ifi DC iPurifier Power Filter Review

[solderdude]

Thanks for the help, I'll try this.

What kind of noise are you hearing ? Hiss, sharpish hum ? weird noises ?

 

[Jimster480]

I would be interested in seeing all these "enhancement" devices tested with crap DACs. Testing them with excellent DACs doesn't seem fair, little room for improvement. FWIW

I have no desire to improve my D50s but I once owned a 1st generation Modi and it needed some help.

I don't know if its even worth the money. If you have a crap product and you have to buy some crap to fix your crap product. Then its still crap.

 

[CharlesC]

I don't know if its even worth the money. If you have a crap product and you have to buy some crap to fix your crap product. Then its still crap.

True but the conclusion that it isn't worth the money is different than the conclusion that it doesn't do anything.

 

[solderdude]

It does do something. The measurements clearly show the DC has lower noise on it.
That doesn't mean it will lead to audible improvements... it might, in some rare cases where the circuit it feeds has poor PSRR and the used power supply is noisy.
It clearly doesn't improve anything on the D50 nor is it to be expected. I expect the D50 to have proper input voltage filtering.

You cannot ask Amir to test it with lots of equipment to see which improves or not.
Maybe he owns some device that has been shown to have poor PSRR and can use it on such devices.
It is rather pointless to test something that is almost guaranteed to not react but fact is that a lot of people scream it always improves audio equipment (always tighter bass, more 'air' and 'space' etc.)

 

[bobbooo]

What kind of noise are you hearing ? Hiss, sharpish hum ? weird noises ?

It's a high-pitched buzzing, which sometimes changes into a squeal. I've confirmed it's still there without any source connected, even with the energizer volume all the way down, and is there no matter which mains socket or surge protected extension lead I use. On further listening it seems like it's only in the right channel, so I think it's a fault with the headphones/energizer. I'll send it back I think and see if the replacement is any better.

 

[solderdude]

Yes, could be the bias generator or leakage in a driver.
In any case, as it is in one channel only it is unlikely to come from the power supply.

 

[chook]

It does do something. The measurements clearly show the DC has lower noise on it.
That doesn't mean it will lead to audible improvements... it might, in some rare cases where the circuit it feeds has poor PSRR and the used power supply is noisy.
It clearly doesn't improve anything on the D50 nor is it to be expected. I expect the D50 to have proper input voltage filtering.

You cannot ask Amir to test it with lots of equipment to see which improves or not.
Maybe he owns some device that has been shown to have poor PSRR and can use it on such devices.
It is rather pointless to test something that is almost guaranteed to not react but fact is that a lot of people scream it always improves audio equipment (always tighter bass, more 'air' and 'space' etc.)

+1, It seems kind of pointless to test this type of devices with a DAC which is properly designed and is already a good performer. Having a noisy DAC for this test would make more sense, not that one could justify spending $99 for this thingy instead of getting a better DAC

 

[BobPM]

+1, It seems kind of pointless to test this type of devices with a DAC which is properly designed and is already a good performer. Having a noisy DAC for this test would make more sense, not that one could justify spending $99 for this thingy instead of getting a better DAC

I kind of agree. I use the ipurifier SPDIF purifier on the toslink output from my roku into a Marantz SR-7008 SPDIF. Does it help? I think if does but have no way to tell. Unfortunately, this Marantz model came out before was before the new HDMI 4K standard and won't pass through 4k content. I have to use the SPDIF into the receiver to get surround and send the HDMI straight to the TV. When Darko reviewed the device he was clear that it did nothing to improve an already quality implementation.

 

[pedrob]

This is a review and detailed measurements of the ifi DC iPurifier DC (power) filter. It is on kind loan from a member. The iPurifier costs US $99. Looks like there is an updated, iPurifier2 now.

Of course, if you bought this device and plugged it, you immediately hear better bass, more air, more microdynamics and resolution. All of that happens not because the device made these changes, but because when you focus on what a device does, you listen differently. When the sound waves coming out of an audio device has not changed, the only thing that must have, is your perception.

Is that comment based on fact or a misguided assumption that everyone is a slave to their emotions and therefore incapable of making decent assessments?

It looks like it does what it claims by reducing the DC noise floor. Whether it is needed is another issue and that surely depends on many factors including the sensitivity of the device it is powering.

 

[Nango]

Of course, a human being is always conditioned by its emotions, past sensations, experiences, socialisation, etc. It is no machine.

 

[Killingbeans]

Is that comment based on fact or a misguided assumption that everyone is a slave to their emotions and therefore incapable of making decent assessments?

Ask that question to anybody who has an occupation with a strong influence of human factors, and you'll quickly find that this assumption is far from misguided

It looks like it does what it claims by reducing the DC noise floor. Whether it is needed is another issue and that surely depends on many factors including the sensitivity of the device it is powering.

If a product needs an inline DC filter to avoid an audible amount of noise it's either way too cheaply made (as in; a piece of junk), or it's been designed by an incompetent engineer who should have included the filter on the PCB in the first place (again... a piece of junk).

Buying products to fix another badly designed product is just coo-coo, if you ask me.

(Not that I'm a saint. I've done plenty of coo-coo thing in my life.)

 

[pedrob]

Ah if everything were so simple.

The truth is nearly all products are built to a price and by necessity include compromises. Even mid market products can be improved with a little thought, knowledge and imagination.

 

[wasnotwasnotwas]

Ah if everything were so simple.

The truth is nearly all products are built to a price and by necessity include compromises. Even mid market products can be improved with a little thought, knowledge and imagination.

But not with an iFi power filter thingy.

 

[Killingbeans]

The truth is nearly all products are built to a price and by necessity include compromises.

I know, but pushing PSU induced noise to a point below audibility is not something that requires a particularly great effort. Most high-end manufacturers wants people to think of it as some elaborate art form when it's actually trivial business for any respectable EE.

Besides, is a product that has even the most basic good practices cut in the name of profit worth spending any time on at all?

Even mid market products can be improved with a little thought, knowledge and imagination.

To an audible degree?

 

[pedrob]

But not with an iFi power filter thingy.

Couldn't agree more. When it comes to power supplies size matters so there's room to fit some serious capacitors.

Unless they've thrown the book out and discovered a way to miniaturize everything. LOL

 

[pedrob]

This is a review and detailed measurements of the ifi DC iPurifier DC (power) filter. It is on kind loan from a member. The iPurifier costs US $99. Looks like there is an updated, iPurifier2 now.

Power Quality Measurements
Let's get rid of the DAC altogether and just hook up the USB power to the audio analyzer. Yes, I can do that but you should not do it with your audio gear or you will blow up your speakers good. Here is the comparison now:
View attachment 45110

Now we see that the iPurifier is indeed cleaning up the USB power. It is lowering its noise and getting rid of fair amount of very high frequency spikes. Why did we not see this effect when testing with the DAC? Again, that is because the DAC was also performing this filtering so it did not benefit from it being beforehand. No decent DAC assumes USB power is clean.

/

It seems the device does in fact do what it claims!

Better to leave it up to the consumer to decide if it might be useful. It's a fact that higher end equipment can be sensitive to interference and a perfectly clean supply is an impossibility, so anything that lowers the floor can be helpful in certain circumstances.

 

[Frank Dernie]

It seems the device does in fact do what it claims!

Better to leave it up to the consumer to decide if it might be useful. It's a fact that higher end equipment can be sensitive to interference and a perfectly clean supply is an impossibility, so anything that lowers the floor can be helpful in certain circumstances.

If something purportedly designed to be powered by the mains and connected to a digital source is sensitive to interference from either of those connections it was designed by an incompetent fool and is not high end by any measure other than, perhaps, an encouragingly high price appealing to the gullibility of some purchasers.

Indeed one should leave it to the purchaser to decide, but this site is here to check how well items do what they claim and give clear indication for the benefit of the technically uneducated some of whom can be won over by a skilled confidence trickster.

 

[Thomas savage]

Better to leave it up to the consumer to decide if it might be useful

Err , how is ASR contradicting this ?

People still have free will , dont they? I know personal responsibility is fast becoming a thing of the past but still.

 

[Jimbob54]

It seems the device does in fact do what it claims!

Better to leave it up to the consumer to decide if it might be useful. It's a fact that higher end equipment can be sensitive to interference and a perfectly clean supply is an impossibility, so anything that lowers the floor can be helpful in certain circumstances.

Sounds to me more an excuse for some "higher end" equipment not being designed properly to filter DC. Imagine spending $000 on something and needing to spend another $100 to get it to perform at the level that a $100 DAC can already do.

 

[Veri]

It seems the device does in fact do what it claims!

Better to leave it up to the consumer to decide if it might be useful.

Well yeah, makers of these kind of tweaks are betting on consumers deciding/thinking they need it lol, that's their whole market.