My experience with Furutech NCF Clear Line in Naim system

I wanted to purchase this “tweak” accessory for my Naim 252 / Supercap / NDS / 555PSDR / 300 system.

It is a product of the Japanese Furutek of which I do not esteem being a serious company in my opinion.

It still has a few hours of use.

The product is inserted in a free plug in the same power strip where the other electronics are connected or before the mains air conditioner / regenerator.

It’s incredible but the insertion or not of the device changes the sound and is immediately true.
The product makes the sound more defined, really “clearer” as if it were “drawn” with more clarity and a veil of noise had been removed around it.

It is as if there were more treble even if it makes the mids less mid-range I don’t know how to explain it, as if there were more clarity, an effect similar to the “clear voice” function in televisions.

This effect may still be temporary because the product has just arrived at my house and I am testing it.

But absolutely the device changes the sound, it is crazy that by simply acting from the outside of the electronics at the current level, inserting this passive element changes the characteristics of the sound.

But I don’t know if I like this “clear voice” effect more or not.

For this reason, now I have it burned in for a couple of days, then I test it definitively.

Does anyone have any experiences with using this product or with the break-in times?

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These devices clean up noise/interference on the power supply.
I’ve tried a few different brands, but not the this Furutech.
I still have & use an IsoTek IsoPlug, .
When used on my power supply it makes very little difference, I suspect because the power supply is ‘clean’.
Whereas using it on a friends supply & its more effective, I suspect because his supply in not as clean & his house has old 1940/50’s wiring.

Do you know how they are doing this?

I bought one and got the exact same results as you did. I kept mine in because I like the sound improvements it brings. I didn’t find it changed much during burn in.

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The basic is a passive circuit of X capacitor(s) across L&N with a net of Y caps, resistors & VDR(s) Some include Y to E if E is in the design
There are now more ‘advanced’ designs from people like iFi who use electronics for active noise cancelation.

I don’t know what the Furutech is, judging by the price at I suspect is an active device, but it is Furutech, so who knows

This is a typical circuit for the passive type

Cool, thanks much

So this Furutek product could consider a filter?

Could this damage the dynamics of Naim products?

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It has not damaged the dynamics in my Naim system.

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Strictly speaking its not a filter as power does not pass through it, its sits across L&N (in shunt). Maybe if you want to categorise it, a noise suppressor would be better.
In my experience with other brands of the same type of device, it does not affect dynamics.

It seems to me that the Furutech product, at least in these first hours of listening, goes to “thin” the sound with a general softening.

I will give my final remarks in all sincerity at least in 24 hours.

I also have Nordost QV2 and QK1 in my system. They improved the sound without dulling dynamics.

Would this remove the noise from switching a light on & off?

No, you need to install a switch arc suppression cap on the switch.
Replacing the switch with a modern one (that has a fast action) might also fix it

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I let the device run in for more than 24 hours, always plugged in.

I have to confirm the impressions I had at the beginning.

The product makes the treble clearer and more crystalline but the sound loses its naturalness.

Above all the voices seem to pass from the softness and feeling of “real” to an unnatural voice.

For example, by listening the Eagles song The last resort, Don Henley’s voice goes from natural and credible to a more subtle, unnatural and almost artificial voice.

There is an overall feeling of less dry sound by inserting the Furetech NCF Clear Line device.

It almost seems that an equalizer was inserted that emphasizes the treble, this is exactly the feeling I have.

I’m sure not everyone will like the effect of this product and for example I don’t like it.

It’s almost like a more crystalline sound effect emphasized on the treble which might mistakenly suggest sound improvement but the sound in general loses its naturalness in my opinion, too thin and tiring after a while too.

I don’t understand how many have said that it “improves” the sound and I wonder where.

I prefer my Naim system without this product because I feel more dry and natural sound.

Now I would like to understand what exactly the Furutech NCF Clear Line does.

Does it filter?

Does it equalize?

Does it change the sound?

How does it affect the current?

I’m just curious what exactly it does to the current because that remains a mystery to me.

Something will definitely do because you absolutely feel the effect whether the product is plugged into the mains or not!

Perhaps it might have some effect on some less revealing or inexpensive system but regarding the effects that are advertised: more 3D sound, enlarged soundstage, etc. I didn’t feel any improvement other than a worsening with the soundstage slightly lowered.

I am sorry to say this but I have to say it because I was hoping to improve my system.

I therefore decided to return the product and in my experience I must advise against it to anyone.

I use the iFi AC iPurifiers in my system - one can get five of them for the cost of two of the Furutechs. The two in my server closet on a Supra power strip in my ‘noisy’ office made the most difference - the one plugged into the V1/160 mains made only a subtle difference but didn’t change the sound for the worse, but a bit better, clearer. Plus the iFi’s offer surge protection, not sure about the Furutechs.

Does it filter?
No I answered that yesterday, no current passes through it so it’s not a filter
What it does is clean up line noise/hash & maybe some sine wave distortion

Does it equalize?
No, how can it? its only connected to the input power

Does it change the sound?
I seems to have done so with your system, with similar devices on my system it makes very little difference

How does it affect the current?
It does not affect the current draw to your equipment.
It may possibly pull a few milliamps itself, if its a little warm then that is an indicator that is so.

iFi AC iPurifier is a different product it’s an active filter and Naim systems don’t like any filter other than something high quality like a very powerful current regenerator or high end products like Puritan 156

I would simply like to understand the working principle of Furutech NCF Clear Line because it is not clear at all.

What exactly does it do?

Anyone know?

I did not say that it absorbs current in fact the device remains cold all the time.

Because the effect is to equalize the high frequencies or to emphasize them.

Mid frequencies are also made thinner and more unnatural.

@aristoweb same positive experience. See this thread: Furutech NCF Clear Line-E - #17 by IvdZ

I have the same Naim system as you.

Yes, I had read that thread and that thread had prompted me to purchase.

I confirm that the sound becomes thinner and less natural.

There is simply an emphasis on the high frequencies and no difference on the sound stage which is actually a little lower in height.

By removing the Furutech NCF Clear Line the sound returns natural and with the characteristic Naim timbre.