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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

voodooless

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They’re so convinced of it working, I almost start to wonder myself: is there something magical going on in this device that actually does something?
They could not have water a lot of time posting and organized a proper controlled double blind test to prove their point. With a DUT like this, it should be super easy!
 

anphex

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@all

Please don't feed Quadlabet and move on.
 

Spkrdctr

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Well, I'm new to this forum and I just puchased the Furutech Clear Line and have had it for a couple of days and think it's absolutely fantastic. Yes, I am willing to take a double blind test to see if I could tell if it was in the system or not. Gosh it would be so easy tell. No, I'm not a technical person. I let my aged ears tell me what's going on. And my ears say that this is a fantastic product. Why don't at least one of you give it a listen. You might by surprised at what you hear.
I assume all of you guy hate tube/valve amplifiers? Am I right? Yes, I probaby am. They don't measure, correctly. And how could something that dosen't have the specs be any good? The distortion levels are too high. Blah, blah, blah.
OK, I took you up on the challenge. I also heard amazing things happening. I heard airy highs, smooth chocolaty mids, Deep accurate bass, fast but not too fast. I also without even listening that hard heard veils being lifted. I am absolutely stunned at how it made my cheap 15 year old Sanyo boom box sound. Totally amazing!
 

ahofer

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Yes, I am willing to take a double blind test to see if I could tell if it was in the system or not.
(standard language below)
Welcome to ASR! You've made an unsupported assertion or a scientifically implausible claim that will cause most people in this science-oriented forum to react with skepticism (or scepticism if they are in the U.K.). Please don't take the reactions as overtly hostile - most of us are just frustrated with the many newcomers who have clearly come here just to "troll". Please do engage with the membership to find an objective, controlled method to support or discard your hypothesis. Our membership includes recovering subjectivists, many engineers/scientists, and several famous figures in the world of audio engineering research. Generally, they can cite scientific, controlled research to support their views. Most believe in the fallibility of human sighted judgement, and think blind testing and measurements are critical ingredients for assessing equipment contributions to sound quality. We'd love to have you, but if all you want is a) to fight or b) to have others cheerlead for your subjective views or anecdotal evidence, I'd suggest you will be happier elsewhere.

How do you propose to run your blind test?

(also see my signature quotes)
 

AdamG

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OK, I took you up on the challenge. I also heard amazing things happening. I heard airy highs, smooth chocolaty mids, Deep accurate bass, fast but not too fast. I also without even listening that hard heard veils being lifted. I am absolutely stunned at how it made my cheap 15 year old Sanyo boom box sound. Totally amazing!
(standard language below)


How do you propose to run your blind test?

(also see my signature quotes)
Don’t wait too long for an answer now……;)
 

pseudoid

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NormB

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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.

Edit: video review also posted:


----------
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/


I’m new at this “audiophile” game. Sort of. Sold over a thousand LP’s in 1984 after a divorce and CD’s were “sound clear as light”. In the past 3 years I’ve collected nearly 1,000 LPs already and have gone through several cartridges, blah blah blah.

When a post comes up on something like this here or elsewhere, it puzzles me why certain very verbose fanatics choose to shout me down rather than answer simple questions.

Over on Audiogon, there’s this “new” gadget, goes by the name of “Puron” which seems awfully similar to the Furutech gadget here, and a host of others reviewed elsewhere, but not as thoroughly as here, by Amir.

From several reviews on Youtube (blind comparisons) and some EMF/magnetic detection gear, I’m lead to believe there MIGHT be some value here in reducing magnetic induction resulting in auditorily detectable improvements, as people claim,

Maybe. I’ve been a ham radio operator (extra) for a while, I’ve used magnetic loop antennae to good effect so I know a little about electro-magnetic energy.

But the intense, overt, HATE, scorn, derision, absolute trolling/blasting me for just ASKING is blowing me away.

I’ve been called a cultist as I referenced THIS review, when the response from some of “the girls” over there is nothing short of pure cult fanatic following. I’m pretty sure a couple of ‘em are still foaming at the mouth breathing.


I posted this today:

My bad, folks.

I was under the impression that audiophiles were on the main seekers of actual, verifiable, quantifiable, information. Yes, yes, “how it SOUNDS” is ultimately the goal here - but hearing is so different for so many people. Reading reviews and commentary on XYZ speakers, or amps, or DAC’s or phone cartridges teaches us this in every post.

Imagine my surprise at the overt hostility presented upon asking basic questions about gadgetry.

1 - what does it do?

2- how does it do it?

3- how well does it do it?

4- compared to what?

5- Is this effect uniform, reproducible, cost-effective?

Apparently these questions fly in the face of the fanaticism present in a small percentage of very vocal defenders of the faith.

But I’ve been on the innerwebs long enough to realize there are enough self-absorbed, aspergerish kids who can’t converse on par with a civilized world and maintain without acting out.

I’ll keep asking the questions, you do you.

*******

Yeah, that WAS a little catty, I’ll admit, but, dayum.

Might be worth buying just to return it within 30 days if it doesn’t do what it purports to do.


Thanks, though, for your reviews, at least there’s some actual science here, not the scientism and elitist snobbery I’m seeing expressed elsewhere.

This is, by the way, mostly rhetorical.
 

highstream

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For those with decent audiophile level speaker systems, the Clear Line does what’s claimed: obviously better focus, clarity, wider soundstage and noticeably quieter background. All of those improvements are not subtle and in my case because I picked a used one were noticeable in short order (I can’t speak to burn in). However, for those who like a degree of warmth vs. “neutral,” the Clear Line drains it, or at least it did to my system, leaving an emotionally sterile sound to my ears.
 

ahofer

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For those with decent audiophile level speaker systems, the Clear Line does what’s claimed: obviously better focus, clarity, wider soundstage and noticeably quieter background. All of those improvements are not subtle and in my case because I picked a used one were noticeable in short order (I can’t speak to burn in). However, for those who like a degree of warmth vs. “neutral,” the Clear Line drains it, or at least it did to my system, leaving an emotionally sterile sound to my ears.
We see these implausible claims often enough that I have a canned response:

Welcome to ASR. You've made an unsupported and/ or implausible assertion that most people in this science-oriented forum will regard with skepticism. Please don't take the reactions as overtly hostile. Please do engage with the membership to find an objective, controlled method to support or discard your hypothesis. We'd love to have you, but if all you want is a) to fight or b) to have others cheerlead for your subjective views, I'd suggest you get out now.
Also, see my signature quotes.
 

highstream

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My post is for people who judge with their ears and that come across this forum as a result of a search for reviews.
 

dshreter

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Well at least the manufacturer has adopted truth in advertising when they selected their name:

 

kongwee

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Can someone take the sound samples and do a null test on them?
Actually in my iMac I heard the difference. Is it really matter? I did it in his previous clip. Reference sets are hard to null. Sound will pass through. You can still heard the difference in null. The test sets will have more sound pass through against the reference.
 

BDWoody

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For those with decent audiophile level speaker systems, the Clear Line does what’s claimed: obviously better focus, clarity, wider soundstage and noticeably quieter background.

Uh huh.

My post is for people who judge with their ears and that come across this forum as a result of a search for reviews.

How thoughtful. Thing is, most come here to avoid the endless claims based on uncontrolled subjective impressions.

Hopefully you'll stick around and learn why we feel comfortable taking this approach.
 

Purité Audio

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The problem is none of us here ( apart from Matt Hooper ) have ‘decent audiophile level speaker systems.’
For this New Year we should all pull our socks up.
Happy New Year all you mid-fi ASRer’s.
Keith
 

antcollinet

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obviously better......

In fact, "obviously" for an item that literally has nothing built in that can filter anything : absolutely no effect whatsoever.

It is literally in the same range of products as magic rocks and crystals.
 
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ahofer

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My post is for people who judge with their ears and that come across this forum as a result of a search for reviews.
People who only judge with their ears have lots of other places to go for subjective impressions. You came here to stand up for or rationalize your purchase and/or your “golden ears”.

 
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