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Furutech NCF Clear Line Review (AC Optimizer)

Rate this product:

  • 1. Waste of money (piggy bank panther)

    Votes: 268 96.4%
  • 2. Not terrible (postman panther)

    Votes: 1 0.4%
  • 3. Fine (happy panther)

    Votes: 2 0.7%
  • 4. Great (golfing panther)

    Votes: 7 2.5%

  • Total voters
    278

linger63

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kombajn

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" such a misguided idea that hooking up a few turns of a wire between a terminal and insulator of the plug does some good, is beyond me."
Actually nothing will surprise me after I seen small bags of rocks that you place on top of wires to "enhance" sound quality. And there are idiots that will buy that stuff.
 

xaviescacs

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After 2 minutes reading I realize how dull ASR is. On this other site everyone is on jest, one joke after the other. It looks real fun!
 
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anphex

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" such a misguided idea that hooking up a few turns of a wire between a terminal and insulator of the plug does some good, is beyond me."
Actually nothing will surprise me after I seen small bags of rocks that you place on top of wires to "enhance" sound quality. And there are idiots that will buy that stuff.
What? Where did you see that?
 

sarumbear

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" such a misguided idea that hooking up a few turns of a wire between a terminal and insulator of the plug does some good, is beyond me."
Actually nothing will surprise me after I seen small bags of rocks that you place on top of wires to "enhance" sound quality. And there are idiots that will buy that stuff.
I remember the “holly water” that improves sound when placed next to a turntable… :D
 

digicidal

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After 2 minutes reading I realize how dull ASR is. On this other site everyone is on jest, one joke after the other. It looks real fun!
Holy crap... anyone that can go more than a couple pages of that should get some kind of award. A random selection of schizophrenic Scientologists would be far more rational than most of the participants. Good laugh though.

OK... I'm off to make some audio tweaks out of toilet paper tubes and glitter... apparently Barnum underestimated the frequency. :)
 

xaviescacs

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Holy crap... anyone that can go more than a couple pages of that should get some kind of award. A random selection of schizophrenic Scientologists would be far more rational than most of the participants. Good laugh though.

OK... I'm off to make some audio tweaks out of toilet paper tubes and glitter... apparently Barnum underestimated the frequency. :)
They are all kidding, or I'm in the wrong universe.
 

JayGilb

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... But did you listen to it...? It says it right there on the product page:



And obviously, you forgot to burn-in :facepalm:


And it even works for video:
View attachment 203981

... incredible ...
That's why Amir needs to test it via a microphone connected to amp -> speakers and perform some frequency sweeps.
It's not going to make an audible difference, but at least he can say that he "listened" to it via scientific measurement and no audible difference was measured.
 

Talisman

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"Glad to hear it made a difference as I'm a fan of Furutech gear to. I have 3 of these in my system and yes they do make a measurable difference. Pricey but the good stuff usually does cost more."


I have abdominal cramps from laughing .... I have to stop opening links to other sites !!!!!
 

Lorenzo74

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This is a review and detailed measurements of the Furutech NCF CLear Line "AC Power Supply Optimizer." I bought it for US $236 from Amazon seller.
View attachment 203945
I expected the device to be the typical AC mains filter but this is not so based on my reading. Company has this interesting notation in its advertising:
View attachment 203946

It seems to be saying that there is nothing between Neutral and Line (Hot) terminals! What is there then? They have a short video that shows the following:
View attachment 203947

There are two air core coils with one lead attached to its corresponding mains terminal. But the other side from what I can tell is just connected to the enclosure of the device itself (???). Here is a more clear shot:
View attachment 203948

Company claims reduction in noise and indeed we read that in a couple of reviews they have posted on product page:

View attachment 203949

View attachment 203950

We can easily measure SNR and noise so it is nice to see that as a point of verification.

I looked everywhere to see if there is any safety regulatory certification and sadly, there is none. No UL. No CE. No CSA. No ETL. Nothing. If the design does tie the hot lead to the case of the device, I would be seriously worried about lack of such certification.

Furutech NCF Clear Line Measurements
I started first by attempting to determine if there is a circuit between the terminals. I could not measure either resistance or inductance between any of the three plug terminals. Using a capacitor meter, I measured just 2 picofarad between hot and neutral which is basically nothing. So it seems my interpretation above is correct: there is no circuit at all between any of the terminals. We could stop here and be done but let's do our usual measurements.

We start with usual measurement of my AC mains, this time with 1 MHz bandwidth given the claims of "high frequency noise:"
View attachment 203951

As usual, my AC power strip provides fairly distorted and noisy AC waveform. I then plugged in the Clear Line in the same power strip and got this:

View attachment 203952

Nothing is changed whatsoever. Even that little glitch in the AC waveform is allowed to pass through unchanged. Let's look at the spectrum of the noise/distortion for better insight:
View attachment 203955

Same outcome.

Next, I ran the Audio Precision APx555 analyzer in its loopback mode to see if the device increases its signal to noise ratio:
View attachment 203958

It does not. Looking at the spectrum of noise, again with 1 MHz bandwidth we get the same outcome:

View attachment 203954

We could keep testing but seeing how there is no impact on the AC power itself, there can't be any in audio device which further filters that input.

NCF Clear Line Listening Tests
I used my everyday setup for listening test: RME ADI-2 DAC powering my Dan Clark Stealth headphone. The Stealth is closed back so nicely isolates the headphone from room noise. I played through my reference tracks while connecting and disconnecting the NCF Clear Line. There was absolutely no difference. This is an easy test because the sound keeps playing so there is no glitch to disturb the testing, or make you forget how something sounded.

Conclusions
Many of the AC filters I have tested have some kind of electrical filter so they do "something." The Clear Line has none according to its manufacturer and my testing. So no wonder that it has no impact on AC signal. And with that waveform unchanged, even if you plugged in a poorly designed audio device, you would not get a difference. How someone can have such a misguided idea that hooking up a few turns of a wire between a terminal and insulator of the plug does some good, is beyond me.

The "nice" thing here is that a blind AB test is trivial to setup. Levels will not need matching and connection/disconnection has no glitch/impact. So anyone who says the sound is improved is highly encouraged to perform such a test and post a video of it.

Needless to say, I cannot in any form or fashion recommend the Furutech NCF Clear Line.

----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
@amirm aren’t you happy?
Also Masamitsu F. And Yoshio O. Are ASR members…
(2 voted for golfing Panther)
Best
 

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sq225917

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Luckily for Furutech, " draws and eliminates resonance" isn't a provable claim, as it means nothing. So they've broken no laws.

But it's a 100% bullshit product
 

anphex

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I want any person that claims it has noisy AC and it "needs" filters to improve the signal show me picture a of their TV or monitor display where the pixel noise is visible DUE to the noisy and distorted AC coming in. And then, if there isn't any noise whatsoever I want them to explain to my why a display isn't prone to AC noise but audio devices are.

And then I sit back and watch their head explode.
 

Jarrett

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@amirm on this topic sort of, what do you actually recommend a stereo system be plugged into? Wall outlet? Power strip? Surge protector? Something else? Would be interesting if you one day measured an amplifier's performance through all three.
 

anphex

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@amirm on this topic sort of, what do you actually recommend a stereo system be plugged into? Wall outlet? Power strip? Surge protector? Something else? Would be interesting if you one day measured an amplifier's performance through all three.
He basically did already considering all AC, AC regenerator and other AC gadgets tests. All of them with the same result:
It doesn't matter. At all. If you've got working electricity in your home and a plug you're good to go.
 
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