[gregorio]

"If you think of mains power as the ‘gasoline’ fuelling your audio system, the AC iPurifier is the product that ensures that it’s getting a clean, super premium blend to deliver the best possible audio fidelity."

OK, let's think of it as gasoline. 1. If you add some sort purifier to your premium blend, it does NOT suddenly become a super premium blend, that's defined by the refinery, not by some purifier/filter. 2. In the case of dirty gasoline, adding a purifier/filter will make the fuel cleaner and your engine run better, which is why every competent car manufacturer ALREADY includes a fuel filter and therefore adding another one achieves NOTHING! So it is with say a DAC, any competent DAC has to take mains power, convert and in the process purify/clean it. Adding another "purifier" before the built-in purifier does absolutely nothing unless you have an incompetently designed DAC which doesn't have a competent purifier. However, rather than spend $300 trying to compensate for this single aspect of an incompetently designed DAC, I'd rather spend it on curing all the incompetently designed aspects in one go, by buying a competently designed DAC in the first place ... but that's just me!

G

 

[mulder01]

For the people asking about the surge diverter protecting the equipment when the equipment isn't actually plugged into it, that's how all surge diverters work (the ones that I am aware of anyway). I am a sparky and and if someone wants one put in their switchboard, it simply has the main power supply connected on one side and the earth on the other. Under normal voltage it is open circuit, if the voltage increases, it creates a short to earth. The idea being that the additional power flows along the path of least resistance (the surge diverter) rather than through your appliances. They are always connected in parallel with stuff rather than series.

 

[Swetone Audio]

The manufacturer claims that this device is an active noise cancelling system. The device shown has no input or output terminals, it just plugs into the AC power. Every active noise cancelling system out there has an input and an output terminal. They are separate. This has neither.

Active noise cancelling typically uses a feed forward technique, wherein the signal is filtered to reveal noise only, then the noise signal is inverted and fed back to the signal downstream. Thus, an input and an output terminal are required.

The only type of noise suppressing device that I'm aware of that does not require input and output terminals is an ordinary capacitor (or something similar to that) connected across the AC power line. That is a passive device however.

 

[Matias]

I am just waiting for them to show up online to buy a pair.

 

[iFi audio]

AC iPurifier
Part 1/5: Actively goes where no purifier has gone before



Mains is the fuel that powers an audio system. Whether it is clean or not has a material impact upon quality and the user’s enjoyment of playback. iFi’s latest ‘power product’, the AC iPurifier, is no ordinary mains purification commodity.

Technologically advanced, it is an ACTIVE not a passive product, so it goes above and beyond and cancels far more noise across the frequency range than passive devices.

It is effective against both:

1. Common mode noise existing equally on both of the power pins, referenced to the earth pin.
2. Differential noise existing only between the two power pins – the net to earth is zero.

They are, in effect, flip sides of the same coin and are the bane of audio systems regardless of the type of power supply.


Nullifies noise others can’t reach

Compared to other generic noise filters, the AC iPurifier is superior because it is ACTIVE as opposed to passive. This enables it to achieve a far more comprehensive termination of noise across the frequency spectrum. As noise exists across the frequency range, this clearly means the AC iPurifier is unparalleled when it comes to neutralizing noise.

This chart compares the AC iPurifier (green line) which is ACTIVE to generic mains filters (red line) which are typically passive.



The effective noise reduction difference is as different as night and day.

1. MUCH better at up to -40dB and…
2. Effective across a wide frequency range, compared to passive filters which cover only very high RF frequencies.

Every audio system benefits from the AC iPurifier

The AC iPurifier is designed for use in ANY mains powered audio system and is very effective when added to modern audio systems that have an abundance of digital and analogue components. Typically these systems are powered from a plethora of mains plugs. All of these ‘wall warts’ can add their own unwanted noise issues and pollute the local mains supply. However, the design of the AC iPurifier is such that it is even more effective if several are used to ‘contain’ the same type of noisy sources.

Insert it into the AC mains wall outlet supplying the audio system OR insert into the mains extension block powering the audio system. Try both locations to determine which has the greatest impact on improving any noise issues.



Bristling with serious Power Technology

Compared to similar AC power products, the AC iPurifier can boast the technological features below, making it far more comprehensive and effective than its rivals.



Stay tuned, there's more!

 

[Rob N]

Are these available in the UK?

 

[Matias]

@iFi audio it seems that Nordost Qv2 does the same type of active counter noise injection as the AC iPurifier. I know about the other features, but as far as noise removal, are there any differences?

Still waiting for dealers to list it online to order mine.

Thanks.

 

[Chefano]

I really would love to see the results from a double blind test of this product, varying from an el cheapo system to a high end.

 

[mulder01]

I really would love to see the results from a double blind test of this product, varying from an el cheapo system to a high end.

Yeah like we always get with every product

I'm sure it does something - it probably does what they say it does - if you have noise on your AC line, it is possible to suppress it, and it is possible to divert over voltage surges. Does that make music sound better though? Well, hmm...

The other question is: is your incoming power bad? I have a friend who used to live in an apartment building with construction going on around him and he got audible popping through his headphones when someone arced up a welder or turned on a drop saw. If it can stop things like that then great, but if your power is already good, well, you can't clean it if it aint dirty... There are a lot of variables in the power supply side of things that would effect results.

TBH for $99 I don't care too much if people want to buy one for peace of mind. Kinda no different to buying Schiit Wyrd for the USB signal. A good power board with surge protection on it costs that much.

OTOH if a company is going to charge 4-5 figures for a power conditioner and suggest you put it on an absurdly priced isolation base to get the most out of it, then I would insist on seeing some sort of proof on that one.

 

[Chefano]

Yeah like we always get with every product

I'm sure it does something - it probably does what they say it does - if you have noise on your AC line, it is possible to suppress it, and it is possible to divert over voltage surges. Does that make music sound better though? Well, hmm...

The other question is: is your incoming power bad? I have a friend who used to live in an apartment building with construction going on around him and he got audible popping through his headphones when someone arced up a welder or turned on a drop saw. If it can stop things like that then great, but if your power is already good, well, you can't clean it if it aint dirty... There are a lot of variables in the power supply side of things that would effect results.

TBH for $99 I don't care too much if people want to buy one for peace of mind. Kinda no different to buying Schiit Wyrd for the USB signal. A good power board with surge protection on it costs that much.

OTOH if a company is going to charge 4-5 figures for a power conditioner and suggest you put it on an absurdly priced isolation base to get the most out of it, then I would insist on seeing some sort of proof on that one.

This product is claiming benefits on snake oil territory, well, for a company that big would not hurt do that kind of testing against an old good CLC filter.
Nah, lets jump into the bandwagon, afterall people buy magic stones to put them over their gear and do believe they are working and do listen to the differences btw.

 

[iFi audio]

I really would love to see the results from a double blind test of this product, varying from an el cheapo system to a high end.

We look forward to impressions of users here too. On a side note, AC iPurifier should be also seen as a diganostic tool, something which will indicate whether polarity and earth are OK.

Are these available in the UK?

Yes, they are. Please feel free to ask your local iFi representative.

@iFi audio it seems that Nordost Qv2 does the same type of active counter noise injection as the AC iPurifier. I know about the other features, but as far as noise removal, are there any differences?

Still waiting for dealers to list it online to order mine.

Thanks.

It is our policy to be silent about what other manufacturers do, hence with this one you'll have to wait for regular folks to chime in.

 

[mulder01]

This product is claiming benefits on snake oil territory, well, for a company that big would not hurt do that kind of testing against an old good CLC filter.
Nah, lets jump into the bandwagon, afterall people buy magic stones to put them over their gear and do believe they are working and do listen to the differences btw.

Not saying I'll buy one, but if they sell it as a filter for your power supply and it filters your power supply, then it is what it says. What's the specific bit you're claiming as false?

 

[gregorio]

Not saying I'll buy one, but if they sell it as a filter for your power supply and it filters your power supply, then it is what it says. What's the specific bit you're claiming as false?

Assuming it actually does provide what it claims to provide then the specific bit I would claim is false is "Every audio system benefits from the AC iPurifier". Any competently designed DAC will already effectively filter the noise from the power supply, reduce/isolate it from the output to well below audible levels. So, not every audio system will benefit from the iPurifier, in fact, probably very few would. BTW, your friend's situation is probably caused by the arc welder or drop saw sucking up a lot of current from an electrical installation not designed for such sudden, large current draws, resulting in short duration brown outs. From what I've read, the iPurifier does not compensate for brown outs (under current or voltage), it only appears to filter noise from the power supply and provide protection against over current/voltage (power surges), in which case it would not have solved your friend's issue. He would need a UPS.

G

 

[mulder01]

Depends. Back EMF from inrush currents can cause problems too... Could be a bunch of things

Won't improve the sound of my DAP though - I'm pretty sure of that But yes, you would hope that well designed power supplies should be able to work with dirty power.

I think it's in the wording of the phrase too - if you can check the polarity, that's a benefit. If you can divert a surge, that's a benefit...

Mmmm... Just trying to think why I started posting in this thread... I'll leave y'all alone I think...

 

[iFi audio]

AC iPurifier
Part 2/5: Mains noise. A real bane.

Power supply noise is the bane of every audio system. There are always multiple sources of noise and they come from two main sources – inside and outside.

External noise is all around

This chart shows that noise is anywhere and everywhere and some of it inevitably ends up in the mains that supplies the audio system, due to the mains wiring acting as aerial. Most of the sources, we can do little about as they are found in everyday life such as radios or mobile phones.



The next chart shows the ‘local’ noise sources found in and around an audio system.


Local noise comes from hi-fi components

These sources of noise are found in hi-fi systems and come from three main sources:

1. AC mains power supplies
2. Switch-Mode Power Supplies
3. Digital circuitry.

From left to right:

• The first set of noise sources (10k > 10MHz) relate to AC supply rectifiers and their harmonics caused by Linear Power Supplies (LPS). Yes, they make a noise!
• The second set of noise sources (67k > 200 MHz) is caused by Switch-Mode Power Supplies (SMPS). By comparison, these harmonics run in the higher frequencies.
• The third set of noise sources (8 MHz > 500 MHz) is caused by digital circuitry, clocks and their harmonics. And this type of noise exists in the most upper frequencies.
• You can see from the chart that the concentration of noise is from 30kHz upwards (the lower the dB, the less influential is the noise).

LPS vs SMPS

It is worth noting that, as much as LPS designs get a good reputation and SMPS designs get a bad reputation, the reality is somewhere in between. And the situation is dynamic.



First, LPS designs are on the whole, good and, on average, are quieter than poorly designed SMPS power supplies (which tend to be more for charging mobile phones and are not optimised for noise). This is why LPS is often perceived as superior to SMPS.

Hybrid and electric cars used to be shunned, yet they are now all the rage. We believe the same is happening for SMPS. These are now more environmentally-friendly and consume far less power. Whereas all SMPS used to be ‘noisy’, we are one of the few companies who have broken down the SMPS into its constituent parts and fundamentally re-designed it for audiophile use ie super low-noise. The iPOWER is the ‘Model 3’ of SMPS power supplies.

Nevertheless not everyone has an iPOWER at their disposal. It is therefore important to be able to effectively deal with normal SMPS noise which can be quite severe.

The next section explains which aspects of the AC iPurifier target the different groups of noise and how this compares to the common approach.

Stay tuned, there's more!