iFiAC iPurifier - Mains Audio & Video Noise Eliminator/Line Conditioner/Filter/Isolator/Purifier/Whole Entertainment System Protection

It was a couple of months ago that I first became aware of the iFi AC iPurifier through the end user reports on several of the computer audio related websites that I frequent. When considering how to best implement and test these devices within my all digital computer based A/V system I decided that it would be convenient to place one AC iPurifier in each of the isolated ground hospital grade duplex outlets that my 4 pieces of digital equipment draw their power from.In order to get an idea of the contribution made by each individual AC iPurifier I staggered their deployment of one in each of the 4 duplex outlets that my PS Audio Extension Link AC distribution hub has which provides AC power to the entire A/V system allowing the use of one AC iPurifier in each duplex outlet for each piece of equipment. The following description describes the order in which I installed the AC iPurifiers along with a brief evaluation of the change that each AC iPurifier brought to the overall audio and video performance within my A/V system:1) I installed the first of the 4 AC iPurifiers in the outlet which the video monitor with it’s Switch Mode Power Supply (SMPS) uses to draw it’s AC power. I immediately noticed a substantial improvement in picture quality along with an accompanying improvement in audio playback quality as well.2) Next I installed an AC iPurifier directly into the same duplex outlet that my Mac Mini computer which supplies audio over USB and video over HDMI is plugged into. I have read many times that computers designed for general use like the Mac Mini use very noisy Switch Mode Power Supplies and because of this the best advice is that they should never be used in conjunction with sensitive purpose built A/V equipment. The introduction of the AC Purifier soon offered a very clear and undeniable confirmation of this advice.As with most of you reading this review I have spent many years experimenting with ways to improve both my audio and video playback quality keeping in mind that everything we see and hear from our A/V systems was once AC power coming from the wall. That said, the AC iPurifier which was used directly as a ‘firewall’ in parallel with the Mac Mini at the shared outlet it uses to draw AC power brought a level of improvement that in my estimation is in inverse proportion to what must be the huge amount of RFI and leakage current pollution that this general use computer otherwise distributes back into the collective supply of AC power which is shared by all of the other A/V equipment. I am very reluctant in making extraordinary claims, but I in this case I must admit that the improvement here was definitely on an order of magnitude allowing both the audio and video equipment to shine and for the first time finally be able to operate ever so much closer to their original intended design capability once the AC power that the entire A/V system uses was cleaned up by the AC iPurifier.3) The third AC iPurifier deployment was to the outlet that the Wadia 151 Power DAC with it’s SMPS uses. This device processes PCM in S/PDIF format into PWM which is subsequently L/C filtered to produce a speaker level signal. The perceived improvement here was very much on the same level as was noticed with the treatment of the video monitor where there again was an appreciable improvement in overall sound quality accompanied by a noticeable improvement in picture quality as well as the general supply of AC power was once again filtered from the RFI and leakage current that the Power DAC with it’s SMPS was creating which in turn benefits all of the equipment using the now less polluted supply of AC power.4) The SOtM DDC which converts galvanically isolated PCM over USB to S/PDIF format over Fused Silica Glass Toslink for processing by the Power DAC is the only piece of equipment in the system that uses a Linear Power Supply (LPS). I mention this because the deployment of the AC iPurifier to the duplex outlet which this LPS draws AC power from was the only instance in this evaluation where there seemed to be no discernible change in the performance of this device or any other equipment in the A/V system. My opinion about this is that this LPS is probably not creating the same large amounts of RFI and leakage current pollution as the Switch Mode Power Supplies of the other 3 pieces of equipment are and subsequently there is simply little or no noticeable improvement for the AC iPurifier to make in this deployment.Conclusion: Three of the 4 iFi AC iPurifiers which I installed over a week’s time have collectively proven to provide the greatest and most transformational improvement thus far to both the audio and video quality of my all digital A/V system which I have been working diligently to improve for many years. I know these truly spectacular improvements as the single most impressive set of enhancements I have ever seen or heard in the performance of my A/V system and the thanks go to the AC iPurifier’s adept elimination of the copious amounts of RFI and leakage current pollutions that were once being spewed back into the supply of AC power severely compromising the performance of the equipment. The AC iPurifiers have now enabled that same equipment to function strikingly closer to how it was originally designed to perform and in this case resulting in a true ‘component level’ upgrade.

My turntable was picking up some AC line noise caused by a powerline network adapter running on the same circuit. Plugging this device into the first receptacle of my power distributor (ZeroSurge 8R15W-I, which by the way does nothing to attenuate line noise in my tests) greatly reduced the audible noise (I'd guess at least 10db). I purchased this device based on a YouTube upload titled "iFi AC iPurifier review — PROOF that it works!" and I can confirm my result is similar to that shown in the video. A single AC iPurifier is not canceling ALL the powerline AC noise, but I'm impressed because truthfully I was expecting it to do nothing.I should say that my house has very clean mains power. When I moved in I upgraded to a 200amp service panel, which required the power company to install a brand new transformer to accommodate the service drop. When the powerline network is off, my phono stage is dead quiet until I turn my amp past normal listening level (around -15db), where inevitable hum creeps in. If, like me, you have clean mains power, I'm not sure the iPurifier is going to make an audible difference, especially if you're not using a phono preamp, which must multiply the signal and any accompanying noise by a factor in the tens if not hundreds (for moving coil).If you're not happy with your system, the iPurifier will almost certainly not help. However, I would say the iPurifier is 100% worth it if either a) you have audible AC line noise, b) you're happy with your current system and want to get the most out of it.

At first listen it can/might seem like the iFi active noise cancellation tech is really good. Unfortunately after extensive listening my conclusion is that there is something seriously wrong with the technological implementation of the idea behind the tech. I was initially quite excited by the results, so I bought more of their items, an iPower filter II, 2 iFi ACpower filters, an iFi USB filter and an iFi Ethernet filter. I spent 2 months trying to get the audio systems I used the products in to sound right, but I was plagued by a number of issues. High frequencies during louder and more complex passages seem to have a crackling sound added at their peak. There are random bits of lower frequency noise showing up all over the place. The sound systems lost all of their musical engagement, they no longer connected my soul to the soul of the music. My entire being was unable to relax, there is a certain tightness in my chest when I listen with the iFi products installed. All of those issues went progressively away as I removed iFi units, one by one, until they were all removed and the sound system regained, for the first time in 2 months, it's musicality and soulful engagement. My body relaxed. This is not a joke, not BS. It is something I have explored and consider a very real fatal flaw of the iFi tech as delivered. It seems like the products introduce some sort of phase issue that twists and contorts the sound in ways that are unnatural and deeply unsettling to the Human Body. It is unfortunate that it took me 2 weeks longer than my return period to figure this out, so I am stuck with $300 of iFi products I will never use again and iFi has declined to accommodate any sort of return/refund to me. Don't get yourself into a similar bind, stay away from anything they make that contains their active noise cancellation technology.