iFi Audio iTube

General Information

A specially‐developed active Class A tube buffer/pre‐amplifier with two active correction circuits dedicated for digital and analogue audio sources, including the 3D Holographic Sound® system and the Digital Antidote Plus® circuit, in order to bring the "magic of tubes" to any music playback system.

Latest reviews


Pros: Neutral, clean, smooth sounding, great impedance matching, no more digital glare, enhances speaker experience
Cons: None
As a beginning, I would like to thank Owen and Karina from iFi iClub for lending me this product.
To provide some solid base, here I leave you some information about my music tastes and my brief journey in audio.

My journey in audio started in 2012, when I bought my first IEMs, the Brainwavz M1, replacing my damaged Samsung ones (included with a Samsung Galaxy S+). I had been happy with these for a year, they had a slightly warm balanced sound but unfortunately they broke. In 2013 I got into much better IEMs, the VSonic VSD1LE, that although they were outstanding for the price regarding detail, I never liked them too much due to its excessive sub-bass.
2014 was a clear milestone in my journey. I bought my first full-size headphones, the Takstar HI2050, which I still enjoy every day, an entry-level USB DAC-Amp that suited me well and my first high-end IEMs, the VSonic GR07, that I still love. Later on I started testing some good audio gear supplied by Zococity like FiiO X1, X3 and the lovely iFi micro iDSD whose I made reviews for reproductormp3.net (in Spanish, sorry :/ )
Now, 2015 has been my starting point into Hi-Fi.
I started this year with a magnificent iFi micro iDSD and a 2TB HDD to fullfill with tons of music. I began to value having a computer audio setup properly optimized to get the best out of my music. That was my goal.
I installed foobar2000, collected a good bunch of lossless music and changed my music manners. I switched from listening music spontaneously from YouTube to spending long nights with my HI2050 and my micro iDSD. During this whole year I continued testing audio devices (thanks to Zococity) and gained experience writing reviews and improving my critical listening habilities. FiiO X5, X5II, E12A, Westone W50, iFi nano iDSD, iFi nano iCAN, HiFiMAN HE-400, HE-400S, RE-400, RE-600... a lot of stuff! And about the latter, I fell in love with them and stayed with me.
Month by month I continued tweaking my foobar2000, customizing the UI, adding custom tags... Everything to make this experience better.
But actually, the biggest step happened with those RE-600, who took me a long time to appreciate, because they changed my perspective about music, texture and about how music really sounds. I discovered a lot of hidden details in music and learnt about mastering and dynamic range. The more I listen to them, the more I love them. As you know, good audio is very rewarding.
But oh, when october hit me... I won an iFi micro iUSB3.0 in an iFi competition! It revolutionized my audio setup and my perspective regarding electronics, cables and noise. Investigating about this subject, I learnt about the importance of USB cables, good power supplies and personally I did a hell ton of analysis to fix problems in my setup.
Now into this year, 2016, with a wider musical kwnowledge base, centered in well recorded music like jazz and SACD material it's been a great year. My goal has been achieving a noise-free audio setup, to be able to enjoy more detail at a lower volume in order to take a good care of my ears. It took me a long time learning about ground loops, cables, conexions, audio setups analysis but it has been definitely worthy.
I ran a homemade server with a Raspberry Pi 2 to get my noisy HDD out of my room, installed a trusty Cat.5e network cable and began into speaker setups with a pair of JVC SP-UX2000RGD (of 1996!) made in cherry wood that sounds wonderfully. Currently I am also learning about acoustics, speaker positioning, sound isolation, cables (yeah, it's never enough hahaha), materials, properties and improving my analytic capabilities.
And about my sound preferences: I like a balanced sound with life-like texture. As a musician, I care a lot about texture and time precision without forgetting an ample soundstage. I love detail but as long as it does not sacrify any of the given points.
I hope you this helped you understand my brief journey into this world and know better my point of view :wink:
Now, into the review, don't you love its warm orange light? I'm in love with it.

It comes packed in the famous iFi case, sign of "micro" range, with the same finishes as always. Robust switches, gold-plated connectors and their own-designed potentiometer improving the so acclaimed ALPS.

A nice quality board, with 4 layers and top notch rails and great quality resistors and capacitors. Such a beauty!
If we look at it upside down, we can see 8 DIP switches that allow us to select the gain (0dB/6dB) and whether using it as a pre-amp or as a buffer with the help of a flat screwdriver (like the one included). 
I already put the silicone feet to use it in my table more confortably but to my surprise, they changed them in favour of some smaller ones with an elegant logo. With these I no longer can workarround a way to stack them. But, in any case, for stacking iFi micro/nano devices, iRack is the best choice.
This little gem takes about 20 seconds to wake up, that's how valves work. I encourage you to wait until it is ready (look at |> led indicator).
We plug two pairs of RCAs as input and output and we are ready to rock. I have used the included cables by iFi which offer a respectable quality. No complaints.
It is now the moment when magic breaks in, mildly sparkles the elegant and impressive General Electric 5670, also sold apart by iFi for 6922 socket valve devices making use of a tailored ceramic adapter adhered to the valve. Top notch stuff! (More info here http://ifi-audio.com/portfolio-view/accessory-nos-6922-2/ )
Speakers engaged, we crank up the volume and we get lost in music... Guitars sound uncompressed, the piano flows dynamically, voices gain texture... Overall a nice effect.

I'll try to get into the reasons why this improves musical joy:
First, considering it is an active buffer/preamp, some of the spice comes from the 9v iPower SMPS (Switched-Mode Power Supply) which powers this 5670 with very low noise (1uV). Power supply improvements affect noise floor and dynamics.
The second reason of improvement is impedance matching. With its enormous input impedance of 1 Mega Ohm when used as a buffer and 100 kilo Ohms when used as a preamp, it fixes any possible impedance mismatch between source and amplifier
But let's get into business, we are here for the vacuum tube. It's been said by many audiophiles that tubes introduce distortion (harmonic, but they do) in an excessive manner but on the counter-part, tube fans claim solid state sounds unnatural due to odd-harmonics (IMD). So, who is right? Both! But in this particular case, iFi has deployed a very neutral and clean tube, with very low levels of harmonic distortion. The sound we get out of it is almost no colored but it provides a smooth musical experience, helping with some compressed recordings and staying true to original with uncompressed well recorded tracks.
Bass feels more real and has a slight bit more of dynamic. Overall, it has better texture.
Mids flow wonderfully, giving a very pleasant experience. Very smooth.
And highs stay neutral but less fatiguing when using bad recordings.
But I can assure you one thing, you will enjoy your music with this bad boy. For granted!

As a side note, I want to mention that Digital Antidote+ helped me masking out a "compressed sound" problem I had with the USB cable I was using with my micro iDSD. Fortunately I have already changed it in favor of an Oyaide neo d+ USB Class S, which not only solves this but improves SQ noticeably, but this is another topic... With this cable, this feature does no longer add a significant improvement with my micro iDSD (I think it does something similar to Minimum Phase filter, correct me if I am wrong)
And the last feature worth mentioning is 3D Holographic. It provides an outstanding improvement with bookshelf speakers, making them feel more spacious and bigger sounding. There are two modes: Low (*), for HiFi speakers, High(***), for bookshelf speakers and off. So you can find the one that suits you best. I used High(***) mode.

As a recap, this device is a nice addition to almost any setup, from Mid-Fi to some pricey Hi-Fi. Adds smoothness and joy to your music, pleasure is guaranteed!
I will leave you some more photos for you to enjoy 


what a cute JVC micro system, like a little sweet cookie
@Bansaku Thank you! I am quite sure in some point in time I will acquire an iTube. I really liked it!
Which devices do you have?
@FastAndClean Yess it still sounds marvelous even with its built-in CD player. It has 20 years on its back but aged very well!
I am in love with these sweet speakers and their crystal clear mids.


500+ Head-Fier
Pros: Gives you extra "comfort" & enjoyment while actively listening. Songs/tracks that would "wear on you" become more tolerable for longer. (Fatigue)
Cons: Only "CON" isn't really a CON in that it doesn't make a "Night and day" difference to the sound as many may expect. You have to listen for it...
Product name: iFi Micro iTube Tube Buffer/Tube Pre-Amplifier
Manufacturer: iFi
Cost: $329 US dollars.  Provided as a courtesy via iFi Customer Service for evaluation with my currently-owned (All Purchased) iFi equipment .  No incentives given or accepted.
Reviewer: Ken Norris - North America, USA, New Jersey
Reviewed: March, 2016
So, a little over a year ago now, I bought and reviewed a USB DAC from iFi called the iDSD Micro.  Spoiler:  I LOVED IT!  While I am admittedly a relative newcomer to seriously pursuing the ever-moving target known as "Audiophillia", it seems that I have fairly decent luck when it comes to picking people to learn from.  After listening quietly for quite a while to what others who have gone before me had to say, I took the plunge and haven't looked back since. It also turns out that the iDSD is just one device in a whole lineup of products that are designed to work and fit together as the "Micro line" of iFi components. After evaluating the iDSD, and iCAN, I now turn my eye (and ears) towards the iTube in this review.  So what is it?  The iTube is a valve pre-amp that is designed to work harmoniously with the other iFi Micro devices.  I also learned coincidentally, that it works equally well with other brands, but the form-factor is quite literally MADE to fit with the other devices in the iFi Micro line which just makes the whole audio stack affair look so "clean", that even my wife who HATES clutter/wires/gadgets admits that the lineup looks like some kind of industrial art centerpiece.  (Fair warning, I added some "cable management" to tidy-up the power cords!)  To me, a major benefit of the entire MICRO line is that I get serious, full desktop-sized component performance and sound that doesn't ACTUALLY take up a whole desk!  (All 3 MICRO components fit neatly in my backpack or laptop bag for my "on the go" lifestyle.)
The review:
For starters, the iTube that was shipped to me courtesy of Owen & Karina D. (Rockstars in customer service) arrived in the same iFi-Standard packaging as the iDSD & iCAN did. The box dimensions are all identical which makes for easy bulk-wrapping if giving the set as a gift.  (Very thoughtful!)  
Layout - On the front panel is a volume knob and a 2-position switch for Digital Antidote Plus® and another for 3D HolographicSound®.  On the rear panel there are two pairs of RCA jacks for analog audio input and output.  The power socket is on the right-side panel (Looking from the front), with the power supplied from a wallwart power supply with integrated iPower technology to reduce signal interference.  As a nice touch, an L-adapter cable is included so that the power cord doesn't have to stick out of the device at a 90-degree angle!  Underneath there are the pre-amp/buffer preset DIP switches that allow you to select operational modes. This allows you to not only determine how the unit passes or modifies signal, but also how much of an influence the tube/valve circuit will have on your end sound.
What does it do?:
The iTube contains two primary switchable circuits. The first is the 3D HolographicSound® system which provides to my ear, a more 3-dimensional effect to the music and slight highlight of soundstage separation.  The second switch is called the Digital Antidote Plus® whose purpose is to soften any harsh, "ringing" digital sources which contribute to "listening fatigue".
Does it work?:
In my trials, I primarily used the iTube in series with my iDSD as DAC, RCA'd to the iTube, through to my iCAN.  I sometimes substituted-in my Schiit Audio ASGARD 2 or my ONKYO HT-R693 (Via Phono RCA-in jacks) as amplifiers.  Beautiful in every configuration.  Most importantly, I switched-off between my iBASSO DX90 (Coaxial digital signal into the iDSD) and my Home Theater PC (Windows 10 i7 via USB3 digital signal.)  Why most importantly?  Because I was sampling digital audio files ranging from low bit-rate MP3s through DSD128 via straight digital SPDiF & USB transport methods.  If there is anything that I've read that can indicate a cold, sterile, or harsh sound, it's a pure digital setup amped by solid state.  Now does it ever happen to me?  Heck yes!  I've got an abysmal sampling of Foreigner's "Agent Provocateur" that I ripped from my CD back in college back in the 80s that is my personal BENCHMARK for horribly-sampled sound. Scratchy sound quality with grossly-obvious artifacts throughout.  Even my Sennheiser HD-650s were unable to make it sound good!  Now am I going to tell you that the iTube made it sing like a choir of angels?  NO.  What is lost in sampling can normally never be brought back.  But the inclusion of the iTube DID make the darn tracks sound "listenable".  (Think of going from an old, static-laiden AM band radio to a decent mono FM radio.  Still not what you are used to, but definitely a sight better than what you had!)
So, WHY did I start with that example?  Because the point is that the iTube is a very transparent component in the audio chain. It didn't matter if I was using it in pre amp mode, buffer mode, or even with the effects on, the music remained clear, clean, and mostly unaltered. I ran bit-perfect all the way to this device, and it never did anything weird or unexpected to the sound. So I say all that about the worst-case scenario above because it was the only way that I could CLEARLY tell the difference between before & after with almost no effort.  (And I was using Beyer-Dynamic T1 ver. 2s, & Sennheiser HD-800s to check!)
Under "normal conditions" I listened to, and loved some sample  tracks that were recorded in NATIVE DSD128 from InterDA Music (http://www.interda.com/)  These "LIVE" recordings allowed me to examine everything from side conversations in the audience, to the scrapes on the floor as instruments were shifted and moved during performances.  TONS of detail.  Not much by way of sibilance, but when you can hear air moving, you know when you're losing detail due to masking.  With the iTube in or out of the chain, I still heard ALL the effects!  It was to me, the difference between a strong knock on your door that startles you, and a strong knock on your door that you are expecting.  No less loud or crisp, but not as jarring.  (There is an audience member who yells, "Whoo!" in the very beginning of the track "Light My Fire".  You can still hear her and others make various sounds in the background throughout the song, even when the brass do their staccato hits.)  Is it harsh with all that detail?  No.  But it just sounds slightly more welcoming, and enveloping when the iTube is in the audio chain.  And that is the point.  SLIGHTLY.  Not night and day, but if you are actively listening, the added warmth IS there to enjoy.  And I do!
Equipment:  Sources - iBASSO DX90, Samsung YP-P1, Dell XP 8700 (i7, Win 10, Foobar 2000 ver 1.3.5, JRIVER Media Center 21, TIDAL (Client & Browser players), Amazon Music Player, VLC Player, Groove Music Player, & Windows Media Player) Apple iPad Air (ONKYO Player App), Apple iPhone 4S, 5, & 6 phones (ONKYO Player App)
DACs - FIIO e17, iBASSO DX90, iFi iDSD, ONKYO HT-R93
Amps - Schiit Audio ASGARD2, iFi iDSD, iFi iCAN, ONKYO HT-R693
USB Signal Conditioner - iFi iPurifier2
Cables - Monster HDMI, "Generic" USB, Forza Audio Works Digital interconnect, iFi-provided RCA patch cables
Headphones - AKG K545 & K550, Beyer-Dynamics T1 (ver. 2), JVC ESNSY - HA-SR85S-T, HA-SZ2000, Sennheiser HD-650 & HD-800
IEMs - VMODA bass freq, Sony XBA300AP, Sennheiser Momentum
Would I buy?  Yes.   But bear in mind that I only found value myself when ACTIVELY listening.  (Others may very-well notice more easily than I...)   Would I use it during a morning commute?  No.  To listen to generic "top 40" background noise while doing chores around the house?  No.  I just wouldn't be paying enough attention to notice the difference.  But to relax in my easy chair and just enjoy seriously listening to some truly great music?  Definitely.  Why 4 1/2 and not the full 5 stars?  Well I want to leave some room for the next piece of kit iFi develops that will by all previous examples, improve all of their current offerings considerably!


100+ Head-Fier
Pros: smooth , pleasurable , comfortable for long hours of relaxation
Cons: an addiction.
Having the iDSD Nano & iCAN Nano from them, i was very impressed by the iFi's performance. 
Making me trust my money to them, knowing they can provide what they claim it could, and deliver them so beautifully, sonically.

First thing i noticed when i held the iTUBE in my hand , i immediately noticed it was significantly lighter than the iDSD Nano and iCAN Nano , which felt pretty weird . Then i realised that the iDSD Nanoand iCAN Nano both have batteries in them, making them denser. In my opinion, the denser ones felt more premium as there's a certain quality feel to them.

That aside, the iTUBE also require a 3 pin power source, making them desktop bound.

I ran them as such;
Laptop(FLAC 16/44.1 & 24/192) > iDSD Nano > iTUBE Micro > iCAN Nano > Beyerdynamic T90

Alright , the positive points , upon setting up and warming them up , I took a while to play with the switches to try what each of them actually do to my music , but before I did so , I realised my there’s already a slight smoothness in my music which makes them quite enjoyable .

Flipping the Digital Antidote switch did little difference to my music , in all honesty , I could not hear much difference , but I have heard other reviewers stating that it allows mp3 files to sound better , im not sure , I do not hold a single mp3 file in my music list . Having said, I believed it does “significantly reduces ringing and digital distortion” as claimed by iFi & a placebo effect and trust in iFi has quite urged me to leave it on. If you are going to play poorly recorded file with sizzle, cracks and pops and expect the Digital Antidote cancel these flaws away, it won’t.

Then I flicked the 3D holographic to “wide” & “ultra wide” settings , surprisingly , they were not as satisfying as the iCAN Nano’s 3D holographic on my headphones , they felt different , even if I switched my iCAN Nano’s 3D OFF , and the iTUBE’s 3D ON , it still sounded different , very different. But before I make any conclusions, iFi website did mention that the iTUBE’s 3D wide was meant for Hi Fi Speakers & iTUBE’s 3D ultrawide was meant for desktop speakers. With that being said , it is unfair to conclude that the iTUBE’s 3D was of poorer quality than that of the iCAN’s , I have not tried them on speakers , but again , other reviewers online did mention that they found their speakers to be producing addictingly good soundstage with the iTUBE 3D settings , I decide to leave that setting at “zero”. Again, on headphones the iTUBE’s 3D sounds different as compared to iCAN’s. It is wide, but in a manner perhaps not meant for headphones.

The tube glows red and the aluminium case is warm to the touch and works comfortably well as a finger warmer in the cold. The settings was set to “0Db Buffer” , I adjusted it a few times back and forth to the “6Db Buffer” to compare their differences and noticed the 6Db buffer had a more warm and tubey sound , which I have found to love a lot . This changes the characteristic of the music, making it smooth like a warm cup of cappuccino, extremely satisfying & comfortable, Immediately, I know, this is something which I am going to enjoy for a long time. This is really up to preference but I like the 6Db buffer setting better. Sonically, it does not colour the sound much to make it sound choked, it does maintain its integrity. I’ve tried other critically acclaimed tube amps such as the Ocean Bravo which I feel is too coloured/ choked at the high frequencies & losing some of the soundstage & instrumental imaging from the iCAN Nano’s 3D holographic, since music is about preference, I enjoy the iFi iTUBE better as I moved to tubes, from a full solid state setup. But in all seriousness, if you haven’t got the iCAN Nano, please do get it. The performance is superb.

Speaking of those little white gain switches at the bottom. I broke my number 5 switch which is one of the switches that sets the 0db & 6db buffer. This was the only flaw I’ve discovered and was quite disappointed, however I will be heading down to one of their distributors which I have purchased them from to see what can be done to it. Other than that, the construction quality seems durable & solid. 

I've changed the iTUBE for a new one today & redeemed warranty :) now im a happy potato !

In conclusion, this is a very good buffer that makes your music really smooth and enjoyable. If your budget isn’t an issue, this is definitely a tube buffer worth considering. Don’t forget about the iCAN too! 

Here is my setup !

The Campbell coin bank was used to manage the cables :)

iFi audio
iFi audio
@iFi audio the itube is hot to the touch , will the internal components be affected by the internal heat of the itube ?
I ordered an iFi iCan pro and I also have an iFi micro iTube. Should I still chain the iTube in my audio rig? And where should I put the iTube?
Headhone rig: Computer with Foobar2000>RME ADI 2 pro>iFi iCan pro
Speaker rig: Computer with Foobar2000>RME ADI 2 pro>iFi iCan pro>Linn Kairn pro>Norh le amp monoblocks>Focal Jmlabs Electra 946


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