Interesting article on cables...drama ensues...

Great article. In the rare power cable thread that is not in The Cutting Edge forum, I've crossed swords with the retail guys and yes, there are many here at good ole AK. They refused to answer simple science questions and eventually began to circle their wagons as if they were under attack. Then they resorted to ganging up and behaved in a manner I perceived to be thuggish. One of them even sent me private messages attempting to explain himself to which I replied that he is industry advocate through and through who is cloaking himself as an enthusiast. The article is an excellent example of industry protection except the shills are cloaking themselves as an audio society, which is even worse.

EDIT ADD: In the interest of balance, I do not feel this way about speaker cables and interconnects, both of which are in the signal path. Power cables are not in the signal path and therefore are open to question.
 
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As to the cables I have no opinion. As to the letters and the fact he prints the letters out in public makes me think he is more interested in controversy than the truth of the cables.

I am sure the rest of the members of the society can make educated choices about what power cables they like, and they don't need Marks testing to make that choice.

In before the lock!
 
EDIT ADD:...Power cables are not in the signal path and therefore are open to question.

An audio circuit designer might feel differently. The output of the power supply is directly sent to the output. The audio input level modulates that signal coming from the power supply.

No power supply, unfortunately, is a perfect filter. In additional there is cross coupling and radiated signal from the incoming power side. Noise generated in the power supply rectification stage is also poorly coupled right back onto the power side, creating potential to couple back into other devices. And that's all while we're referring to a linear power supply....before we go to the tremendously high noise of the typical switch mode power supply noise generator.

It's not all as simple as the thinking the power supply is somehow removed from what comes out of a device on the audio port.

EV3
 
An audio circuit designer might feel differently. The output of the power supply is directly sent to the output. The audio input level modulates that signal coming from the power supply.

No power supply, unfortunately, is a perfect filter. In additional there is cross coupling and radiated signal from the incoming power side. Noise generated in the power supply rectification stage is also poorly coupled right back onto the power side, creating potential to couple back into other devices. And that's all while we're referring to a linear power supply....before we go to the tremendously high noise of the typical switch mode power supply noise generator.

It's not all as simple as the thinking the power supply is somehow removed from what comes out of a device on the audio port.

EV3

Sigh, I'll keep it short. AC power is 120V AND 60 Hz so it is immensely dirty for audio use. Bridge rectifier converts AC to DC for use in the rails to which signal is injected. This is a gross oversimplification. The dividing point is the bridge rectifier which is intended to block AC. The power cable is before the bridge rectifier and before signal is introduced and so is not in the signal path. Believe me, no retailer could explain this nor could any of them tell me how power cables affect DC. You are welcome to try and I will of course consider your answer.
 
Sigh, I'll keep it short. AC power is 120V AND 60 Hz so it is immensely dirty for audio use. Bridge rectifier converts AC to DC for use in the rails to which signal is injected. This is a gross oversimplification. The dividing point is the bridge rectifier which is intended to block AC.
No, a rectifier simply passes current in one direction, so AC becomes DC. If it's noisy AC before a rectifier diode, it's noisy DC after it. It's the filter capacitors after the rectifier smooth out both line-frequency ripple and relatively high frequency transients, leaving clean DC.

The power transformer is better RFI filter than the rectifier diodes. Any noise above around 100khz (typically, and very roughly) that comes in via the transformer primary will generally not make it to the secondary. However, RFI that comes in via the power cord can be rebroadcast, antenna-like, into the interior of the typically-unshielded consumer gear and picked up by sensitive audio circuits.

Also, the audio signal isn't injected into the power rails. An amplifier modulates the current flow from power rails to the speaker.
 
Frankly, we are not discussing the merits of proper Power supply design, filter caps, etc.

The discussion is whether replacing one Power supply CORD with another Power supply CORD can result in substantial improvements
in the overall audio quality. Its about an extremely expensive Power cord that feeds the actual power supply, not the power supply itself.

As mentioned, the Power supply Cord is the INPUT to the power supply, not the Output.
It is outside the Signal Path!

If you want to make a valid change, put money into an AC line filter for your system,
not a new power cord.



An audio circuit designer might feel differently. The output of the power supply is directly sent to the output. The audio input level modulates that signal coming from the power supply.

No power supply, unfortunately, is a perfect filter. In additional there is cross coupling and radiated signal from the incoming power side. Noise generated in the power supply rectification stage is also poorly coupled right back onto the power side, creating potential to couple back into other devices. And that's all while we're referring to a linear power supply....before we go to the tremendously high noise of the typical switch mode power supply noise generator.

It's not all as simple as the thinking the power supply is somehow removed from what comes out of a device on the audio port.

EV3
 
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It's certainly true that the audible benefits of aftermarket power cords and other power conditioning strategies is not increasing output by 2 db!

Completely agree there - and THAT was the point of the original linked article, and this discussion.

Noise reduction due to high end power cables is something else. A well built (and well shielded) preamplifier should not be capable of significant levels of ingress.

If you want high end power supply cables, go ahead and buy them,
BUT - THAT argument does not belong in THIS THREAD.
 
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we could always just nut up some 12-2wg romex from the box to the transformer mains and end the debate? coincidently, I have 12-2wg romex and wire nuts in stock as part of my remod so lets have at it!

ps: it is a transformer and the cool thing about them is any noise on the primary gets reduced at the same ratio as the noise known as the poco product itself, and any rfi noise will be above the operating capacity in Mhz of the unit anyways.

I find that rfi noise is able to be introduced on or near EC caps on the sensitive side of tonal/phono amps. and usually a faraday cage known as 'the case' takes care of that.
 
The first real component the power cord feeds is the transformer. They have certain characteristics.
Special transformers are used in the output sections of tube amps and the better ones can do 20 to 20K hertzs with no or very little loss. They are of a specific design to allow the higher frequency's to work properly and not be lost in the iron.
Since the first component in an amp or just about any other piece of gear is a transformer specifically designed for 60 or 50 hertz, most of the hash on the line is filtered out as losses in the iron. They are not very effective at letting through all the high frequency noise that may be found on the incoming power. The rest of the power supply cleans up almost all of it.
If the power cord is sized to the load properly that a bigger cord should make no difference.
My Mac MC40's still sport the factory lamp style cords, I do believe that the engineers at McIntosh Laboratories knew a thing or two.

BillWojo
 
No DaveV, the claimed 2DB increase in GAIN mentioned in the original post is a substantial difference,
and cannot exist from a change in power supply cord. There is no gain in a straight piece of wire. The laws of physics do not change.

The rest of your comments are a different argument and have no place in this narrow discussion.
Again, I remind you gently that we are not discussing the merits of proper Power supply design, filter caps, etc.

This thread is not open for the typical high-end Power cable argument highjacking.
Stay on topic or leave this thread.
 
Again, this thread is about a blogger posting a disgreement with a claimed 2DB improvement in gain by using a high end power cord.

Its not about noise reduction from Power supply cords, perceived or otherwise.
Those discussions go to The Cutting Edge threads. Argue your opinions there, not here.

I will continue to delete thread posts that go to endless argument territory, or I'll get another mod to lock this up.
 
No DaveV, the claimed 2DB increase in GAIN mentioned in the original post is a substantial difference,
and cannot exist from a change in power supply cord. There is no gain in a straight piece of wire. The laws of physics do not change.
That's exactly what I wrote. The only way a change in power supply cord could result in an apparent gain is if there's an actual loss in the original cord; e.g., the original power cord is a resistor.
The rest of your comments are a different argument and have no place in this narrow discussion.
Again, I remind you gently that we are not discussing the merits of proper Power supply design, filter caps, etc.

This thread is not open for the typical high-end Power cable argument highjacking.
Stay on topic or leave this thread.
Sorry, but I think you misunderstood what I wrote.
 
That's exactly what I wrote. The only way a change in power supply cord could result in an apparent gain is if there's an actual loss in the original cord; e.g., the original power cord is a resistor.

Sorry, but I think you misunderstood what I wrote.

No, I agreed with the one point - there is no GAIN in a piece of straight wire.


The rest of your post was not relevant to this thread, and so No, I did not misunderstand.
I won't argue off-topic further -
 
I thought from reading the original post and the link that the real intent of this thread had nothing to do with power cords but more about the member of the Audio Society that disagreed with a manufacture presenting some products that he felt were not honestly presented and the President of the Society not likeing that he made such info public.

So the real intent of the thread is not about the merits of power cables, but do members of an audio Society have the right to disagree with some of the presenters (manufactors) and publish their findings without being victimized by the society administrator. Or if you belong to an organization and they have rules does the administrator have the final say if their is a disagreement in policy.
 
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Yep, until qdrone starting arguing cable value in post 47 - trying to change it to another
interconnect discussion.
 
Is there an aspect of life which doesn't contain some form of drama? Power cords of all things, the most boring part of any system, about as interesting to discuss as the installation of a toilet repair kit, yet it's managed to become dramatic.

One thing I haven't seen mentioned, is that 2dB is a very tiny change in SPL. I wouldn't count on the author's test equipment being set up well enough to resolve this change.. maybe he moved a bit while the cord was changed, maybe other people in the room moved and it affected the room acoustics in a way which changed the level by 2dB, maybe some ambient noise affected the reading, like HVAC switching on or off, maybe his meter just isn't that accurate to begin with.

There's no positive proof the power cord vendor did anything wrong, I can see why the host of the show didn't like his "expose". Regardless of the merit of expensive power cords, any sort of scientific test which doesn't strictly control all variables except the one being tested, is not valid and shouldn't be presented as such. Especially to be used as proof of someone's dishonesty. This is elementary school science.. controlled variables versus the independent variables.
 
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