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iFi Audio iUSB : Clean Power Clean Sound

A Review On: iFi iUSB Power

iFi iUSB Power

Rated # 15 in Computer Audio
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Price paid: $199.00
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iFi iUSB reached Earmass!
iFi iUSB reached Earmass!

I have received this review unit of iFi iUSB from Vince few weeks back, and I used it extensively with my rigs. It is indeed a sin for me to enjoy the iUSB so much but delayed the review for so long, in fact, I intentionally delayed this review because lately I have bunch of DAC and Amp arrive at Earmass, so I think this is a good chance for me to truly test the iUSB, after some extensive use, I can say I am positive with what iUSB have achieved in sound.

Why you need a ‘regulator’ for USB?

From Left, a Power supply input Jack and, ISOEarth toggle switch and USB input.
From Left, a Power supply input Jack and, ISOEarth toggle switch and USB input.

iUSB is selling for 199USD and I am sure most of you are questioning, why should we need a external regulator or power conditioner for our USB port? And is this all matter?

If you are an audiophile and you have some room for your budget, I will says good sound is not only about how good or expensive is your audio equipment, synergy or matching, but every components and process in your audio equipment do count, they are all equally important in role playing to me. You can’t expect a good spaghetti with a bad sauce mixed with good ingredients, or with a bad cook. Same thing goes to audio equipment, a good power supply/source is very important, this is something that we often overlooked when setting up our audio system.

iFi iUSB explanation

I can’t provide any technical data for you nor frequency chart, but a cleaner and stable power source is every important. For home audio/theatre system, they often used a AVR (Automatic Voltage Regulator) for generate a clean and stable power. Nothing is difference for the headphone system, our DAC and amplifier need a clean and lean power source as well.

Packaging Box

Worth to get one? Definitely
Worth to get one? Definitely

Unfortunately our USB power supply from computers is always unstable and dirty. This is why iUSB exist in the market. I have been long time searching for something like this, a truly good regulator for USB. Yes it is quite true that our computer USB provide a 5v output for devices, but have we ever think that is this real? I have read from some place that our computer (Especially the budget one) is not cannot constantly provide the 5V for u, and there is another section (Sorry can’t provide you more as there are too many scientific terms that I don’t understand) that straight USB from computers are bad to.

Description and Operation


You will get a good quality PSU adapter along with this iUSB and you needed that to supply the power for iUSB, and a USB cable to iUSB for sending information.

Means, in order to make iUSB work, you have to:

1) Plug USB cable from your computer to USB input of iUSB.

2) Plug power supply unit from included PSU adapter/ USB power supply (Also included in the package).

Then you can connect your devices to output of iUSB. I am sure that you have seen there is 2 types of output on iUSB which is output for Power only and output for Power + Audio. Let me explained these in layman term.

I switched on the IsoEarth all the time except that there is one time it can't work with my device. An empty battery XDuoo XD-01, however when it has some power cell inside the battery, it worked fine even I switched on the IsoEARTH.
I switched on the IsoEarth all the time except that there is one time it can't work with my device. An empty battery XDuoo XD-01, however when it has some power cell inside the battery, it worked fine even I switched on the IsoEARTH.

1) Power Only : means you can plugged in the device that require no interaction with computer, such as USB phone Charger, Charging your music player (But cannot transfer file, just charging),  mainly just for anything that require power to charge/power up them but require no interaction/information transfer with your computer.

2) Power + Audio : These will be used for DAC, file transfer (Thumbdrive, Hardisk, Mouse and keyboard), and it can also function as like ‘Power Only mode’.

What I wished and praying for are 2 Power + Audio output, as this will work way more versatile and convenience. However this is considered reasonable though. It is just that if iFi Audio made both of the output that can communicate/transfer file with computer, it will surely better, especially when I connected my DAC and Hardisk together to my computer.

Sound Changes?

Well, the most important and decisive factor is still sound quality, and is iUSB helping DAC to sound great. For short answer, YES and improved by a big scale.

How often am I pairing my devices with iUSB? To be frank, I am using this iUSB all the time since I got it. For me sound differences are just obvious, and I wish just the best from my system. Every time when I want to plugged in my DAC to computer, I always find iUSB as my companion, not a single time missed.

Tried iUSB with iFi iDAC and iCAN

I called them 'The Triad'
I called them 'The Triad'

I have tried the iUSB with iCAN and iDAC, forming the team that I called ‘Triad’, I played La Campanella (Diabulous in Musica by Aerpr), with iUSB added into the combo, I can heard more details and also seems to have more energy. Instrument are sounding more real, for example violin sound lean and textured, triangle sounded crisp. The differences are quite obvious if you noted how the instrument sounded, with iUSB instrument sounded leaner and cleaner, and much more real in comparison with better body.

When I listened to vocal in some songs, the ending nuance of vocal is much more present and expressive when I paired with iUSB. The piano sounded muddy without iUSB in comparison. Adding in the iUSB do improved sound further.

Tried with Audinst HUD-mx2, XDuoo XD-01 and JDS Labs Objective DAC

Sound is definitely cleaner, leaner and fuller with iUSB. I played Hotel California (Hell Freeze Over by The Eagles), I can hear every nuance and plucking of guitar fuller.

I tested with some vocal tracks, same as the ‘Triad’, vocal has more space to breath, expressive and fuller (Nuance) than without iUSB, everything has better clarity and richness. Bass is filled with texture.


How about Yulong Audio U100 and D100 II?

Same casing as iCAN and iDAC, I have no problem with the design, tough and elegant
Same casing as iCAN and iDAC, I have no problem with the design, tough and elegant

U100 and D100 II are different device, becaused they are powered by external PSU or power source, unlike those power supply is directly from USB port, however I have noticed some improvement although not as subtle as previous setup but differences are definitely there.


Worth to get one? Definitely
Worth to get one? Definitely

I can’t say just go and buy this now as everyone has different perception regarding the sound that one is after, but for me I will just get it, because I seek clean power source as an important factor that can definitely improving the sound, and a constant power supply do prolonged your audio devices too.

If there is anything that I wished can be improved it must be adding one more Power + Audio output, this will make iFi iUSB a better bargain.

On the boxbeside my laptop

Anyway, the improvement is subtle, you will get better high, mid, low, space and speed with iFi iUSB, this is a good thing and when you have clear power for your DAC, then you just should start to look at a better DAC, if you love how your DAC sounded, then get an iUSB instead, you will love your DAC more.


Nope, this is just another "hi-end scam".
Doesn't sound like a scam to me.
Unlike funny rocks or little dots, there actually is some Engineering behind this.
Oh, wait.
This is the internet, everyone thinks they're an expert.
Cable Inventory
Kimber KCAG interconnects
Nordost White Lightning interconnects
some homemade stuff
some Monster Cable digital
No wonder it doesn't sound like a scam to you?
I don't mean to offend, and I think you're not taking me quite serious anyway :) But i'm just not one who believes in this kind of products.
best to reserve judgement till after you have actually heard it.
Agreed, I wouldn't put my money on this either unless some one brought it to a can jam and I could HEAR it with all of my own gear, in addition look how the review is written. It reads like an advertisment and seeing as the fellow who wrote it has a "review site" I smell a profit being made here maybe. Non the less the concept is valid. That power reason is exactly why I use USB 2.0 instead of 3.0, 3.0 is regulated for more power out so my dac get's TO much and sounds bad, where as 2.0 does not run as much power ect... ect...
Non the less props to you for writing it I suppose, in addition
like cusomt nuts said, "till you've actually heard it"
Yes, the concept is valid.
SMPS (Switch Mode Power Supplies) often conduct and radiate a fair amount of noise.
Even linear power supplies create noise when the AC is converted into DC. It is a fact of life. You can't get rid of it, you an only reduce it down to an acceptable level. When the computer designers specify the USB power supply they are not thinking about you, they are thinking about $$$.
After working in an Engineering Dept. along side SMPS designers for 11 years I may actually have a bit of insight into this. ;)
Does this thing work?
The final, definitive answer is: it depends on how much noise your source USB creates and how much noise your load USB device filters/rejects.
Question: if the price of this box is "only" 175 pounds, why is it not included in the design of any hi-end dacs?
Lol, I am just about speechless to hear all of these.
First of all, I am not making any profit out of all of the reviews I have ever written.
Secondly, the iUSB do give better sound, the significant changes is the 'nuance' and fullness of music.
Third, There is some issue with USB 3.0 to work with iUSB, it will caused some noise, in iFi iUSB,iDAC and Musical Fidelity Vdac II.
I just want to say, before you really hearing one of these, don;t ever came to conclusion that this is a scam or something, I heard the differences so I just stated that in the review. I am not denying anyone, just trying to clarify myself. And honestly, no single cent of profit that I have earned over this, it is truly a demotivate phrase that I have ever heard.
Anyway, thanks for the input, and sorry it took so long for me to reply here.
Headzone : Power supply for DAC/amp is always important from day one, that is why in some high end stuff there is another separate unit of power supply, clean power source prove the sound most of the times.
So this is why we can see some audio equipment manufactured power regulator and power regenerator to make sure the DAC and amp has clean and sufficient power supply, I have heard those and I can say it is actually improve the sound by much.
Now come back to iUSB from iFi Audio, it is more or less work in the same way, I have also said in my review, when I paired with device that has separate power supply unit, the difference is not big.
I am in Engineering field as well, however, for sound and audio, there is no TRUTH until you have really heard them.
I understand Headzone's skepticism, because I too have experienced so-called audio tweaks, cables and components that supposedly make the sound better but didn't (at least not to my ears). However, after auditioning the iFi iUSB with my system, I can safely say that it is NOT a scam. After less than 10 minutes of listening, I decided to buy it and keep it in my system. For less than $200, it is one of the best upgrades I've made to my audio system in terms of value. The sound has become noticeably - yes, I really mean it - less veiled and more transparent.
There are a couple downsides: I can now hear some sibilance in treble-hot tracks which was relatively "smoothed out" with my tube amp. Also, for some weird reason, I feel the volume has decreased. To enjoy music at my usual listening level I have to turn the volume knob up. This isn't a bad thing really, as the sound becomes fuller and increases in soundstage as it the volume knob gets closer to max volume. Other than these minor issues, I'm very happy with my iUSB.
ifi have turned out to be great little products with high value as many reviews around the world have shown. Just highlights the ignorance of people who speak before they think, or should I say understand. Btw, thank you for taking the time to write the review, it's much appreciated by many and is a huge part of what makes this community.
+1 to customNuts
^^ i will try to get one ASAP :D
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