iFi Micro iTube2 Vacuum Tube Buffer and Preamplifier

Average User Rating:
  1. jinxy245
    "Lush and Lovely"
    Pros - Works as advertised
    adds smoothness without sacrificing clarity
    usable filters
    can be used for speakers and headphones
    Cons - niche market
    runs hot (to be expected but potential negative)
    value needs to be weighed individually

    Anyone that has been around this hobby for a while knows that there are many different things that influence the quality of sound we get from our gear. Countless articles are written about different amps, dacs, ear tips, ear pads, cables, etc. and the added nuances they can bring to the listening experience. All of these items have a primary function, ear comfort, isolation, signal transmission, signal conversion etc., with changing the sound supposedly being a secondary benefit. The ifi iTube2 is the only piece of equipment other than an equalizer that I can think of whose primary function is to alter sound,. It’s an interesting component that I likely would never have had the opportunity to hear; so my thanks go to Lawrence and ifi for organizing a tour for the Micro iTube2. For those who are unfamiliar with review tours, I receive no compensation other than my time with the review unit in exchange for my honest opinion to be posted here.(please forgive the images, which were all borrowed from the internet)

    So what is the Micro iTube2? To paraphrase the ifi website,

    “The micro iTube2 is a tubed output stage, tube preamp, tube buffer AND an impedance-matching device all in one. There is nothing like it. You can put the micro iTube2 before a solid-state preamp and another one after it, creating the effect of tubing the whole audio chain. Or you can choose to simply use the micro iTube2 as a very high-quality preamp by itself.”

    So it seems the iTube2 is created to impact the sound by adding a tube filter into the signal path. Whereas an equalizer targets a specific bandwidth, the iTube2 is geared more towards the overall tone, although it does have some equalizing properties. At first I was quite intrigued with the idea of adding the ‘tube sound’ to my setup. Then I had some doubts…it seemed a lot of trouble to go through for a ‘tonal shift’ if you will, and I wasn’t exactly sure how to integrate the iTube2 into my setup, so I originally decided to back out of the tour (more on that later). Finally, curiosity won out, and I asked to be included once again, and I can honestly say I am glad I did.

    This is, to my knowledge, a unique product. I have heard of tube buffers and the like in guitar set ups for performance or recording, but not in the audio community. The iTube2 can be configured either as a preamp or as a filter between just about any source and an amplifier. I wasn’t able to run the iTube2 as a preamp in my 2 channel home setup, which was one of my hesitations in participating. Since it can be inserted into a headphone audio chain, that’s where I concentrated my listening, with pleasing results. Obviously that’s where my review will concentrate, and I’ll do my best to touch on some of the relevant features, as well as give my impressions of how much the iTube2 impacted my listening experience.

    Anyone familiar with the ifi line of products will recognize the shape & layout of the iTube2. On the front from left to right there is the 3D Holographic+® matrix control used for Speakers (off, default & 30˚+), the Xbass+ control (OFF, 20 Hz [+6dB] and 20 Hz [+12dB]), the Tube+® circuit which selects the ‘sonic flavor’ you want ( Push-Pull tube power amplifier, classic tube amplifier, and Single-Ended Triode [SET] power amplifier) and a volume knob which presumably is only functional when set in preamplifier mode since it had no impact during my use as a buffer.

    On the rear you’ll find the input/output RCA jacks to connect the iTube2 to your source and amplifier, one side has the power input for attaching the charger, and on the bottom are the ‘dip switches’ for configuring the unit’s output as a preamp or a buffer, and the various adjustments to those settings. As confusing as those switches seem to be, there are only 4 settings listed; 0db & +9db as a buffer, and 0db & +9db as a preamp. There is a handy diagram for setting them printed on the bottom of unit for quick reference.
    ifi Dip switches.png

    In keeping with my experience with all ifi products, the iTube2 is built solidly, although it is lighter than I might have expected. The knobs and switches feel solid, and the traditional ifi silver finish is quite attractive IMO. The accessories are fairly sparse, with a charger, ifi’s trademark purple RCA jacks (a unique cord color I haven’t seen anywhere else), a mini screwdriver (presumably for changing the tube), and I believe a right angle plug, which wasn’t in the box I received, so I won’t comment on it (things do get lost in transit on these tours). Sparse in this case is not a negative, because all the essentials are covered and there’s not much more I’d expect to find. I imagine there are no stacking bands because the Itube2 does run a bit hot (common for tubes) and benefits from having good ventilation. (ifi does sell a stacking rack made for their products, info here: http://ifi-audio.com/portfolio-view/accessory-irack/ )

    My major hesitation in participating in the ifi tour is that all the dacs I own are integrated (Hugo V1 & Dragonfly V1.2), so the iTube2 would have to be utilized between them and another amp. I thought that it might be interesting to try to run an RCA to 3.5mm cable from the ifi’s outs directly to some headphones, but I was informed that the iTube2 is NOT intended to be used as a headphone amp. One of the benefits listed for the iTube2 is as an impedance matcher, so as far as I can tell that benefit is only to the input of whatever amp you’re using. Regardless, I settled on using my Hugo to the iTube2 to my ALO Continental after my source (either directly from my computer via USB, or from my Shanling M2 by coaxial). The headphones I used were my ZMF Eikon and Sennheiser HD600.

    I have to say that once I stopped trying to figure out the best hook up and let myself simply listen, I began to really enjoy my time with the iTube2. Keep in mind that there seemed to be no way to feasibly test my setup with & without the iTube2, so my impressions are in no way scientific. My conclusions could be conformation bias, but I honestly don’t think so. The difference was audible to me, and I stand by what I heard.

    Although it seems these settings were engineered for use with speakers, they worked fairly well with headphones as well. The Xbass I found to be very well implemented. At 12db the bass was really thunderous yet I was surprised to find it wasn’t overly distorted with my ZMF Eikon. When set at 6db there was still a very effective boost, and even though I did most of my listening set to ‘off’, I found myself indulging in a bit of basshead pleasure from time to time, with both the HD600 and the Eikon. The 3D+ had a more subtle effect with headphones. I found any change to be concentrating on the treble, adding some clarity and ‘air’ with certain recordings (not very noticeable on others) which I found to be particularly pleasing with my Eikon. I don’t recall ever thinking it was too much.

    Of the different tube modes, my favorite was the classic tube amplifier. That setting had the best clarity IMO and it sounded the most dynamic. The highs were a touch clearer, the bass vivid and the mids equally present. Both the Push-Pull tube and Single-Ended Triode [SET] softened the sound a bit too much for my tastes, of course YMMV. I imagine each setting could change depending on the audio chain. Describing sound in words is difficult at best, but what I did find overall was a smoothness, perhaps a refining of the edges of the notes. What I didn’t find was a lack of clarity or a decrease in resolution. Everything still sounded ‘there’; I couldn’t pinpoint anything missing. What was ‘there’ didn’t change in tone, or go so far a smearing, but did seem to soften a touch. It was an addictive sound to be sure, and I found myself getting lost in longer listening sessions than I usually would.

    I genuinely enjoyed my time with the Micro iTube2. With a MSRP of $375, it is not for everyone. I’ve heard things like un-digitize, analog-ize and other such phrases that seem a bit over the top to me. I did experience a subtle warmness infused into my music, which once I heard, l wanted to hear more. Value is certainly in the pocket of the beholder, but I can think of worse ways to spend my cash. The iTube2 does seem to live up to it’s promise of adding the often sought after tube flavor to almost any set up.
  2. knorris908
    "Solid State Simplicity Yielding Warm Tubey Velvet"
    Pros - Simple setup, Easy A/B comparison of unaltered signal vs "tubified" sound. Ability to customize audio parameters to suit your current headphones from most any source, rather than constantly swapping headphones during your listening sessions.
    Cons - While still quite portable, not battery powered like the iDSD & iDSD Black Micros for TRUE portability during travel.
    iFi Micro iTube 2 Review

    Problem: I love music. I mean, REALLY love music. There is almost no iteration, form, or flavor that I can’t take joy in listening to given the right mood and environs...

    Secondly, I like like SIMPLE. Call me a victim of the “instant gratification age”, but I would rather plug in my headphones/speakers, select a song, and just be swept away by great sounding music, than spend time picking and choosing different parts, components, and mixing combinations is search of the elver-illusive “perfect sound” that I often see others pursue. Doesn’t mean that I don’t respect those who dedicate themselves to it, (And to some, I might seem that way myself! “Why would you ever need more than an iPhone and the stock Apple ear-buds to hear music Ken?”) but I would rather spend my fleeting spare time LISTENING than constantly chasing an aural ideal.

    Solution: For me, it’s solid state. I enjoy quality components and have tried many, but I almost always come back to solid state. No warm-up, more durable, (Resistant to shock/drops) and lastly, they are typically much smaller than analogue components.

    So that brings me to the subject at hand. I have a number of solid state amps that I use, and I have found my favorite headphone combinations for each. One of my primary criteria after fullness is detail. I love to hear separation and emphasis from each voice or instrument. But some combinations can take it a little too far, and that same lovely detail becomes sibilance, or harshness to the sound. By default, I would simply switch to “warmer-sounding headphones”, but this was usually at the cost of the very detail I valued. Also, what if I only have one set of headphones with me at the time? What then?

    Enter the iFi iTube, and now, iTube 2.

    I can truly say that I no longer have to rotate headphones with certain songs! When the iTube 2 is paired with a less than stellar DAC, there is marked improvement to the smoothness, and when it is paired with a great one, it still improved audio quality, but to a much less noticeable degree. Point being that it never made things worse by being added to the audio chain.

    So what is it?

    The iTube 2 has been out for a while so I won’t go into detail with specs, as they are all out there already. In short, the iTube 2 is an amalgam of a number of advances in audio technology:

    l Start with clean power! - There is an iPower power supply that provides battery-like quietness while still giving AC power benefits.

    l Tube+ circuit - The iTube 2 has a direct tube buffer with selectable sound signatures, (SET, Push-Pull, Classic) and a hi-end preamplifier that banishes digital harshness in favor of a glorious warm and full feel to your music.

    l 3D Holographic + - Ever have that “claustrophobic feel” to your sound that makes you wish your music sounded “bigger and fuller”? This is what you want!

    l XBASS+ - Xbass gives you a more emphasized low-end without introducing bloat or looseness , and without automatically crushing your mids.

    So is it difficult to use?

    NO! Remember when I said that I value simplicity in my audio equipment? Well, this is it. No need to “Tube-roll” by plugging fragile tubes with equally-fragile pins into a base that might not line up properly if you’re not careful and bend those same-said pins. With a simple flip of a switch, you can select “SET” (Single Ended Triode) mode, Push-Pull mode, or “Classic” mode. I tend to favor “SET” with 3D Holographic with my headphones that have smaller soundstage, and without 3D when connected to our 7.1 surround sound home theater.

    Connections? Super-easy! 1 A/C adapter plug on the side. (Round plug so you can’t plug it in “wrong-ways around”.) 4 RCA connectors on the back. (2 “INPUT” L/R and 2 “OUTPUT” L/R) Plug them in with standard stereo RCA patch cables. NOTE: iFi has consistently provided RCA patch cables with their Micro line of products. Know that these are not poorly-performing “cheap cables”. I have compared the performance between the stock purple iFi-provided cables against Belkin, Cables To Go, and Monoprice, shielded “gold-plated” cables, and found the iFi cables to perform just as well!

    Plug your source, (PC, Mp3 player, Phone, DAP, Turntable or DAC) to the INPUT connectors, then plug your amplifier (If using one) or speakers to the OUTPUT connectors. DONE!

    How does it sound?

    Well, From most impressive, down:

    l Lenovo Yoga Android Tablet - (Android 6) Straight, or through DAC, THE most improvement in how smooth, musical, and warm all my music sounded. There is an edge to the audio that I don’t hear from my other devices that makes music sound sharper, but also harsher than any other source I own. Without the DAC, I also hear more audio artifacts, but the iTube 2 helps to minimize their intrusiveness.

    l Apple iPhones (4S, 5, 6, & 7Plus) - Straight, or through DAC, the 2nd most improvement in how smooth, musical, and warm my music sounded. Did magic with old, 128-bit encoded MP3s and nicely enhanced iTunes AAC music.

    l PC USB --> iDSD DAC - Largely improved the harshness of my most sibilant music files without making them sound “muddy”, or lacking in detail.

    l DAP - Straight through my iBASSO DX90 shows the least improvement in how smooth, musical, and warm all my music sounded of all my portable sources. (It’s just THAT good!) With my iDSD Micro acting as DAC, it tends to smooth out any harshness a little more, but that is simply because it is a slightly more analytically-tuned (Precise) DAC than the one in my iBASSO.

    l Sony STR-DN1070 - This took forever! There are so many combinations to choose from. Sony as Analogue: Source, Source & Amplifier, Just Amplifier VS Sony as Digital: Source, Source & DAC, Amplifier, USB, WiFi, & Bluetooth. The Sony pretty-well held it’s ground no matter how it was connected. The main changes were in the selection of DSP options that Sony offers. Some smeared the detail completely, while others (bit-perfect) just laid-bare what was in the audio file. In the case of the former, the effects of the iTube 2 was barely detectable. With the latter, the iTube 2 provided similar performance to what I heard with the iPhones when playing well-encoded tracks, and performed more like it did with the Lenovo Yoga tablet with poorly/low encoded music tracks.

    Should I buy one?

    As always, this is a very personal value that you must weigh for yourself. To me, if you value:

    l Simplicity - Easy to use, “Set it and forget it” with no cumbersome menus to hunt around).

    l Small footprint - Can sit easily on your desk at home or work, or your nightstand at home or in a hotel while traveling.

    l Great buttery-smooth “Tube sound” that you can adjust without swapping parts.

    l Solid construction that can weather regular travel in a laptop bag, suitcase, or carry-on with minimal risk of arriving at your destination DOA.

    Then I’d answer with a resounding, “Yes”!
  3. ngoshawk
    "Tubey gooeyness is as good as tubey goodness!"
    Pros - Easy to hook up and use, adds a "velvety" sound to your music, multiple choices with which to customize your listening, affordable, multi-use (system) options
    Cons - Gets quite hot, but it is a tube-amp, afterall. None.
    iFi iTube2:


    Two wonderful things happened to me on one fine day recently: I found out that I would be first on the iFi Appreciation Tour, and we as a collective had decided the iTube2 would be the representative; AND I perused the iFi iDSD Micro Black Label thread, finding out that I was the lucky one drawn to receive the Unique Melody Martians…Hooolllyyyyy BUCKETS!!! Needless to say, it was a banner day in my humble abode. I was humbled and jumping like a kid given their allowance in front of a candy store. WOW! I am extremely thankful to @Lawrance for his help in this wonderful tour, as well as the logistics of arranging all. Plus, he was very quick to respond when my “doltishness” could not figure out how to hook the iTube2 up. Wonderful, he was, with the help.


    In the week between arrival and testing, I scoured the threads of Head-Fi regarding the original iTube as well as the early reviews. It really was a fascinating read regarding the history of the tubes used, and why they were chosen. Call me a fanboy, but I am a hooked-for-life in the philosophy of iFi. The link provided only gives a hint of the history behind the tubes. Lawrance goes into wonderful detail on the Head-Fi thread itself.



    A little background history…

    iFi iTube (original):


    And the link to Lawrance’s excellent tube history lesson, in 3 parts:


    The basis of the tubes used is their historical use in WW2. They were sturdy, efficient, and lasted a good long time. Put away through historical efforts, iFi brought these wonderful tubes back out for our pleasure. And boy oh boy, did it work. I will trust all of you dear readers, to read all three parts of the history, they are good reads. Plus, I don’t want to spoil all of your fun!

    I have a small inexpensive tube amp, which uses the tubes in the pre-amp phase of the sound, I use on occasion, but this is the furthest up the tube-food-chain I have wandered, personally. Yes, I have heard multi-thousand dollar McIntosh systems (and would love to own a system of such accord someday); but this is the first time I have had such a lengthy audition.

    Upon proper connection, to the iFi iDSD Micro Black Label (henceforth known as BL, because iFi iDSD Micro Black Label takes a bloody long time to write…) and my MacBook Pro, I plugged in my new UM Martian’s. I will say, that it did take a bit for me to dial in the sound to my tastes, but when you realize all of the tuning options on both units, you will understand. I did first run the units flat, without the aid of 3D, or bass boost, so I could have a baseline sound with which to judge. And it was impressive. The iTube2 gave a lusher, more rich sound to the system, immediately. I understand that I was the first on the tour, but the package came open, and I assume somewhat broken in. It will be interesting to see what the followers of me find, with more tube burn in time, if any change is to occur. I was impressed, because I do value sound on the warm side.


    Withholding judgment, I continued to play with the options. I carefully would manipulate the “toggles” on the backside, for whatever “filter” I chose. What a cool idea this is, and it paid dividends in my listening enjoyment. The most used filter was the “Pre amp” filter set at 0dB. I determined, that with the bass boost and 3D switches, I did not need additional input from the iTube2. I did try it, and I could tell a difference volume-wise; but my old ears would be hard pressed to tell a difference sonically between the 9dB push and the others I used, SONICALLY. Hence, I chose the easier path of switching toggles (on the front). It was easy. Initially, the unit came set at “Buffer” 0dB. I changed to the Pre amp after a brief listen, and kept it that way.


    Some general comments from the dedicated thread:

    X-Bass is an active circuit, which can't operate without an active element. The iTube 2 substantially improves the SNR and THD over the older model:

    1. SNR - 119dB(A) @ 2V for iTube 2 vs. 111dB(A) @ 2V for original iTube
    2. THD - 0.009% @ 2V/600Ohm for iTube 2 vs. 0.05% @ 2V/600Ohm for original iTube

    In buffer mode and "Tube" setting (no gain, no volume control) you get X-Bass and vanishing low distortion and noise.
    This circuit is actually about 90% of a single-ended version of the iCAN Pro preamp output.
    And no, it is not designed to drive headphones, though it can drive 300 and 600 ohm loads to high levels.

    Sprinkle the ‘magic of SET’ into any system


    1. High-end Direct Tube Buffer/High-End Direct Pre-amplifier
    2. Selectable tube sound signature (SET / Push-Pull / Classic)
    3. All-new 3D Holographic+® for Loudspeakers matrix system
    4. All-new XBass+® for Loudspeakers matrix system
    5. Pure analogue volume control
    6. Ultra-low Total Harmonic Distortion (THD): <0.009% (Tube+ off)
    7. 0dB or 9dB selectable gain
    8. Reference class parts quality from ELNA Silmic to C0G capacitors
    9. iPower (15V) included, ‘quieter than battery’ power supply
    10. Tube: NOS GE 5670×1


    Technical pdf:

    http://ifi-audio.com/wp-content/uploads/data/iTUBE2 - Tech Note One Why GE 5670.pdf

    Full information, iTube2:


    Delving into the feature details:

    An interesting note is that while the toggle system carries over from other iFi products in this category; the three on the front (3D, bass boost, SET) have three settings each, something my BL does not (only two). So not only can you fine tune and add boost/3D/SET, you can, change all three to add two levels of “additional tuning.” I find this aspect eminently changeable and worth it. I found myself changing bass boost and 3D according to the music and song with which I listened. A nice feature.

    In working out the differences of the SET feature, I found that did indeed favor one, but that will have to wait. In a brief explanation, the three settings


    – a Single-Ended Triode power amplifier;


    – a Push-Pull tube power amplifier;


    – a classic tube amplifier.

    did indeed provide three distinct sounds, such that even these tired ears could fathom the difference and distinct betweenst them. As one review posted, the Push-Pull sounded like an acoustically well-set-up concert hall. To me, the Single-Ended Triode while giving a bit wider sound stage was not as communicative a sound as the Push-Pull. I did favor the Push-Pull and ran this setting for probably 85% of the time. I can concur and state that there was a nice wide concert-hall/acoustically near-perfect church-like sound to it. One in which I very much enjoyed, no matter what headphone I used.

    The 3D toggles provide three setting too: “opt out,” slight offset, and 30 degree offset. Opt out is just that, no 3D setting. The slight offset is similar to the BL offset, giving a wider sound stage as well as a bit more depth and height. Yes, I would call it a 3D sound…The 30 degree offset gives a VERY different sound. One in which the user feels as if the instruments are quite literally switching around, like an old Doors song, almost psychedelically. Maybe not quite that extreme, but I did find, on the majority of listenings that it gave me TOO much three-dimension definition. I felt it colored the outer aspect of the sound too much for my liking. I noticed this even when isolated without the BL settings turned on. With the 3D BL setting turned on, it made the situation worse. I was not as happy with that setting as I thought I would be, so I left the 3D (when turned on) to the middle setting, on the iTube2. I would play with the 3D on the BL, but found it best to leave only the iTube2 3D switch to the middle position.


    McIntosh sound for the home portable

    Once I figured out how to hook the critter up (thanks Lawrance!), the iTube 2 (iT2) started humming away hooked to its brethren, the iFi iDSD Micro Black Label (BL). And, it was magnificent through whatever I hooked into the headphone output of the BL…Grado GH-2, Unique Melody Martian, Vibro Labs Aria, Meze 99 Classic, Auqioquest Nightowl, it did not matter…all were made to feel more like a 50’s McIntosh sound, which to me is a beautiful sound to behold…

    Ummmm.....some initial issues....

    Whatever was hooked simply sung with that familiar warm enveloping tube sound. From the open airy sound of the wonderful GH-2, to the rich vibrant full, muscular sound of the Martian, the iT2 simply performs it’s magic warming all to an almost enhanced tubular sound. And I was glad.

    Comparison/Units used:

    MacBook Pro
    Shanling M1/M5
    FiiO x5iii/A5

    Grado GH-2
    Unique Melody Martian
    Vibro labs Aria
    Audioquest Nightowl
    Meze 99 Classic

    Songs auditioned:

    Ziggy Marley- I Am Human & Dragonfly (live and album version)

    twenty one pilots- Guns for Hands, Trees, Screen, Car Radio

    Bob Marley- No Woman No Cry, Buffalo Soldier, Three Little Birds

    Stevie Ray Vaughan- Look at Little Sister (live Austin City Limits), Mary Had A Little Lamb (same)

    The main listening set up was through my MacBook Pro, BL and the iTube2. I then switched between the excellent loaner Grado GH-2, and my UM Martian. To say I was thrilled, lucky, excited, and honored would be an understatement of grand proportions. I am a very lucky individual indeed, right now.

    Playing Ziggy’s I Am A Human, is just a fantastic synergy of not only culture, but of vibrant tube-loving warm-full sound. With a rich, textured bass that reaches down and plays a very strong foundation, to the support instruments in the mids and Ziggy’s voice taking front and center (but not boisterous) in a reverent tone, the song pretty much typifies what the iTube2 brings to the table, when working with the Grado GH-2. I am thoroughly impressed at the partnership, and do not want to let EITHER go anytime soon…Providing a solid support to the Grado’s forward mids, the iTube2 provided to added warmth with which the GH-2 benefits to fulfill a thoroughly enthralling sound. Sound stage of rich wide proportions, good depth and good height add to the excellent instrument separation heard. I am taken in by the tubular sound, and a throwback to a thoroughly modern version of that excellent 50’s sound through what could pass for a 50’s specific headphone, what with their architecture.

    SRV’s excellent live version of Look at Little Sister, replete with a flawless guitar change due to his impressive string break provides an excellent example of how diversity of sound comes through the iTube2. A simple look back at his roadie, and a flawless exchange ensues. Wonderful to watch, all the while reveling at Stevie Ray’s beautiful guitarmanship coupled with an incredibly versatile voice. His gruff voice can turn sweet melodic on a note; just as his bluesy guitar licks can turn from a luscious melodic, enthralling sound to the sharp staccato of a fast picked beat and almost tortuous (in the best possible way) sound. From one chord to the next, SRV was a master at playing, evident when he lowered by a chord his playing to accommodate the broken string. Versatile would be an insult to his musical nature. Throughout the sound, whether with the Grado, or UM Martian, the iTube2 added a sense of depth and warmth to this song that seemed to not be there otherwise. Instead of the proverbial front row setting, I was transformed into that guitar string. Moved to within his guitar, and seamlessly transferred to the replacement during his excellent vocal solo. I’m not sure what else the instrument of our listening can provide, but to thoroughly envelop us, taking us into our music and losing us in the sound. An incredible synergy ensued, as I replayed the song, over and over listening for that nuanced difference, and detail, which I may have missed.

    twenty one pilots Guns For Hands provided that incredible variation of slow to fast to slow and back to fast juxtaposition of sound, which can be a bear for some audio gear to handle. From the almost painful sound of Tyler’s excellent vocals, to the harsh drumming of Josh, I felt again as if I was inside the music, enveloped in that wonderful sound brought out by the twosome. From the upbeat sound and driving texture of the high parts through the listening combo, to the soft almost mournful parts, I was on edge the first time I listened, and rightly so. It was musical twisting at its best. A throwing of emotions through the iFi combo wrought with a rich texture to be savored. And I did. Layers of depth brought throw simple instruments of drums and piano, supported by the “off stage” instruments played with my emotions and listening. I was a very happy customer indeed. The iTube2, set on the middle SET, bass boost on, and 3D off, brought about this pleasurable listening. The BL brought the power, and both the Grado and Unique Melody’s were the final representation of this fantastic trio. One thoroughly to be enjoyed. This was probably the sound, which solidified my respect for the iTube2. When the instrument of our listening can give that much respect for our listening, then you have found something to treasure. I have said this almost exact statement before, but it is true…when that listening bliss comes through your instrument of listening, then you have reached that level where you can sit back and enjoy the sound. The music of your listening.

    Moving back to Ziggy, his two fantastic versions of Dragonfly provided me with the confirmation that I had indeed stumbled upon a gem. And a reasonably priced, to boot. The live version (used in other reviews, but listed here again, because it is so darn good…) is something to behold.

    The synergy between Ziggy and his supporting cast (especially the guitarist) is one of musical perfectness. My only wish is that the guitar solo, let alone the song would go on for another 10 minutes or so…Alas, I would have to replay it over and over, last night…

    And from that, I was able to discern a certain quality, which separated itself from my other listenings. One of acoustic depth. The perfectness of the two together, is only made more perfect by a subtle but noticeable mistakes within the song. REAL is how this could be described, making it all the more so, by their incredible work together. Without the iTube2 present, this was a bit bright for my treble-sensitive ears; but when you infuse the tubular nature into the equation, well it simply sings. Adding not only depth, but also musical texture (warm by virtue of the tubes…) and body that are not present when just running the BL. And I am thankful for the addition. Over and over I listened, making out those subtle nuances of sound, of texture, of airy-accoustic guitar coupled with the solid bass guitar background. The sound is beautiful, and I have to say, that I played this song the most, followed by Guns For Hand and Look at Little Sister. I really wish Ziggy would receive the recognition he deserves. And as such, he did just receive the George & Ira Gershwin Lifetime Achievement Award, which is thoroughly deserved.


    Complimenting that is the studio version, and boy does it ever. From the opening native drumbeat to the acoustic guitar, and the support of the electric guitar, the song is superb through the iFi iTube2. Wrought with deep overtones of native beat, the tube sound adds to that rich display of sound. I feel as if we are in Jamaica as we listen. And I am happy. I play the song over and over, sometimes critically listening for the differences, sometime simply to listen. A deep sense of belonging is fashioned from this song, and it makes me quite honored to be included.

    A pattern has developed in my listening. One, which you could probably guess already. A sense of depth and rich texture pervade everything I play through the iTube2. As to how much depth and texture, well that depends upon the settings you desire. A full-on 12dB can be added through the bass boost, with a middle setting of 6dB (my preferred). If you desire a more open concert hall-like sound, then move the SET toggle to your desired spot, and enjoy.


    Additional hook ups:

    While perusing the offerings, I did hook the iTube2 up with my Shanling M1. Using the 3.5mm connector to the dual RCA connectors on the iTube2, then the BL, then headphones, I immediately noticed that the sound was not nearly as full and rich. While I could dial up the volume and settings, there was a definite lowering of quality…Not as rich, nor textured, nor detailed; I quickly reverted to the MacBook Pro set up. Order was restored. While I did not mind, and could adjust the settings to compensate (which is a benefit of such a system), the MacBook Pro was simply better. So I stayed with that. While a DAP would work (my FiiO x5iii was better than the M1), this really is made for desktop/laptop/home systems. As advertised, the iTube2 melds seamlessly with a home set up, and from the reviews I read, the 3D system benefits from that larger sound base. I do find that this system works well in the smaller situation, such as computers. So don’t rule this out for such situations. Versatile it is, adding that wonderfully velvet (almost an insult to use, probably better to use the professional term tubey-gooeyness) sound to pretty much everything I threw at it. Again, I do value a warm sound overall, but one that does not would be intelligent to give this critter a listen, too. If nothing else, for the way it enhances the sound, elevating it to a level above what it should. By that I mean the ability to make a recording sound simply sumptuous. What with this addition to the BL, the overall impression simply makes it for me, and I am glad.


    What with all of the tuning possibilities, from Buffer to Pre-amp, to the three each of 3D, Bass Boost and SET (tube settings); the number of possible listening scenarios is many. Throw in that you can fine-tune the Buffer/Pre-amp filters with 8 different dip-switches, and the possible iterations are quite numerous. One can surely find a sound, which they will find pleasing. In just a couple of hours I had the sound, which I enjoyed the most, tuning the unit until I was quite happy with the overall signature. Yes, it was on the warm side of neutral; but it was also the sound with which I liked the best. Even those who prefer a more cold analytical sound SHOULD be able to reach a listening level they will enjoy.


    I guess I am trying to say, that this little, and I consider it affordable, critter was easy to use (once Lawrance shoved me down the correct path!!), easy to change, easy to listen to, and easy to modify according to the needs of the song and signature desired. A “Jack-of-all-trades” would be an insult to this unit. The iTube2 is versatile, and worthy of an audition in not only your personal system but also computer and home system. It is quite good, and I was honored to be included on the appreciation tour. For that, I sincerely thank Lawrance, and @iFi for including me. This is a company, which gains my respect more and more with each passing opportunity to listen to their fine wares. Worth a listen, would be an understatement.

    Bansaku and B9Scrambler like this.
  4. ostewart
    "Tubey goodness just got better"
    Pros - Flexibility, sound quality, form factor.
    Firstly I would like to thank iFi for this sample to review, as always I try to write honest reviews, this unit has had over 50hrs of burn-in, no real differences were noted.
    Gear Used:
    HP Pavillion laptop > JDS Labs OL DAC > iTube2 > Marantz PM44 MKII SE > Denon SCM-50

    Tech Specs:
    You can find a comprehensive list on the iFi Website:
    Packaging, Accessories and Build Quality:
    The packaging is the same as the rest of the Micro line, which is fine by me. It comes in a long slim white box, on the front you get a picture of the product, on the L side of the box you get a true to size picture of the iTube2 side on, on the R side of the box it lists the key technologies used, and on the back you get the tech specs and additional information. One you remove the outer sleeve, and take the top off you are greeted by the iTube2 held in a little in tray. Underneath this you will find all the included accessories. They waste no space with the packaging, it is neat, looks good and I really like it.

    Included accessories are good, you get a pair of short RCA interconnects, a small flat head screwdriver for changing the DIP switches on the bottom, rubber feet, power supply and an adaptor for it so the plug that goes in the iTube2 is at a right angle for neater installation, you also get a quick start guide which is very good and explains all the features without going too in depth.
    Build quality is the same as the rest of the micro range, it is a slim aluminium housed device, all precisely put together with excellent finish. The volume knob is also the power switch, it operates very smoothly, the front switches all feel like they will last, the inputs/outputs are sturdy the only delicate part is the DIP switch panel on the bottom, but they will last if switched carefully, and most people won’t change them much anyway.

    This little device is packed full of great little features, I won’t go in to too much detail but I will try and list them all.
    For the most part this is a valve buffer/pre-amp that adds a little tube magic in to the sound of your system. The amount can change whether you have it set to a 0dB buffer/pre-amp or a 9dB gain buffer/pre-amp, the latter being slightly warmer.
    It has one pair of RCA inputs, one pair of outputs, the LED on the top starts off red when you first turn it on, and turns orange in aprox a minute meaning it is ready to be used.
    Now for the front switches:
    Closest to the volume knob you have the option to choose between SET, - or Push-Pull. This one is all down to personal preference, you can have it sounding like a Single-Ended Triode power amp, classic low-distortion tube-based studio equipment or a Push-Pull tube power amplifier. With my system I preferred the – position, it sounded the most up front and engaging.

    In the middle you have the Xbass switch, this is really good for smaller desktop speakers, iFi recommend the 6dB position for speakers missing only the lowes bass notes (40Hz and below), and the 12dB position for speakers missing some bass notes (80Hz and lower). Or you can leave it off if you have enough bass in your system. My little SCM-50 speakers benefited from the 12dB position.
    Last but not least you have the 3D Holographic with 30⁰+, - or +, iFi recommend the 30⁰+ for narrow placement of speakers, the – leaves this setting off, and the + recreates the original “width” of the soundstage and should be used as the default. I can say now this setting has completely changed my desktop listening experience, using the 30⁰+ due to my speakers being next to my PC monitor.

    Well this greatly varies depending on your system and settings, but once I had messed about with the settings a little I have it set up to my preference and it has completely changed my desktop listening. This device also works well as a tube buffer for headphone systems, where you want a little tube magic, just stick it between your source and amp and happy listening.
    Now I have this set up as a 0dB buffer, with the XBass set at 12dB and the 3D Holographic at 30⁰+, it has helped my speakers not sound as thin, and also the soundstage is so much more accurate. The tubes adds that little bit of warmth, that makes them sound less harsh but still very detailed. The Xbass really helped fill out the low end without any added bloat, it is very precise and well controlled.

    The 3D holographic setting though is a game changer, if I turn it off it almost sounds as if I am listening to a mono recording, the soundstage got so much wider, and more natural. Pinpointing instruments is so easy now.

    iFi Audio have taken the original iTube, which was and still is an awesome device, and managed to squeeze even more out of it without making it bigger, the great thing about this is that it fits in to any system and you can let it have very little influence over the sound, by having it as a pure 0dB buffer, and it will add a little tube sound. Or you can play with the settings and see what works best for your system.
    After playing about with the settings, it has made a big audible difference to my desktop setup which without this sounds a little thin, with very limited soundstage as it is not set up very well due to space and room constraints.
    Sound Perfection Rating: 10/10 (Such a great, featured packed device for all systems)
    Bansaku, Beolab and gr8soundz like this.