sort; changing the wires is merely a palliative and does nothing to correct the underlying problems.

Cheers
IH
 
Old 13th November 2003, 03:23 PM   #104
sully is offline sully  United States
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Quote:
Originally posted by IanHarvey


Yes; the open-loop voltage is purely a function of the loop's geometry. However, when you close the loop, what parts of that voltage appear where will depend, for instance, on the resistances of the various parts of the loop (i.e. the power cords, plugs and signal interconnects).

Earth loops are insidious for just the reasons you pointed out - simply moving the wires will change the problem. I strongly suspect a lot of power cord / interconnect mystique has arisen because people actually have grounding problems of some sort; changing the wires is merely a palliative and does nothing to correct the underlying problems.

Cheers
IH
Hmmm...you've been perusing AR, I see..I posted that actual point there (least I think it was there) about a month or two ago.. (oh, btw..I'm jneutron there)

The loop voltage of the shield that presents across the amp input will truly be a function of the total loop resistance, and how much of it is the shield of the IC..

The loop voltage of the center conductor will be the loop voltage, as the center conductor total loop resistance will be the amp input resistance..that is the loop resistance, +/- about .01% (I'm giving 1 ohm for the rest of the wiring..so it's 1 part out of 10K.)


Second part: total agreement..a lot can be learned from the pro apps..there, they use balanced for elimination of this type of problem.

Cheers, John
 
Old 10th November 2013, 02:02 AM   #105
JRA is offline JRA  United States
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I hope you guys figured out that power cords are snake-oil. To cut to the chase you had better think of "treating" every single foot of the in-wall AC wiring back to your breaker box, then to the utility "pole", then to the sub-station, etc.

Trying to treat that last 6 feet from your outlet to your gear with shielding, exotic metals and materials is silliness. Think about it. The only way to possibly block RF riding on all conductors of a power cord is to clamp a snap-on ferrite bead around it at the entry to your equipment. That's it. I'm sorry. You've seen these before. They are the "lumps" that have to be placed around cables of all kinds or that equipment won't pass international standards for Electo-Magnetic Compatibility (EMC). You fail in the lab - you go home. You can't sell that product. You are done. The quick fix in the lab is a ferrite. Ferrite material eats RF.
 
Old 10th November 2013, 06:41 PM   #106
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Agree with you, JRA.

Quote:
Originally Posted by m.parigi View Post
I thought I'd personally heard a lot of improvements when changing or switching power cables...
Too bad that when it wasn't me doing the changing I wasn't able to tell if anything had changed.
....
....
The human mind is a very powerful generator of illusions...
Still true.

There are some exceptions though. If you have some badly filtered digital equipment
or turntable motor drive (like Linn's Lingo I) there may appear some HF rubbish on the
mains. Nevertheless any snake oil cord won't help at all, but some ferrite filter may do.
__________________
thanks
Blaue Leuchtdioden machen blöd. (hb)
sent from NSA monitored device
 
Old 10th November 2013, 11:42 PM   #107
JRA is offline JRA  United States
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Thanks TickTock. If I posted this elsewhere, or in the past, I'd be in flames.

So yes, a power conditioner with multiple outlets is a good way to go. That box will stop or severely attenuate all the upstream RF garbage delivered to your power receptacle. The buck stops there. It should offer line-to-line and lines to green ground low impedance RF paths (capacitors). Same thing re lightning protection components - usually MOV varistors but other products also add gas tubes in parallel. To me that mix is the best. The MOV is fast and catches the spike's rising edge by flattening it but there is still significant follow-on energy. The gas tube is slower but when it wakes up it "crowbars". Crowbar means that it collapses the spike, shorts all the remaining transient energy threw itself, continues to do that brute-force job until the threat voltage is gone and then lets go. Two different jobs - two devices. Division of labor.

Another feature to look for is a maximum current rating on the conditioner which may seem low. Why wouldn't it be say, 15A or 20A? Why 12A? That can tell you that there is "in-line" protection like ferrites or chokes. That part absorbs conducted broadband RF riding on the copper and turns it into heat - just a little heat. It does that all day long just like that lump in the data or power cord. The odd current restriction is maybe b/c there are magnetic devices in series with your wall receptacle lines and its own outlets. Those may have "saturation" limits where they can't do their job if the constant equipment load current is high and usually seen on isolation transformer-based conditioners or inline inductor / choke-based conditioners. That's why I mention this.
 
Old 11th November 2013, 04:10 AM   #108
KBK is offline KBK  Canada
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The ear hears via transient positive leading edge peak function. it adds them up in time and level and works with harmonic systems thereof and is capable of an easy 100,000th of a second accuracy, in one spec area alone. It is better than that in multiple ways and areas. Plus the big *** organic computer attached to it.

Each of us has different wiring and different ears, and have learned differently.

In effect, some can't hear for fecal matter and some of us are highly trained.

And the two shall never meet.


If you look at what I said about how the ear works and then look at what happens to the fundamental of the complex dynamics of a power cord and the equipment, as an integrated system...when the equipment (DUT) is under draw complex draw situations..then it is clear that yes, a power cord can easily be heard to make a difference.

This is most easily discerned in systems that use traditional rectified AC power, due to the straightforward dynamic connectivity of the DC rails to the AC power.

If you can't hear it, then you are not capable of this feat of hearing, do not know what you are doing, do not possess the skills to discern this, or cannot hear it.

It's not a sin to be incapable of figuring out the connection between the ear and the electrical situation, or not being able to hear it.

But it is ignorant and childish to slam those who can observe and elucidate the differences and the why of their existence. It's a question of learned skills, innate hearing capacity, and then figuring out the why of the situation.

In some cases, this about keeping this understanding private, so that it can be used to produce product for buyers. the buyers have that innate hearing capacity and they have taught themselves to hear these differences.

I myself can easily hear the differences that different 'high end' power cords produce, but I myself don't bother to play with or use them.

To aid in the understanding, again.. I'm in the area of hearing capacity, and associated learning... of something akin to a Usain Bolt, or an Aryton Senna. So are others. Many others. Training plays quite strongly into it.

~~~~~~~~~
Not everyone has that skill, and that innate capacity. I will not tolerate being called crap for being capable in that way, by blowhards who are not.

Last edited by KBK; 11th November 2013 at 04:18 AM.
 
Old 11th November 2013, 04:27 AM   #109
KBK is offline KBK  Canada
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Remember:

To argue that someone else cannot possibly hear such vanishing levels of distortion is the exact same thing as arguing that all people on the planet must be of exactly the same mental design, exactly the same wiring and exactly the same intelligence/IQ as all others, but coming from an ego standpoint of all others must be as you.

And that, is categorically insane.
 
Old 11th November 2013, 08:57 AM   #110
marce is offline marce  United Kingdom
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Quote:
Originally Posted by KBK View Post
The ear hears via transient positive leading edge peak function. it adds them up in time and level and works with harmonic systems thereof and is capable of an easy 100,000th of a second accuracy, in one spec area alone. It is better than that in multiple ways and areas. Plus the big *** organic computer attached to it.

Each of us has different wiring and different ears, and have learned differently.

In effect, some can't hear for fecal matter and some of us are highly trained.

And the two shall never meet.


If you look at what I said about how the ear works and then look at what happens to the fundamental of the complex dynamics of a power cord and the equipment, as an integrated system...when the equipment (DUT) is under draw complex draw situations..then it is clear that yes, a power cord can easily be heard to make a difference.

This is most easily discerned in systems that use traditional rectified AC power, due to the straightforward dynamic connectivity of the DC rails to the AC power.

If you can't hear it, then you are not capable of this feat of hearing, do not know what you are doing, do not possess the skills to discern this, or cannot hear it.

It's not a sin to be incapable of figuring out the connection between the ear and the electrical situation, or not being able to hear it.

But it is ignorant and childish to slam those who can observe and elucidate the differences and the why of their existence. It's a question of learned skills, innate hearing capacity, and then figuring out the why of the situation.

In some cases, this about keeping this understanding private, so that it can be used to produce product for buyers. the buyers have that innate hearing capacity and they have taught themselves to hear these differences.

I myself can easily hear the differences that different 'high end' power cords produce, but I myself don't bother to play with or use them.

To aid in the understanding, again.. I'm in the area of hearing capacity, and associated learning... of something akin to a Usain Bolt, or an Aryton Senna. So are others. Many others. Training plays quite strongly into it.

~~~~~~~~~
Not everyone has that skill, and that innate capacity. I will not tolerate being called crap for being capable in that way, by blowhards who are not.
Yeh wotever
 

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