iFi-audio Micro Series – iTube/Pre-amplifier Review: Part I

iTube buffer only (zero gain), DAP and 3D Holographic settings off

I began the audition listening solely with the OppO 981 and the Virtue M451 Sensation (class T) integrated amplifier, after which I inserted the iTube between the OppO and Virtue, and listened to the same tracks again. I then reversed the process and listened once more (A-B-A method). This method was used each time for subsequent changes in setting.

Initially I used the iTube strictly as a buffer without the preamp and all other features turned off, with zero gain. Even with the preamp bypassed, one still has to turn on the unit with the volume control to operate the iTube. Overall, the major sound difference between no tube buffer and with tube buffer is a slight increase in midrange warmth and slight increase in instrumental color. The general sonic character did not perceptibly change with buffer inserted. Both the treble and bass regions are not adversely affected, which is good news for solid state fans. Vocals have slightly more “presence” with a smoother presentation, and instruments have better “sparkle” with improved harmonics making them sound more like real instruments.

On close-microphone recordings, the iTube does not eliminate nor increase sibilance. Unlike some components which emphasize or de-emphasize the frequency range where male and female vocals reside, the iTube does not add or subtract but merely presents what’s on the recording. This is evident on the track “I Can See Clearly Now” from Holly Cole’s Don’t Smoke In Bed, where the iTube produces the “s” sounds more smoothly and naturally, without added emphasis or de-emphasis.

Ian Axel’s voice has a sandy grit on “Say Something” from his album This Is the New Year when heard through the OppO alone. His vocals became less gritty and more solid with the tube buffer. The harmonic overtones of Axel’s piano also improved, showing that it is very much a percussive instrument.

With a more complex musical structure, such as the song “Set Things Aright” sung by Daniel Martin Moore on the spiritually inspired album, In the Cool of the Day, the accompanying guitar, banjo, mandolin, violin, piano, upright bass, and drums all have more distinctive harmonics to distinguish them as being quite different instruments with the buffer in place.

In all these songs and others that I did not include in this review, I strongly preferred the tube buffer in the chain at all times.

iTube buffer only (zero gain), DAP on, 3D Holographic off

Same setup but with DAP on, the general change in sound was a further increase in midrange warmth, especially vocals, providing a more “lifelike” performance.

On the Holly Cole track, there is a high degree of crispness in the fingering and plucking of the upright bass with DAP off, but a slightly more rounded and less defined quality with DAP engaged. On the other hand, with DAP engaged, I can hear deeper into the recording–there’s more reverb on Holly Cole’s singing–thus creating an illusion of more air around her voice.

With DAP on, there is further lessening of grit on Axel’s voice, while there are more harmonic undertones and overtones present making his piano sounding like a fuller instrument. This track benefitted in all ways with the DAP engaged.

The tone of Daniel Martin Moore’s voice is spot on with DAP, much like I heard him in concert recently; however, there was a slight blending of harmonics with the banjo and mandolin making them sound more like similar instruments than without DAP.

So the final result is a mixed bag, since I prefer some differences and others not as much with the DAP on. Each listener will have to judge which qualities he or she likes better.

iTube buffer only (6 dB gain) DAP off and on, 3D Holographic off

Other than an increase in volume with the additional 6 dB gain, I didn’t detect any changes in tonality or harmonics, or a change in resolution, which is what I expected to find. I suppose the extra gain would be useful for mobile sources like a smart-phone or iPod, which has a much lower than standard 2 volt line level output of the typical CD player.

3D Holographic narrow and normal settings on

With the 3D feature set for listening with normal speaker placement (switch in down position), I heard a slight widening of the sound stage with bass notes on a few tracks, but on most song selections I could not make out any spatial movement changes. My AAD speakers are usually spaced a little more than seven feet apart, so perhaps more narrowly placed speakers would benefit better with this setting.

Since I don’t have a desktop system but do own Audio Engine A2 powered speakers, I decided to assemble a temporary system on top of one of my desks, placing the AE A2 speakers about two feet apart. I heard an expanded soundstage with the narrow 3D setting engaged on all recordings.

Besides a change in the soundstage, instrumental tones sounded flat when heard without the 3D effect on, with the track “Set Things Aright.” With the narrow 3D setting engaged, each instrument sounded fuller and richer.

The same improvement in tonality and spatial expansion were heard to great effect in Antonin Dvorak’s Symphony No.9 in E minor “From the New World,” conducted by Istvan Kertesz and performed by The London Symphony Orchestra. The individual sections, as well as the entire orchestra, sounded more vibrant and alive, while the soundstage widened considerably.

With the iTube’s numerous optional settings, each listener can fine tune and tailor the sound to his/her taste.

Preamp and buffer on

Using both the preamp and buffer does not sound good. No, the combination sounds shockingly good! Does the sound quality approach the best (read expensive) preamplifiers I’ve heard? Don’t be silly. What the iTube provides is a tantalizingly large amount of superior sound of which the best preamplifiers offer in spades, yet only costing a fraction in order to achieve it. On Dvorak’s Symphony No. 9 and Daniel Martin Moore’s “Set Things Aright,” both recordings sounded very open, immediate and transparent, only lacking the last degree of refined ease and resolution which makes me think I was listening to the actual performances rather than reproductions of those performances; an ability offered by my reference Rogue 99 Super Magnum preamplifier. Oh, and the iTube only has one set of RCA inputs, making it a single source preamp. What do you want, the moon? Well, you can’t get it for $299. I suspect if the 20- and 30-something generation of music lovers get to hear this component and other iFi-audio devices, a significant number of them will become new audiophiles in some sense, thus making older audiophiles more comfortable in the belief that the hobby will “live long and prosper.” You didn’t know Spock is an audiophile?