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So has anyone measured how the IFI Audio AC Purifier is supposed to work?
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ninetylol
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The meter he is using is usually used to sell useless AC filters (converts inaudible high frequency content to audible). Funny how it is being used now to show this thing actually makes things worse!
ninetylol
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Theres another Video where He is measuring on his Laptop, I dont think this is fake and this guy isnt really a big influencer from what I see, so no reason to make wrong claims.
Read my post again. You completely misunderstood what I wrote.
ninetylol
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Oh i though you implied the meter is snake oil nvm
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As I'm going through old threads I find new evidence. @amirm has already done measurements of the purifier:
https://www.audiosciencereview.com/...ts-of-schiit-yggdrasil-v2-dac.3607/post-87027
https://www.audiosciencereview.com/...ts-of-schiit-yggdrasil-v2-dac.3607/post-87027
Veri
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solderdude
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A DC purifier is easy to design and can actually do something as one can also filter all audio frequencies.
I reckon it is similar to the 'ripple eater'.
It won't do anything about common mode crap leaking through SMPS which may be a bigger issue than a small ripple.
In most cases I would expect DC fed devices to do some voltage rails cleaning/smoothing/regulation anyway.
I reckon it is similar to the 'ripple eater'.
It won't do anything about common mode crap leaking through SMPS which may be a bigger issue than a small ripple.
In most cases I would expect DC fed devices to do some voltage rails cleaning/smoothing/regulation anyway.
Veri
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I see, makes sense. Probably not worth much then
as long as it doesn't inject noise like this AC purifier that's something though, lol
I see these things from the opposite direction.
Mains powered equipment is designed to be -you got it- mains powered. Mains power is not a perfect sine wave. The designers know this, so it follows that any bit of mains powered equipment which performs badly in the presence of normal mains shortcomings is badly designed.
Any piece of hifi that needs a mains purifier to work properly is an incompetent design and best replaced by something properly engineered.
Voila! requirement for mains purifier = 0
Mains powered equipment is designed to be -you got it- mains powered. Mains power is not a perfect sine wave. The designers know this, so it follows that any bit of mains powered equipment which performs badly in the presence of normal mains shortcomings is badly designed.
Any piece of hifi that needs a mains purifier to work properly is an incompetent design and best replaced by something properly engineered.
Voila! requirement for mains purifier = 0
differenceclouds
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I just ran into this thread and was looking over those plots. Funny thing, I just bought a Belkin 10 outlet with metal casing surge protector and was reading the box. On the back it says it has a EMI/RFI noise filtration from 150kHz-1MHz and up to -40db reduction.As can be seen it does nothing in the audible range (below 10kHz) acc. to their own plot:
No attenuation below 10kHz.
The active noise cancellation is a very old trick that was already used by JLH called the ripple eater.
This was for DC and did work in the audible band.
You can't do this for AC as that already consists of AC with lots of harmonics.
Funnily enough in their manual it shows a picture that shows 40dB noise reduction even at 1Hz.
This is a pretty nifty feat to suppress the 50/60Hz mains with 40dB.
One would normally call that a 100:1 transformer.
Now, I only bought this for use as an extension for my computer, printer, RMC, and Headphone amp. I didn't buy for audio use and didn't even know about the EMI/RFI filtration. Is there something more going on with filtration in these ranges?
Maybe one of the Engineers can chime in and explain why?
Last edited:
solderdude
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It will be fine for that. Aside from the surge protector there is a simple basic common mode filter inside.
Perfectly fine to use it for the intended goal.
The listed attenuatio and frequency range where the maximum attenuation will be reached in sounds realistic.
Well designed equipment and computer/printer etc. will also have at least basic but probably even more filtering inside anyway in order to pass EMC testing/regulations.
In general no one will ever notice the difference between filtered and non-filtered mains unless one has some serious (ground loop) issues going on.
And even there mains filtering might very well not be effective anyway.
Thank You for the reply and info, I really appreciate it learning something new every day.
@solderdude
Hey so I've been playing around with the EMI stuff for a while now, I've been trying to get it as close to 0 as possible, but haven't been able to.
So far, here is what I tried:
I've bought one of those tacima mains conditioners, like these ones:
And I've also bought the plug in mains conditioners, similiar to the ifi ones on this thread.
My experience with them has been ok, they do actually lower the EMI using my EMI measuring tool (similar to the japanese guy was using).
I've also tried getting the ifi mains conditioner one too, the really expensive one:
But it didn't actually do anything, it didn't lower the mVA at all, was very disappointing.
I've also gotten one of those online UPS devices:
The UPS one did a decent job, it lowered it from 300+mVA down to 100mVA, however it's still at 100mVA, I'm guessing the lead acid battery is maybe creating some interference or something?
I also tried an inverter:
uk.renogy.com
Interestingly, that gave a similar output to the UPS, around 100mVA.
My question is, is there any device I can get that could lower it down to below 10mVA? Would a UPS with a lithium ion battery work much better?
Hey so I've been playing around with the EMI stuff for a while now, I've been trying to get it as close to 0 as possible, but haven't been able to.
So far, here is what I tried:
I've bought one of those tacima mains conditioners, like these ones:
And I've also bought the plug in mains conditioners, similiar to the ifi ones on this thread.
My experience with them has been ok, they do actually lower the EMI using my EMI measuring tool (similar to the japanese guy was using).
I've also tried getting the ifi mains conditioner one too, the really expensive one:
But it didn't actually do anything, it didn't lower the mVA at all, was very disappointing.
I've also gotten one of those online UPS devices:
The UPS one did a decent job, it lowered it from 300+mVA down to 100mVA, however it's still at 100mVA, I'm guessing the lead acid battery is maybe creating some interference or something?
I also tried an inverter:
12V to 230V 1000W Pure Sine Wave Inverter (with UPS Function) | Renogy UK
Whether for a van or a cabin, the Renogy 1000W Pure Sine Wave Power Inverter acts as a DC to AC converter that allows you to power your household appliances.
uk.renogy.com
Interestingly, that gave a similar output to the UPS, around 100mVA.
My question is, is there any device I can get that could lower it down to below 10mVA? Would a UPS with a lithium ion battery work much better?
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