• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

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

Nango

Major Contributor
Joined
Aug 6, 2018
Messages
1,463
Likes
985
Location
D:\EU\GER\Rheinhessen
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/
No safety certification is indeed a no-go.
 

Nango

Major Contributor
Joined
Aug 6, 2018
Messages
1,463
Likes
985
Location
D:\EU\GER\Rheinhessen
What makes it even worse, for this much, one might buy something that really works a bit...
know

What makes it even worse, for this much, one might buy something that really works a bit...
I know people who recabled the Furman with silver cables, that rocks!!!, they reported.
 

Triliza

Senior Member
Forum Donor
Joined
Jun 23, 2021
Messages
477
Likes
558
Location
Europe
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

Addicted to Fun and Learning
Joined
May 22, 2019
Messages
506
Likes
474
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

Master Contributor
Joined
Feb 8, 2021
Messages
5,152
Likes
13,211
Location
Algol Perseus
And of course to plug them on Furutech $3000 power strip.
Of course;

1651485974724.png


This product just seems like lunacy;

1651486065180.png


1651486103827.png





JSmith
 

respice finem

Major Contributor
Joined
Feb 1, 2021
Messages
1,867
Likes
3,774
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.
 
Last edited:

Ra1zel

Addicted to Fun and Learning
Joined
Jul 6, 2021
Messages
531
Likes
1,048
Location
Poland
What is the tought process of people who buy this kind of things, I must know.
 

sarumbear

Master Contributor
Forum Donor
Joined
Aug 15, 2020
Messages
7,604
Likes
7,313
Location
UK
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 :)
 
Last edited:

respice finem

Major Contributor
Joined
Feb 1, 2021
Messages
1,867
Likes
3,774
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...
 

DSJR

Major Contributor
Joined
Jan 27, 2020
Messages
3,312
Likes
4,425
Location
Suffolk Coastal, UK
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...
 

CedarX

Senior Member
Forum Donor
Joined
Jul 1, 2021
Messages
407
Likes
617
Location
USA
2F0DFFB6-D538-4E40-B0C5-0B57FC34CA14.jpeg
From their product page…. Obviously. Amir got a counterfeit and that’s why it showed no audio improvement! :p
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

Major Contributor
Forum Donor
Joined
Mar 22, 2021
Messages
2,605
Likes
4,854
Location
England
Gives them plausible deniability for when third-party testing shows their devices do nothing.
 

anphex

Addicted to Fun and Learning
Forum Donor
Joined
May 14, 2021
Messages
662
Likes
870
Location
Berlin, Germany
Products like these make me realize that me wanting a 3000 $ massage chair may not be that an unreasonable and wasteful idea. :D
 
Top Bottom