[SFDude]

Nope. It's both preamp and buffer in 'preamp' mode. If you used two you would have twice the price and double the redundancy which is rarely good. Now if you put one between your preamp and your source and another after your preamp and before your amp in buffer mode that would be excellent.

Wait what? I can use it between the preamp and amp? Ok. I thought the review was going to be straightforward (ie. between source and preamp) but looks like there are multiple ways you can leverage this and skin a cat. Making the review process a little bit more "involved" to evaluate. All within a week.

Time to pull up big boy pants and prepare to really work on this! 

-dave

[StevenZ]

Been dragging my feet a little here as I've had a busy schedule.  So here goes.

System:

Bluesound Node2
Luminous Audio Axiom Passive preamplifier with Walker Mods
Temple Audio Monoblock amplifiers (Just released version)
Cables are Canare interconnects and Belden speaker wire.
DIY Speakers built from Paul Carmody's Carrera kit/plan

So as you can see, nothing too crazy about my setup, but each piece was bought to work perfectly well with each other.  I love this setup, it's extremely honest, resolving and IMO is about as true to the recording as I've heard throughout my years dabbling in this hobby.  BUT, I wanted to see what all the buzz was about with the iTube2.  Perhaps, I thought, it would breath in a little life or something magical into my stereo that I wasn't aware it was missing.  So I signed up for the tour.

When the iTube2 arrived, I was able to hook it into my desktop rig at the office where i use a pair of Mark Audio Alpair 7.3-based speakers and a cheap Chinese integrated amplifier.  The amplifier is an Indeed Hifi TDA7498E.  This amp, for the cost, is pretty darn good but I always felt it was missing some staging, though I wasn't surprised by it's cost that it was deficient in this area.  Here the iTube2 really showed what it could do.  I used it as a buffer, buffer with gain, and as a preamplifier with the integrated's volume cranked to the max. 

As a buffer, and buffer with gain, I found that it did add some warmth to everything, and with the 3D setting engaged, I felt the staging the staging was pretty blown out.  I used the Bass feature at the office as I listen at very low levels, which helped to really get a better balance, similar to what a loudness button would do.  I also preferred greatly the SET function over Push-Pull as it seemed to suit my musical tastes a lot better, making things a little softer and more romantic.  I will be honest.  At first I felt the 3D setting and Xbass were a little strange as I'm the kinda guy who likes a "straight wire with gain" type of approach.  But the more I used these two settings, the more I came to respect their strengths in this type of setup. 

Still at the office, when using as a preamplifier, I thought it actually brought the setup up a few notches in terms of dynamic capabilities and better fleshed out the extremes both low and high than using it as a buffer in front of the integrated.  I noticed that the high end seemed to be crystal clear with excellent definition to drum kits and acoustic instruments.  The way it drove the music forward was pretty exciting and such a treat to have some actual life brought into the office rig, where most of my listening happens.

So, I took the iTube2 home with me and tried it again with all the settings and all the functions mentioned above.  I found that in my home setup the iTube2 did pretty well as a buffer and preamplifier.  Here at home I kept the Xbass off and same with the 3D setting.  Buffer was at 0db, same with the preamp setting.  At home I felt the Xbass wasn't needed as it tended to make my speakers sound a bit bottom heavy.  The 3D setting was interesting, however I felt when engaged I lost a little bit of precision regarding singer/instrument placement.  While it did sound cool on most recordings (MQA via Tidal) I found I preferred 3D off.  As a buffer,  it did seem to drive the signal quite well into the Luminous preamplifier, though with the additional gain setting I found it to limit my volume control usable range a little too much.  Bear in mind, even at home I listen at low levels as well.

When using as a preamplifier in my home rig I enjoyed the drive and pace that it seemed to carry with it.  It was fast, fun and ready to rock when called upon.  Here too I used the 0db setting with Xbass and 3D off.  I felt here, as with my office rig, that used as a preamp it allowed my speakers to extend higher and lower with great accuracy, especially regarding drum kits and acoustic instruments.  SET setting was what I preferred here too, perhaps because of my musical tastes again. 

I feel that if one's stereo needs what only tubes can provide, but doesn't want to plop for a megabuck preamplifier, this should be taken very seriously.  For me it does an admirable job at the office and can really bring up any desktop speakers beyond their normal ability to image in confined spaces.  I especially enjoyed the Xbass here which helped to fill out the sound even at low levels and I would definitely buy one if the funds permitted right now.

Cheers,
Steven

[genjamon]

Wait what? I can use it between the preamp and amp? Ok. I thought the review was going to be straightforward (ie. between source and preamp) but looks like there are multiple ways you can leverage this and skin a cat. Making the review process a little bit more "involved" to evaluate. All within a week.

Time to pull up big boy pants and prepare to really work on this! 

-dave

Yes, and not only that, but also settings for gain/no-gain.  I spent a couple hours last night trying to unravel what I was hearing in the no-gain buffer mode.  I hope I'll have a couple hours to play tonight with the gain-buffer mode.  Unfortunately, my weekend filled up nearly completely and I didn't have the time I had thought to really dig in for long sessions.  It'll be tough to sort out everything I want to try by end of week...

[Rusty Jefferson]

Would participants please add photos of their systems.  I'll be doing so, and I think it's insightful when reading comments about how something sounds. I thought Pez had requested this but I can't find a post stating it. Thanks.

[JLM]

Nice review Steven.  Yeah images would be nice, especially to get a feel of your listening space at home.

[GentleBender]

Have you looked under profiles to see users systems? Mine is under my profile, if it helps.

[Rusty Jefferson]

Have you looked under profiles to see users systems? Mine is under my profile, if it helps.

Thanks for that. Hadn't thought of it.  Maybe then, participants that don't have profile images?

[Phil A]

Would participants please add photos of their systems.  I'll be doing so, and I think it's insightful when reading comments about how something sounds. I thought Pez had requested this but I can't find a post stating it. Thanks.

I'm still breaking in mine.  I posted a pic of the office system speakers (Selah SA2s) in reply no. 23.

[mikeeastman]

I ordered one from here https://www.adorama.com/ifitubemicro.html?gclid=CJem57rQotICFZS6wAodVzcGMA, $40 less than B&H. It arrived on Mon. It will go  between my Mivera Purestream dac and my Ncore 400 amp. Unfortunately it arrived with one channel dead, have another on its’ way, should arrive on Fri.

[genjamon]

I ordered one from here https://www.adorama.com/ifitubemicro.html?gclid=CJem57rQotICFZS6wAodVzcGMA, $40 less than B&H. It arrived on Mon. It will go  between my Mivera Purestream dac and my Ncore 400 amp. Unfortunately it arrived with one channel dead, have another on its’ way, should arrive on Fri.

Just so you realize - that listing is the previous version 1 of the iTube.  The one we're reviewing here is the new iTube2.

[bacobits1]

I though that was a "1" the new one isn't going to be cheaper.

[mikeeastman]

Missed that, thanks.

[mikeeastman]

Ok right one on order. Thanks agin

[genjamon]

Sweet 

[jrebman]

I almost made that mistake with Amazon -- their search engine defaulted to the older version, not the latest. When I saw the mistake, I deleted that one and bought the correct one (and amazingly enough, it was the last one they had.)

Just be careful, it seems like there are some vendors out there who are attempting to clear out their older stock before they push the new one.

I did get the right one finally, and if all goes well tomorrow, I will install it in my main system.

-- Jim

[genjamon]

Ok, here goes.  Shipped the iTube2 off to Tommy2Tones this morning.  So, it's time for my review.  As reminder, here's my system:

microRendu > Lampizator Big7 w/volume control (R2R, but no superclocks - Takatsuki 300B's and Lampi Anni 5URG recti) > Line Magnetic 518ia (Psvane WE845 replicas, 1957 metal base 5AR4) used as straight amp bypassing its volume pot > Daedalus DA-RMa V2 speakers

Dual 15" subs driven by amp level inputs - placement and settings from REW/microphone trial and error

Entire digital source side including network switches/routers driven by either Uptone LPS-1's or HDPlex linear power supply with iFi DC iPurifiers.

Lampi and Line Magnetic power from a Zenwave SurgeX power conditioner with Furutech NCF outlets, and wall outlet is Furutech NCF as well - and all power cords are Zenwave PL11's with Furutech FI50 connectors

IC's used were Zenwave D4's, and speaker cables are Cable Research Labs Bronze

Music was mainly streaming from Tidal (though not with MQA engaged)







Basically, I've done everything I can to feed the Lampi and Line Magnetic with the cleanest low noise power and source signal I can, and each one of the cabling, power conditioning, and especially power supply upgrades to the network gear have upped the inner resolution, refinement, and also warmth/body of this system.

So, the iFi iTube2 went in between the Lampi and the Line Magnetic.  Lampi has an excellent integrated passive attenuator, and there are so many options with the iTube2, that I focused my listening on the buffer settings and not on use as a preamp - I just continued to use the Lampi volume control.

My first impressions were with the buffer setting at 0dB gain.  I listened to this for an evening, and honestly I felt there were positives and negatives to the sound.  The system without iTube2 had more warmth and organic engagement, and in some senses it had more overall musical information.  Yet, with the iTube2 in the system, the sounds of vocals were clearer and cleaner, and there also appeared to be greater soundstage depth and PRAT.  It was hard to decide which sound I liked better.

My second impressions were with the buffer at the 9dB gain setting.  I listened to this setup for several sessions of 1.5-2 hours.  This was a different story. Without swapping back and forth, it was a very engaging sound.  I would mainly listen for a while with the iTube2 in the system, and then toward the end of the listening session, I would remove the iTube2 after listening to a well-known song or passage, and then replay that song/passage without the iTube2, and then re-insert the iTube2 and listen to the same song/passage again.  I might do this 3-4 times with different songs/passages in the last 30-40 minutes of a listening session.

Basically, I found the iTube2 to have a cleaner and also more relaxed sound, with a slightly less dense portrayal of instrumental body/warmth, but with overall better clarity and finesse.  I thought my system was already very clean and refined and resolving.  But I'll be damned if the iTube2 as a buffer with gain didn't increase overall refinement.  Voices lost a bit of stridency, sibilance was reduced, reverb and ambience had even more extended decay and detail, complex passages had even more instrumental separation and placement - just all around more resolved and refined sound. 

I did prefer the iTube2 with the SET setting more than the standard or Push/Pull setting for the tube in this system.  And it was a tremendous help to have these options to play with to find the right fit for the system.

So, I've placed my order for my own iTube2.  And it has convinced me that a preamp is definitely needed in my system.  Maybe the iTube2 will retain its place of privilege in the main rig, but I'll also be interested in checking out some 6sn7 based preamps like the Don Sachs or the Linear Tube Audio stuff based on Dave Berning's work to compare with it.  If any of them are a better fit in the system than the iTube2, I can always make use of it in my TV system.

Which brings me to the TV system.  I also tried the iTube2 for a night in that system - which is just a simple Schiit Modi2 DAC, older Acurus preamp, and Miniwatt S1 amp, powering Tekton Lores that have rebuild crossovers with upgrade caps/resistors and wiring.  I didn't do any careful comparisons in this system, but the iTube2 was a cleaner and clearer preamp than the Acurus. 

So, that's my review!  Hope it's informative for some of you.  And in the end, I concur with Tyson that the iTube2 is no joke, and can easily find a place in a very high performing system, despite its relatively modest cost.  And I do wonder what it would sound like if powered by a 12V Vinnie Rossi outboard supercapacitor power supply...which is what I may try if one of these 6sn7 preamps doesn't unseat it.

[JakeJ]

Hi folks,

Can anyone tell me what the spacing (center to center) of the RCA jacks are?  I'm curious if there is room to use balanced to RCA adapters.

TIA,
JakeJ

[charmerci]

Wow! That's an amazing system you have there! 


Good to hear that the iT2 helps even yours. I'm still over 2 weeks away from getting it - and the time seems to go sssoooo s-l-o-w-l-y....

[Phil A]

Hi folks,

Can anyone tell me what the spacing (center to center) of the RCA jacks are?  I'm curious if there is room to use balanced to RCA adapters.

TIA,
JakeJ

It's about 5/8 of an inch.

[JakeJ]

Thanks, Phil!

So I took a pair of adapters I have laying around and set them side by side on the desktop and measured the RCA center pin distance and it is 3/4".  This would put too much strain on the jacks and adapters so I will be using only RCA cables when the tour unit comes around.

JakeJ