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ifi DC iPurifier Power Filter Review

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#21
The problem with that thought, is this thing costs $100...they've already precluded all the "crap dacs" from being in the chain here, unless you believe there are ton of consumers spending hundreds of dollars on "fixes" to their $25 audio equipment...
You should see what my son spends on his old Jeep Wrangler.
 
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#22
Might as well replace a crap dac with an "excellent dac" then, before having to resort to tweaks and other money wasters :)
I agree with all these arguments but before concluding it doesn't do anything maybe it should be tested against a product that actually needs some help. The Bifrost got a bad review here and it costs a lot more than $100 (I don't know if it has a DC input but not all crap DACs are cheap).
 

majingotan

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#24
I agree with all these arguments but before concluding it doesn't do anything maybe it should be tested against a product that actually needs some help. The Bifrost got a bad review here and it costs a lot more than $100 (I don't know if it has a DC input but not all crap DACs are cheap).
Bifrost doesn't have external AC to DC power supply like other DACs so this thing is not even applicable to it. Try iFi iUSB 3.0 that I use instead which fixes the badly implemented muting/sample rate relay system from the Bifrost 2.
 
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#25
This is true but IMHO if a DAC is badly engineered using bolt ons to remedy the poor design is like putting lipstick on a pig.
Better to get rid of it and just buy a piece of properly engineered non-crap surely?
The conclusion that a remedy is not cost effective is different than the conclusion that the remedy doesn’t do anything.
 

solderdude

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#26
I agree with all these arguments but before concluding it doesn't do anything maybe it should be tested against a product that actually needs some help. The Bifrost got a bad review here and it costs a lot more than $100 (I don't know if it has a DC input but not all crap DACs are cheap).
I don't think the poor performance of the bifrost is due to its power supply so the i-purifier DC cannot help here either.
Only devices with a poor PSRR and crappy DC supply may possibly benefit.
As is does not do anything about groundloops either chances are, in a technical sense, it has a very limited usability.

It will probably work great in making people believe the sound will be better when it is used so in those cases undoubtably an improvement will certainly be heard.
 

phoenixdogfan

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#27
Might as well replace a crap dac with an "excellent dac" then, before having to resort to tweaks and other money wasters :)
Given all the really excellent DACS retailing for $125 or less Amir has already reviewed, why would anyone spend that same amount to improve the performance of their POS Dac.
 

bobbooo

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#30
Any noise is most likely not coming from the external power supply but rather from the internal electronics or the bias voltage or the headphone itself (leaking bias voltage).
I just tried plugging the energizer into the mains via an extension lead with 'surge protection' (not exactly sure what that consists of) which has lessened the noise somewhat. Doesn't that suggest dirty mains voltage is the culprit and could be remedied with the iPurifier?
 

bobbooo

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#31
Given all the really excellent DACS retailing for $125 or less Amir has already reviewed, why would anyone spend that same amount to improve the performance of their POS Dac.
If like me, you're using electrostatic headphones, the cheapest option for an energizer upgrade is many times more expensive than a DC filter like this iFi device.
 

Nango

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#32
If like me, you're using electrostatic headphones, the cheapest option for an energizer upgrade is many times more expensive than a DC filter like this iFi device.
You spend 100$ on such an enhancement and it sounds great, glorious, excellent, but you spend 1.000$ on that and you'll hear how angels sing, no matter what @amirm says or measures!!! and furthermore you can spread out your Bible thru all the forums!!!!!
 

solderdude

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#33
I just tried plugging the energizer into the mains via an extension lead with 'surge protection' (not exactly sure what that consists of) which has lessened the noise somewhat. Doesn't that suggest dirty mains voltage is the culprit and could be remedied with the iPurifier?
I would power the Koss standalone (so only mains fed and headphone connected and listen for noise.
Then pack it all in and take it along to someone else's house and check again before buying anything.
 

bobbooo

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#34
You spend 100$ on such an enhancement and it sounds great, glorious, excellent, but you spend 1.000$ on that and you'll hear how angels sing, no matter what @amirm says or measures!!! and furthermore you can spread out your Bible thru all the forums!!!!!
I'm not sure what your point is. I paid $270 for my Koss ESP/95X headphones from Massdrop, which included an energizer/amp. They're probably the best headphones I've heard, except for a bit of noise, which I was wondering if I could fix with a DC filter (not necessarily this iFi one, maybe there are cheaper alternatives), without having to spend extortionate amounts on an energizer upgrade.
 

bobbooo

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#35
I would power the Koss standalone (so only mains fed and headphone connected and listen for noise.
Then pack it all in and take it along to someone else's house and check again before buying anything.
Thanks for the help, I'll try this.
 

Nango

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#36
I'm not sure what your point is. I paid $270 for my Koss ESP/95X headphones from Massdrop, which included an energizer/amp. They're probably the best headphones I've heard, except for a bit of noise, which I was wondering if I could fix with a DC filter (not necessarily this iFi one, maybe there are cheaper alternatives).
You were wondering why people buy these PSU enhancements. Some believe the more they enhance, the better it sounds, no matter what other say or may prove it is non-sense.
 
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#38
Thanks for this - really useful to have concrete proof of this for laypeople like me.

Speaking of powering a D50s, any chance of reviewing the P50 power supply? I have zero belief it'll improve sound, but for those of us powering a D50s, an A50, and a Chromecast Audio or other USB powered device it certainly seems a neater solution than multiple switching supplies. Just knowing that it doesn't make things worse would be useful.
 

mhardy6647

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#39
I don't even know how to hear air, microdynamics or resolution. What do they sound like?
Microdynamics and Resolution -- probably like PRaT.
:cool:

Now... air... that one I can grok.

1578608763129.png


(only thing missing is the unicorn)

and then, of course, there's thick air.

Relations between the band and producer Dave Hassinger broke down when Bob Weir requested the ambient sound of “thick air.”
Having produced the band’s debut, Warner Bros. staff producer Dave Hassinger was drafted in to record its follow-up a few months later. But with the band exploring decidedly more experimental territory on Anthem – not least telling Hassinger they wanted to record environmental audio of both the desert and the city – the producer jumped ship. “I was describing how I envisioned the song, and [long-term Dead sound engineer Dan Healy] and Hassinger were hassling over something,” Bob Weir said in Oliver Trager’s 1997 guide The American Book of the Dead. “I announced, ‘Right here I want the sound of thick air.’ I couldn’t describe it back then, because I didn’t know what I was talking about. I do know now: a little bit of white noise and a little bit of compression. I was thinking about something kind of like the buzzing that you hear in your ears in a hot, sticky summer day.”
https://www.rollingstone.com/music/...of-the-sun-10-things-you-didnt-know-2-700628/

1578608913678.png


Not sure how the iFi DC Purifier would handle thick or curved air, though -- perhaps this should be revisited?

:rolleyes:
 

Degru

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#40
Briefly considered getting something like this for USB to use with my fiio a5, which does indeed show audible noise from crappy USB ports depending on how bad they are. But I can reduce noise to inaudible levels just the same by using a quality wall charger or battery bank.
 
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