REVIEW : Jaben's GoVibe Porta Tube Amp - Review Thread (ex demo)
Aug 18, 2011 at 7:03 AM Thread Starter Post #1 of 62
Jan 30, 2011
Thought I'd kick this off and ask anyone who's involved in the demo circulation to post their impressions.
Aug 18, 2011 at 7:04 AM Post #2 of 62
Porta Tube (GoVibe) - Something Really Special.

Firstly - I don't have a lot of gear, so when I got the opportunity to try this I was really grateful.  Many thanks to Josh and the team at Jaben for making this happen.  I've never experienced a tube amp before - and unlike a lot of the other demo-ers, all I can do is compare this to my E11 (portable) and E9 (desktop) setup.


To make it nice and fair - for all three amps I am using the same source (iPod Touch G4 via LOD).  I'm comparing using a set of DT880 Pros (250 ohm), and I'll also briefly comment on my Alessandro MS1i & Brainwavz B2.

Physical Dimensions
The Porta Tube measures approx 115mm x 73mm x 28mm.  Add another 13mm for the volume pot.  It weighs approx 315g.  Comparatively my E11 is a fairly diminutive 92 x 54 x13mm and 65g.
The Porta Tube has a 3.5 mm input socket, and dual 3.5mm and 6.3mm headphone out sockets.  It also has a power on/off switch, and an adjustable volume pot.  It operates off an internal rechargable battery which Josh tells me is good for around 10 hours portable use.  It is recharged via the included wall-wart.  You can power the Porta Tube off the mains, and listen at the same time - so it would be good for desktop use.  It also comes with 4 small rubber footings prefitted - again good for use in a desktop setting.  The top is vented, and you can just catch a glimpse of the tube when in operation.  The Porta Tube does generate a bit of heat when operating - but nothing excessive.  It's warm to the touch - but definitely not hot.


It came with a plug, an adaptor, cord for connection to a suitable DAP, and a nice velour case.


Technical Specs
I hope to add to this section - if I can actually find any information.  Unfortunately nothing was included with the demo box, and I cannot find a website.  I have asked Josh for more information, and will edit this post if I discover anything.
First impressions
Aesthetically the unit is really quite sleek, and looks extremely well built.  The pot is a little loose, but apart from the little bit of slack, it has an extremely nice smooth motion.  Whilst I couldn't see myself using the GVPT in a really portable situation (ie on the move), I could see myself taking it with me to work, or to a cafe, or anywhwere else I just wanted to chill out.  It looks fantastic on a desktop - sleek and unobtrusive.
Once I charged it, I connected my headphones, and had my first listen.  First impression, and hasn't changed after the 10 hours or so I've been using it - very clear, very balanced - warm and eneveloping - and very smooth.  This has been my first listen to a tube based amp, and I really like it.  With the 250 ohm DT880's, I'm only at about 1/4 on the volume pot - so this little amp looks to have a serious amount of driving power.  I asked my wife (she has the better ears) to listen with no music playing, then raised the volume to 100%.  She confirms what I hear - or more precisely didn't hear.  Even at maximum volume, the amp is completely 'black' - no hiss, no noise.
To give you an idea of how good this unit is (to my inexperienced ears), I recieved it on Tuesday, and fully intended to run it through it's paces, and get started on comparisons.  From first listen - instead of critically trying different genre's and testing strengths and weaknesses, I ended up 'lost' in Eric Clapton's "Unplugged" ablbum, and from there to Nils Lofgren's "Acoustic Live".  Over two hours elapsed, and I was just sitting there with a silly grin on my face - totally enjoying the music.  Almost three days later I'm finally sitting down to put together some impressions - then I can get back to simply listening again.
(Photo - you can just see the tube through the grill)

Sound Quality & Comparisons
Having never heard a tube amp before, I didn't know what to expect.  I'm not very good at describing in audiophile terms - so I'll simply tell you what I'm hearing.
  1. First, it appears really detailed - I am hearing everything, and it is really clear.
  2. I'm also finding that instruments are well separated - I am able to listen to everything, and that's what makes it so engaging I think
  3. Mid-range (especially vocals and acoustic instruments) are really smooth and an absolute pleasure to listen to.
  4. Bass has a nice kick and is quite punchy. No sign of boominess or hollowness.
  5. Highs are not overly prominent - maybe rolled off a little, but this still has sparkle for me - so it's a really nice overall tone.
  6. If I had to sum up in a few words I'd say smooth, warm, rich but sweet - definitely not dark.
OK - onto comparisons:
Classical - Julia Fischer and the Russian Philharmonic (Tchaikovsky's Concerto for violin in D, Op. 35: I. Allegro moderato)
GVPT - warm and enveloping - the timbre of the violin sounds really perfect
E11 - overall warmth is still very good - just lacking the clarity and sweetness I was getting from the GVPT.  For the first time to me the E11 sounds a little 'dark' in comparison.
E9 - closer to the GVPT overall - but again doesn't sound quite as sweet.  Clarity is good though.  Still very enjoyable.
Jazz - Diana Krall (Love Me Like A Man)
With all three amps, this track was actually quite closely matched.  The main difference was a little more sparkle with the GVPT, and also a shade more clarity.  But all 3 (because of their warmth) make Jazz shine.  No clear standout winner here - all very enjoyable.
Blues - Joe Bonamassa (Another Kinda Love - live)
Bass line is good with all three amps.  All 3 are very similar once again - with the E11 and E9 being slightly drier in the vocals.  The main difference with the GVPT is a sense of smoothness and richness.
Classic Rock - Eric Clapton (Layla)
This one was easier to spot - all three sound great, but the GVPT has the edge with clarity, and just sounds more engaging.  It somehow just pulls me in.
All 3 amps are really close.  There is no doubt that the E9 and GVPT have the edge with pure power.  Overall difference is mainly clarity (minor difference in favour of the GVPT) but also sweetness,a nd richness of tone.  Especially with acoustics - I find myself lost a little more with the GVPT.  It's hard to describe - perhaps best to say that the GVPT just provides a little more 'body' and 'timbre'.  It's also quite lifelike.

Other Headphones.
Sadly I recently sold off my SRH840's, SE425's and AD700's - to make way for the DT880's and SRH940's.  Unfortunatelly the 940's are in transit - so all I have left is the Brainwavz B2 IEM's and my Alessandro MS1is'
The B2's are extremely easy to drive - and to be honest, the GVPT really supplies too much power.  I had to have the volume down so low that I was in danger of channel imbalance on the pot.  When I got it right, it makes the B2's really sweet.  Takes a little edge off the highs - which is nice, while still retaining a great mid-range.  If the GVBT had a gain switch - it would be easier.
MS1is - I have a couple of mods done with these already - quarter modded Senn pads & vented 4 joles to add a little more bass impact.  They're still pretty bright compared to my Beyers.  The GVPT really goes well with the MS1i's though.  The brightness is still there, but it's somehow more palatable, and very engaging.  I'd love to hear these again with the GVPT - after I eventually woody them.  In the meantime a really good match - especially for rock and blues.
Summing Up
Based on the sound and form factor - I've really enjoyed this little amp, and if I had the money, I'd definitely consider it.  What it has done is kindled my interest in a tube based amp.  The GVPT does everything right for my ears - very musical, sweet and engaging.  I'm pretty sure it has a really good synergy with both the Alessandros and also the Beyers - but especially the Beyers.
I'd like to close in saying thanks to Josh for this opportunity, and for giving the community a chance to participate and enjoy it.
Aug 18, 2011 at 8:03 AM Post #3 of 62
Nice review mate.

I agree with the ms1s being a good match. I'll post some more impressions later on.

The only downside is the cramped soundstage. But still it's a great amp.
Aug 18, 2011 at 9:59 AM Post #4 of 62
Thanks for starting the thread up, it's a solid start. I'll post my impressions when I have time to give it a more thorough review.
Aug 20, 2011 at 3:00 AM Post #5 of 62
I'll have less pics since Brooko has already done a great job with showing it off. 

This is my first tube amp, and my first real review, so bear with me.

iPod Nano -> FIIO LOD ->GVPT (the headphones connected is a pair of HD25-1 IIs)

Here is a picture with all the items I got as part of the package (also pictured is my Nuforce Icon HDP). I've already attached the rubber feet to the GVPT. I was lucky enough to have a pair of IEMs to audition as well (Feels Pro900). I'll describe my impressions later.

Technical Specs

I couldn't find any online, so I'm leaving this section blank for now.

First of all, thanks to Josh and the Jaben team for giving me the opportunity to test the GoVibe Porta Tube Amp. I've only used solid state amps before, so this is new to me. Thanks a lot!
Now, on to the review!
First Impressions

At a first glance, the unit is fairly sleek and well-built. Its design is simple and to-the-point, nothing too confusing for a user of any level.
In regards to portability, it's clearly not as portable as an E11 and the like, but is portable enough for me to take to work or any other location I'd be sedentary for a while.
In regards to initial sound quality impressions, it's a great little amp. It's certainly increased the clarity of my music connected from my iPod. It's a joy to listen to and I find myself lost in the music at times.
In regards to "hiss", I certainly hear a hiss with the 32 ohm Feels Pro 900 IEM and my 70 ohm HD25-1 IIs (particularly at the highest volume). I don't hear any hiss with the HD 650s (300 ohms).
In regards to the temperature of the amp itself, it does not go above warm, in spite of hours of usage. It's built well.
More detailed analysis
I'm fairly new to the audiophile world, so I'll describe it the best as I can. As a further caveat, I'm unsure how good the GVPT is with my Sennheiser headphones in terms of synergy.
In regards to my setup, I'm using iPod to GVPT with a FIIO LOD (highest quality v0 or 320kbps mp3s) as well as hooking up the pre-amp of my HDP to output to the GVPT, keeping the knob at 3 o'clock while the HDP is standing vertically (trying to avoid clipping) with FLAC sources.
Amp Power
  1. Certainly not lacking power by any means. It drives my HD650s and retains a solid amount of clarity.
Amp Sound Quality/Signature
  1. As tamu mentioned, the soundstage somewhat cramped, but is still much better than it would be otherwise.
  2. Instrument separation and vocals are solid (as Brooko mentioned, the mid-range really shines).
  3. Instruments and voices are natural-sounding.
  4. Bass has quite a bit of punch, yet does not sound unnatural.
  5. Highs are a tad rolled off (I really heard it in Scene 1. Moderato of Swan Lake in the crux of the song).
  6. As for a general sound description, as Brooko said, it's warm, rich, and sweet. Not harsh or dark by any means.
Other headphones
HD 25-1 II
Easily driven by the GVPT. I keep the volume control around 9-12 o'clock and only push it higher for songs recorded at lower volumes. It works great with it and is quite a potent portable setup. I love listening it when hooked up to my iPod nano. I find I find the most enjoyable songs are rock and folk songs. The instrument separation and the fullness of the sound make it a pleasurable listening experience.
Feels Pro 900
Driven  with ridiculous ease by the GVPT. I have to keep the volume control around 9 o'clock or it becomes unbearably loud. As mentioned before, there is noticeable hissing during dead periods. Sounds decent with the GVPT, but as a caveat, I'm not really an IEM person. It shines with relatively bass-heavy songs (some songs from Daft Punk, etc.). Those are a blast to listen t .
Also, since I got this as part of the loaner program, I'll give this a quick review.
I'm not much of an IEM person (I prefer larger headphones), but this is a solid set. As previously mentioned, the bass is great, but the mid-range is also pretty solid. The highs and soundstage are decent.  I just prefer larger headphones, but at around $60, they're a great set for the price if you're in the market for IEMs. Certainly better than skullcandy and stock Apple earbuds.
I've enjoyed my first taste of a tube amp. It's a great for a portable setup, particularly in a working environment. Thanks once again to Josh and Jaben for letting me try it. I hope the next person enjoys it as much as I do.
Aug 20, 2011 at 5:56 AM Post #6 of 62
Thanks for the impressions.  Interesting on the hiss - I'll have to try it with some other gear to see if I get anything similar.  Mine does appear to be quite "black" (soundless) so far - with both the Beyers and Alessandros.  It's a great match with the MS1i's - been listening to them for a lot of today.  Just ended up confirming a purchase with Josh - shows you how much I really like this amp!
Aug 20, 2011 at 11:48 AM Post #7 of 62
I have a few more pictures in this thread:
I would love to spend more time with this amplifier. I was very impressed when I heard it at Jabens in Hong Kong. I wish there was a loaner program or something. 
Also I think the price was a bit high to in order to make a decision to buy it immediately. 

I just had a chance to listen to the GoVibe Porta Tube at Jaben in Hong Kong and I was deeply surprised by its sound. I paired it with my own travel companions my iPhone 4 with ALAC and DT-1350 and a pair of HD650 present in the showroom and specially with the DT-1350 it was a great combination. I only had 15-20 minutes in the shop as I was on my way to the airport but that was enough to put this amplifier on my list. This amplifier is the most rich and lifelike portable amplifier I have heard with great detail and a warm-ish sound to it.
I could not find a lot of info about it here. That is probably because it was released for sale less than two weeks ago but if anyone has done some comparisons to other portable amplifiers I would love to read more about this. It is not the smallest portable amp but fully worth the extra size. 
Here are some pictures.




Aug 24, 2011 at 6:15 PM Post #8 of 62
Just received the loaner.  First impressions.....Positive!  Seems to be doing quite well w/ the HD800 out of the box.  Need to flesh out the pairing more then will try my T50rps and some IEMs.  In case I missed it what was the rated output impedance again from 6.3mm and 3.5mm?
Aug 25, 2011 at 10:27 AM Post #9 of 62

Just received the loaner.  First impressions.....Positive!  Seems to be doing quite well w/ the HD800 out of the box.  Need to flesh out the pairing more then will try my T50rps and some IEMs.  In case I missed it what was the rated output impedance again from 6.3mm and 3.5mm?

If I may ask - is there a loaner? Is it only a US loaner program?
Looking forward to hear more Anaxilus....
Aug 28, 2011 at 2:09 AM Post #10 of 62
I got this amp for loan last week, and here's my impression about it.
The amp comes with
 - feels iem
 - 3,5 to 3,5mm jack
 - rca to mini jack
 - ipod LO dock
 - Wall Charger
Here's my unit side by side with ALO continetnal

Physical Impression :
Build quality seems great, it handles well; i prefer this over ALO continental physically. a bit big and bulky compared to most portable amp. I'm not sure with what tube is used but it looks a bit bigger than the 6111 tube and i didn't open the unit as this is just a loan. The tube won't get hot and it just warm. As for portability, you can't use this for daily use as in if you ride bus to work; sometimes you hear the tubes moving if you walk. It got 3.5mm and 6.3mm output jack; however the 6.3mm jack in my unit is a bit loose and sometimes you lost the sound in the right channel. Battery live is arround 7 hours which is pretty good compared to continental.
For driving capabilities; they claim that it can make akg k1000 sing, when i tried this on k1000. Yes it does sound but doesn't bring the full potential of it. To reach the listenable level, you need to crack it up to almost max (arround 3 or 4 o clock). It drives everything else with no problem though.
Sound impression :
Song used :
Hotel California - The Eagles (live) - Hell Freezes Over - WAV
Source : Ipod touch 5g, sansa fuze
headphones used : AKG k701, AT esw10jpn, AT w10ltd,
This song is the one that i really remember, i listened to this song over and over again in many phones,
One thing that you may notice directly is this amp perform really well on midrange and high notes, the guitar string sounds so crisp, it sounds so realistic to me, feels like I'm listening to a real guitar and the tubes kicks in just in time when needed, it sounds great. vocal is lush and smooth, a bit congested for don's voice but still tolerable, bass is punchy but for me not really well defined, i've heard better from portables amp and in this one is just fine, i can't feel the bottom-end of the conga and is just of mid-bass. Soundstage is a let down. I feel the soundstage is very cramped by width and depth.
Separation is great on my w10ltd and just fine on my esw10jpn. I feel the sound is a bit too bright on my esw10jpn. It is a bit tiring and fatiguing on those.
Oh, i tried this amp with Senns HD600 and for me it pair wells (compared to my Audio Technica), mostly due to hd600 open design (huge soundstage) and laid back sound which balance each other very well.
Overall, i pretty much like the amp, I'm not sure about the price but if it is 600us$, I think that's a bit too high for portable amp,
Aug 28, 2011 at 6:02 AM Post #12 of 62

Well, how does it compare to the continental?!  I thought that was going to the whole point of the post, lol.

Me too 
normal_smile .gif

Aug 29, 2011 at 7:25 PM Post #13 of 62

I got this loan side by side with my continental (which i sold within 10 days). unfortunately my continental didn't pair well with any of my headphones and they are not fully burned, can't use them with any HD218/228/238 (they screech !!!! literary screech i dunno what happen ... sorry i'm a newbie) then went to meet and tried it with a pair of k701 but meh still doesn't work well, didn't tried continental with k1000 don't think it powers them, but somehow it works with my k430,
here's comparison between them in akg k430 :
my source is pico dac, ipod 5th gen, sansa fuze
1. soundstage of continental is substantially bigger than portatube,
2. I prefer the highs on porta tube, somehow i feel continental is too bright, porta tube's high is just sweet with a bit roll off especially on my esw10jpn which makes them sounds ..... more beautiful (i dunno the right word, sorry !)
3. porta-tube sounds more detailed than the continental
4. Separation in both are fine with continental in lead
5. midrange in continental sounds a bit more forward
6. Bass in porta tube is a bit lacking, but continental bass isn't that great either, i feel that continental's bass mostly is just mid-bass hump with least amount of deep bass and they sounds a bit boomy.
That's my impression so far, keep in mind that this is just my opinion and this is tested with a cheap headphones and is not fully burned in so if you try it with better phones the result may be different.
Anyway, they sucks with my Audio Technica, esw10 and w10ltd, it just sounds worst on them.
Well, it's true that they aren't made for them anyway...
Oh, porta tube dissipate heat better than Continental, and they are not prone to fingerprint unlike continental. and i feel them a bit lighter than continental. Battery life is about the same, connectivity porta tube has 6.3mm jacks so they are more convenient,
pictures :

Just my 2 cents.

Sep 30, 2011 at 9:16 AM Post #14 of 62
Two questions regarding the Porta Tube.

1. Has anyone seen anything indicating whether it benefits from any 'burn in' period and, if so, what was the recommended 'burn in' time?

2. For those that have experienced it, can you make a comment on whether, like some full size tube amps, it appears to improve in SQ after a warm up period?

Looking forward to any genuine replies (Please don't turn this into a diversion about whether 'burn in' or 'warm up' are valid concepts or the like. I'm just interested to see if anyone has experiences with/opinions on the Porta Tube in these areas).

Oct 1, 2011 at 4:17 AM Post #15 of 62
I was in Jaben today, and another gentleman was trying out the Portatube while I was comparing the Rx Mk2 to my E11. We got to talking after I heard him mention the Continental - one of which I have arriving from ALO in the next few days. After he finished his testing, he passed it over. I listened for a few moments to the intro of Marilyn Manson's "The Beautiful People" and the difference between the Mk2 and the Portatube was night and day. More ... "raw" is the only way I can describe it. It was one of those moments where you push something away that's too expensive lest you become addicted. A great portable amp... Hope someone more knowledgeable reviews it against the Continental.

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