Furutech NCF Clear Line Review (AC Optimizer)

[Nango]

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

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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:"
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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:

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

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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.

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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/

No safety certification is indeed a no-go.

 

[Nango]

What makes it even worse, for this much, one might buy something that really works a bit...

Furman AC-210 A E Power Conditioner

Compact Power Conditioner 10 A (2300 Watt max.), For video and audio applications, Technology from the PL series, LiFT offers linear AC power filtering to ensure clean power for unequaled audio & video clarity, Transient voltage surge suppressor,...

www.thomann.de

know

What makes it even worse, for this much, one might buy something that really works a bit...

Furman AC-210 A E Power Conditioner

Compact Power Conditioner 10 A (2300 Watt max.), For video and audio applications, Technology from the PL series, LiFT offers linear AC power filtering to ensure clean power for unequaled audio & video clarity, Transient voltage surge suppressor,...

www.thomann.de

I know people who recabled the Furman with silver cables, that rocks!!!, they reported.

 

[Johannes AU]

That "coil" looks like a thread repair insert ....

 

[Triliza]

And there I was feeling bad that my little knowledge of electronics wasn't enough to understand what the heck is this thing supposed to do, it turns outs it does nothing at all (once again). From 6moons:

"That's today's seasoning tweak from Furutech. Inside its carbon-lined nylon/fiberglass barrel which terminates in rhodium-plated Schuko or US/Nema blades, there's NanoCrystal². That's Furutech's trade name for a special powdered crystalline substance combined with ceramic particles and carbon powder to "generate negative ions, convert thermal energies to infrared and create mechanical/electrical piezo-effect damping". The final assembly of this parallel AC optimizer which also contains small enameled air-core inductors undergoes a 2-stage cryo and demag treatment which Furutech call Alpha Process."

That is rocket science for me, called me impressed. Based on the audiophiles reviewers out there, obviously for best results you need to have two or even better three of these on your system. And of course to plug them on Furutech $3000 power strip. Being made in Japan though, it may do nothing, but hopefully it'll last for a lifetime.

 

[nyxnyxnyx]

Is this product actually a bigger "f*ck you" to the uninformed consumers? I mean there's seemingly *nothing* inside it. Other accessory-class products at least put up with more components.
I'd be a little bit salty if I bought it and found out it is just.... a thing.

 

[JSmith]

And of course to plug them on Furutech $3000 power strip.

Of course;

This product just seems like lunacy;

https://www.furutech.com/images/2020/08/HFC_478_Furutech_NCF-Clear-Line_Reprint_half.pdf

Furutech Clear Line: Mfr. admits it does nothing, audiophools buy it anyway! - Page 1

Furutech Clear Line: Mfr. admits it does nothing, audiophools buy it anyway! - Page 1

www.eevblog.com

JSmith

 

[naviivan]

could of at least gave a larger coil for that price!

 

[respice finem]

I know people who recabled the Furman with silver cables, that rocks!!!, they reported.

The one linked solved my (probably outside) interference problem, so I wouldn't say these things all do nothing. There might be a reason why studios are using similar (probably more advanced) stuff. Only because many such devices are "snake oil", doesn't mean all must be.

Being firmly in the "objectivist camp", and not expecting "better sound", I wouldn't buy the Furman if I wouldn't have a problem, but I had one, and now it's gone.

PS Audio P12 Review Part 2: Power Testing

How is this even possible? I thought those conditioners are - according to what I learned here - pure snake oil? As a non-engineer, I can only say the little Furman worked for me in this particular case.

www.audiosciencereview.com

 

[Ra1zel]

What is the tought process of people who buy this kind of things, I must know.

 

[sarumbear]

What is the tought process of people who buy this kind of things, I must know.

We should ask the person people who voted as great

 

[respice finem]

What is the tought process of people who buy this kind of things, I must know.

sometimes, see above. But, alas, the most will believe what they're told by advertisement, because they lack knowledge. Been there, done that...

 

[respice finem]

We should ask the person who voted as great

Probably the seller

 

[voodooless]

What is the tought process of people who buy this kind of things, I must know.

For your own sanity, I'd recommend against finding out...

 

[DSJR]

This micro-crystal or whatever reminds me of 'glass loaded black plastic' which reminds me of the material Philips used to use to make plastic parts in their video deck mechanisms (noisy and strong, but brittle too the way they used it. is the 'carbon' giving the colour? Not a materials analyst so guessing...

 

[Count Arthur]

OK, which one of you voted "Great"?

I wan't you to stand in the corner and think about what you've just done.

 

[DavidMcRoy]

it’s just like voodoo: the magic only works if you believe in it.

 

[Aperiodic]

Expectation bias and outright fraud dominate today's audio market.

 

[CedarX]

From their product page…. Obviously. Amir got a counterfeit and that’s why it showed no audio improvement!
Oh and if Amazon US is not an authorized Furutech dealer, there is no warranty (don’t know what could go wrong with the thing: maybe it starts doing something?), so who sells the product is important.
The only thing missing in the product page is to indicate that who uses the product is critical..!!!

Quote from A Call for Humor thread: “Scientists say the universe is made up of protons, neutrons and electrons. They forgot to mention morons…”

 

[Mart68]

Gives them plausible deniability for when third-party testing shows their devices do nothing.

 

[anphex]

Products like these make me realize that me wanting a 3000 $ massage chair may not be that an unreasonable and wasteful idea.