# JUST AUDIO - uHA-120 headphone amp



## RobinHiFi

Don’t know if this has appeared already?
   
  I took part in some of the testing for the uHA-120, there were 3 different units with differences in the components in that test so I cannot give a full description of the sound of the final design. I have a good idea which unit most closely represented the final design as I got to speak with Justin who is the designer and gives the first part of his name to the brand.
   






   
  Justin clearly knows his stuff and has big plans involving DACs and balanced designs, his enthusiasm for getting the very best out of these units is infectious – I have an iBasso D10 which I love but I have to say that the amp stage in theuHA-120 blew it away. The sound in general was powerful with a true feeling of accuracy, very detailed without oppressive at the top and deep smooth bass. I used Grado SR325is, Shure SRH840 and Ultrasone HFi780 worked well for all three.
   
  The uHA-120 had a compelling sound but was also beautifully built feeling really solid with a reassuring weight which felt just right for the size, the casing and its printing has been really nicely finished.
   
  Just Audios other amp is the AHA-120, a pure class A variant of the uHA-120 and they will also be offering some studio quality custom interconnects.
   









   

   
   
  Website is http://www.justaudio.co.uk


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## RobinHiFi

[size=medium]The uHA-120 offers possibly the best  solution to exceptionally high quality headphone amplification, which will also fit in your pocket. Ideal for the discerning audio enthusiast or professional, requiring bigger box performance in a smaller more convenient high quality product.​[/size]

 [size=medium] Unlike many similar products in the marketplace, we decided to use a discrete output stage, enabling us to fine tune the circuitry to provide the best possible performance from the design choices made. To confirm the best sounding configuration, we involved an independent  panel of enthusiasts - with combined exposure to most of the products sold in the UK market - to blind test several pre-production units (each of course with a slightly different configuration).[/size]

 [size=medium] The amplifier includes the option to upgrade the standard high quality stereo potentiometer (used to adjust the volume) and rotary power switch, to a custom made Vishay P11, which we fit as standard to our class A variant (the AHA-120).[/size]

 [size=medium]  [/size]





   
   




   
 [size=medium]Specification​[/size]

 [size=medium] Maximum Continuous Power output:[/size]

 [size=medium] 60 mWrms/channel into 32 ohm @ nominal (3.6V) battery voltage;[/size]
 [size=medium] 10 mWrms/channel into 300 ohm load @ nominal battery voltage;[/size]
 [size=medium] 16 mWrms/channel into 300 ohm load @ fully charged (4.2V) battery voltage;[/size]
 [size=medium] 28 mWrms/channel into 300 ohm load with 5.2V USB power supply;[/size]

 [size=medium] Distortion (THD): <0.005% @ 1KHz (-20dBu to 5dBu output level)*;[/size]

 [size=medium] Dynamic range (dBA): >100dB[/size]

 [size=medium] Bandwidth (-1dB): 10Hz-40kHz[/size]

 [size=medium] Output impedance: < 7 ohm[/size]

 [size=medium] Output current limit: +/-80mA per channel[/size]

 [size=medium] Maximum Gain: 12dB;[/size]

 [size=medium] Battery recharge time (max): 2.5 hour fast charge; 6 hour normal charge;[/size]

 [size=medium] Dimensions (approx): height=23mm; width=52mm; length=85mm[/size]

 [size=medium] Weight = 125g +/-1g[/size]

 [size=medium] * Both channels driven with 32 ohm headphones connected.[/size]


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## b0wl1ng

I am very pleased with my recently purchased amp, a very well manufactured and robust pocket sized portable amp, (exact size and depth of a packet of 20 cigarettes), I have been interested in an audiophile quality small portable amp for quite a while.
   
  As soon as I switched it on and the low warm thump of the vishay volume pot kicked in I was keen to play some music with it, my source and my primary use is a 4th generation 80gb iPod classic LOD line out and Apple lossless format.
   
  I was most keen to be able to use a portable amp that would be able to drive my low impedence Denon AH-D5000 cans that I adore, I did speak to Justin the designer and owner at Just Audio, he was extremely helpful and most informatve and extremely enthusiastic , as it should be with a newly developed product.
   
  I was very impressed with this amp, the sound quality matched with the Denons was warm and luxurious, superb detail and every nuance there to hear, the highs were crystal clear, the mids warm and liquid and the bass most excellent.
   
  I have also listened with my Grado 325i cans and the sound quality is also exceptional, I would consider myself an audiophile from way back to the 70s and more high end gear has come and gone over the years than you could shake a stick at.
   
  This gorgeous little amp ticks all the boxes for me, a true pocket sized audiophile quality amp, just perfect whilst cooking and on the move, a very, very, impressive product and a snip at the cost.


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## cn11

I was approached by Justin at the UK meet Saturday to give some of the IEMs a run through his new amp. He sort of walked over a bit sheepishly, bespectacled, and asked if I'd be willing to try out a new amp with some of the IEMs at the table, and then slinked away (I suppose he knew how good his amp is, and didn't have to wait around to see my reaction). Well I was in the middle of chatting with a couple of the other HF'ers who until Saturday were only screen names to me. And at the same time I was finishing up listening to a pair of RE272s straight out of my Sony X, while unknowingly having this gem of an amp just sitting in front of me waiting to be listened to. I started off with the RE272s, and thought, hmmmm.... this is rather bright. I then decided to try it with my Sony EX1000s so I was using a familiar phone, and when I pressed play I was amazed at the scale of sound I heard. The notable things right away were the bass, soundstage/air/headroom, and tactile treble quality. Very nice stuff. I decided to plug in my Arrow 3G for comparison, and immediately it sounded like the stage size had collapsed. And I noticed the bass sounding thin (no bass boost activated), with not as much treble extension either. I finished up that song with the Arrow, and went on part way into the next and then paused to quickly swap back to the uHA-120. And yes, there it was again, that huge scale. It's a ballsy amp for sure. I had never heard that level of bass, flat, on any portable amp. This includes the RSA Mustang and Shadow, ALO Rx, and the mentioned Arrow. The bass is even more deep and extended than my Lisa III w/power module (bass knob flat). 
   
  Once back in the States at work, I've been listening while cranking away on projects, paired with my Pro 900s. Talk about a huge, detailed sound, with stunning bass. Wow. Now this is system synergy. Really, really large sound, with the most crystalline treble, and wonderfully expansive mids. The only way it's lacking in comparison to the Lisa III rig is in soundstage size, and perhaps a little air. The bass is superior, and I think possibly even that crystal-like treble quality. I'm hard pressed to choose between the two for sound quality.
   
  Kudos to Justin for designing such a superb sounding portable amp. It's a long-term keeper no question.


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## Kunlun

So, about $322.
   
  It's comparible in price to the arrow and ttvj slim, larger in height but it seems much better sound than the arrow.
   
  Huh.


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## cn11

Yes, a bit chunkier, but pretty similar to the size of the RSA Mustang from my recollection. It's only 1" thick at the black bands, and about 7/8" at the case.
   
  The sound is definitely a noticeable jump over the Arrow. It's at the same level as the much bigger Lisa III rig. I really wasn't expecting such a nice sound from the amp when Justin handed it to me. Had to have it.


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## b0wl1ng

It is a very good amp, I have one of the first ones produced, number 004 , where this amp really scores is in its detail, very precise and accurate,plus the built in Lithium battery is a real plus factor.


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## Somnambulist

It was fun seeing your reaction. It certainly did sound great with my stuff too and while I was dead-set on wanting an Arrow after hearing it slightly earlier in the meet, it's given me food for thought! It did sound larger, livelier, and as you've said elsewhere, the bass response felt like the Arrow 3G with the bass boost on +1. The only thing going against it for me would be the form-factor, as I think things like the TTVJ Slim and Arrow match the dimensions of most modern players better and make for an easier to pocket experience. That said, it's still not _that_ big.
   
  Btw if anyone is on Facebook, they have a page. Get them more 'likes'!:
  http://www.facebook.com/pages/JustAudio/172902929412801?sk=info


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## cn11

Hah, yeah, it was some reaction I'm sure. It was also funny to have soozieq ask me 'well, what's it like?', and to have to say 'ummm.....it is markedly better than the Arrow'. Then to see her reaction to that because she had the Arrow right there and was in the middle of being amazed by it. All she could say was 'nooooo, dammit!'. That was really the most fun part of the meet for me- that sort of shock of an unexpected discovery.
   
  The Arrow is of course still an amazing and special little amp. And I think with its feature set currently there's no competition in the portable market at all. Especially if you want something with which you can add a touch of bass slam to more analytical sounding IEMs. I don't foresee selling either amp for a long time. 
   
   
   
   Quote: 





b0wl1ng said:


> It is a very good amp, I have one of the first ones produced, number 004 , where this amp really scores is in its detail, very precise and accurate,plus the built in Lithium battery is a real plus factor.





   
  That's awesome you have one of the first produced. I guess his amps have been relatively unknown around HF for almost a year or so. I hope that starts to change. It really is highly detailed, and the treble is just beautiful. Knowing how nice this one sounds, it makes me curious about how the bigger, class A 'AHA-120' sounds...... 
   
  My amp serial number is 18.


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## Kunlun

Quote: 





somnambulist said:


> It was fun seeing your reaction. It certainly did sound great with my stuff too and while I was dead-set on wanting an Arrow after hearing it slightly earlier in the meet, it's given me food for thought! It did sound larger, livelier, and as you've said elsewhere, the bass response felt like the Arrow 3G with the bass boost on +1. The only thing going against it for me would be the form-factor, as I think things like the TTVJ Slim and Arrow match the dimensions of most modern players better and make for an easier to pocket experience. That said, it's still not _that_ big.
> 
> Btw if anyone is on Facebook, they have a page. Get them more 'likes'!:
> http://www.facebook.com/pages/JustAudio/172902929412801?sk=info


 

 Could you compare the sound of this to the ttvj slim?


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## b0wl1ng

My thoughts exactly, if the uHA-120 is this good the class A , AHA-120 will probably be up alongside the best three, the Lisa, the Stepdance and the SR 71B.


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## Nuwidol

I listened to the AHA-120 (2 of them running parallel in balanced actually) driving the HE-6. I'm not joking here. One amp per channel can give the HE-6 a decent sounding presentation. I'd been listening to the HE-6 through the Lyr when Justin approached me & asked if I'd like to try his portable amps running them. I was a bit skeptical at first but after he'd set everything up & handed them back to me I sat there in disbelief. I actually preferred the HE-6 out of the 2 portables. They toned down that hard aggressive sound of the HE-6 & turned them into something a lot more forgiving.

 Well done to Justin for coming up with 2 great products. He's actually in the process of designing an amp for IEMs too (The UHA was made with full size cans in mind).


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## b0wl1ng

That is amazing, thought only a generator could power the HE-6s to full glory.


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## Somnambulist

Quote: 





kunlun said:


> Could you compare the sound of this to the ttvj slim?


 

 Haven't heard the TTVJ, sorry!


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## Jazzyfi

Great news! I'll wait for the IEM version of uHA-120. Hopefully something in that can compete with pico slim in terms of thinness.
  
  Quote: 





nuwidol said:


> I listened to the AHA-120 (2 of them running parallel in balanced actually) driving the HE-6. I'm not joking here. One amp per channel can give the HE-6 a decent sounding presentation. I'd been listening to the HE-6 through the Lyr when Justin approached me & asked if I'd like to try his portable amps running them. I was a bit skeptical at first but after he'd set everything up & handed them back to me I sat there in disbelief. I actually preferred the HE-6 out of the 2 portables. They toned down that hard aggressive sound of the HE-6 & turned them into something a lot more forgiving.
> 
> Well done to Justin for coming up with 2 great products. He's actually in the process of designing an amp for IEMs too (The UHA was made with full size cans in mind).


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## munkyballz

Haven't looked for my wallet yet, but I seriously need to stop reading these forums.  Even my imaginary wishlist is getting scared...


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## estreeter

Quote: 





munkyballz said:


> Haven't looked for my wallet yet, but I seriously need to stop reading these forums.  Even my imaginary wishlist is getting scared...


 
   
  Did you read about their plan to run TWO AHA-120s (the pure Class A amp that sells for over 600 USD) in balanced mode ? Run those numbers into your wishlist and tell us how scary the uHA-120 looks


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## munkyballz

^ Yeah I saw that blurb, but didn't read it too carefully because... well, I didn't want to remember it in the case I happen to win a mini lotto or something, as funds would definitely should be allocated elsewhere... haha.


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## edvardd

How is the sound signature of uHA-120? I havn't got a clear idea about your view, if its forward or midcentric? is there any part of the spectrum that is less emphasized? Thanks in advance


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## cn11

I think the uHA-120 is reasonably neutral really. No real coloration or signature. It has  really, really nice treble, with a true tactile and layered quality to it. The top end has wonderful sparkle. 'Crystalline' is a term I like to use to describe it. The mids are simply 'right'. They're neither too forward, nor too recessed. The bass is beautifully full, extended, and taut. I've been using the Lisa III w/power unit at work with my Ultrasones, and the uHA-120 definitely has deeper but more detailed bass, even when the Lisa's bass knob is turned up somewhat. 
   
  So, unfortunately, I don't really have a single descriptor for its sound signature. Detailed and accurate. Open and spacious. Full and robust as well. Nothing is less emphasized... it's all there in spades. Every box ticked.
   
  That's all I can offer!!   ;^)


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## edvardd

Thanks for you offer  I'm actually going to use it with Pro 900 too but perhaps with other cans too, such as Hifiman's upcoming more easily driven HE-500. Glad to hear that pro 900 sounds good with it.
   
  Ed
  Quote: 





cn11 said:


> I think the uHA-120 is reasonably neutral really. No real coloration or signature. It has  really, really nice treble, with a true tactile and layered quality to it. The top end has wonderful sparkle. 'Crystalline' is a term I like to use to describe it. The mids are simply 'right'. They're neither too forward, nor too recessed. The bass is beautifully full, extended, and taut. I've been using the Lisa III w/power unit at work with my Ultrasones, and the uHA-120 definitely has deeper but more detailed bass, even when the Lisa's bass knob is turned up somewhat.
> 
> So, unfortunately, I don't really have a single descriptor for its sound signature. Detailed and accurate. Open and spacious. Full and robust as well. Nothing is less emphasized... it's all there in spades. Every box ticked.
> 
> That's all I can offer!!   ;^)


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## dadab12

I think i'm going to order the uHA-120 this week. cnn observations and impressions really did the trick.


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## daveathall

I ordered this today, really looking forward to tomorrow.


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## cn11

Quote: 





daveathall said:


> I ordered this today, really looking forward to tomorrow.


 


  I don't see how you can't be pleased. It's a wonderful sounding amp. Please post some impressions once you get it. 
   
  Here's a pic for the interim.....


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## Kunlun

This seems as though it'd be perfect, but it's too big. I'm not really sure about the point of an amp that size. Technically transportable yet not truly portable in the sense of being too large to pocket and go with, so why not just make it larger?
   
  I wrote Justin about an iem amp and he was closemouthed about any work on an iem.
   
  Here's what he wrote:
I don't make a habit of talking about specifics on a possible future product or products or enhancements in the public domain. What I can say though, is that more attention is being given to better accommodating the IEM market in the future.  
   
  I like that it outclassed the arrow, though. Something smaller that outcompeted the arrow would be great, although I have a feeling it'll be a year until we see something like that if the e11 doesn't at least equal the arrow when it comes out (guessing at early-summer for that).


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## estreeter

Quote: 





nuwidol said:


> I listened to the AHA-120 (2 of them running parallel in balanced actually) driving the HE-6. I'm not joking here. One amp per channel can give the HE-6 a decent sounding presentation. I'd been listening to the HE-6 through the Lyr when Justin approached me & asked if I'd like to try his portable amps running them. I was a bit skeptical at first but after he'd set everything up & handed them back to me I sat there in disbelief. I actually preferred the HE-6 out of the 2 portables. They toned down that hard aggressive sound of the HE-6 & turned them into something a lot more forgiving.
> 
> Well done to Justin for coming up with 2 great products. He's actually in the process of designing an amp for IEMs too (The UHA was made with full size cans in mind).


 

 Aaaah, Head-Fi : I just spent a few posts defending Leckerton's $10 price rise, now I'm going to question what you have said on the basis of bang-for-buck 
   
  I agree that its impressive, but the cost of 2 AHA-120s would put you within reach of some very capable fullsize amps. Sure, you will be tied to a wall socket, but its difficult to argue for this as a solution for the HiFiMan orthos. Great proof-of-concept stuff, and I'm sure someone here will buy that configuration simply because they can, but its up there with shoehorning a 454 Chev V8 into a VW Bug - clever but expensive.


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## estreeter

Quote: 





kunlun said:


> This seems as though it'd be perfect, but it's too big. I'm not really sure about the point of an amp that size. Technically transportable yet not truly portable in the sense of being too large to pocket and go with, so why not just make it larger?


 

 Horses for courses, but you've just ruled a line through the RSA amps, most iBasso product and the Stepdance. For genuinely portable use, I agree that the slimline amps make more sense, but my T3 just didnt have the grunt of my D4 and doesnt begin to approach my P4 - that said, I accept 'transportable' over portable and my daily commute is a ten minute walk to work


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## cn11

It does seem very similarly sized to how I remember the RSA Mustang when I had it (maybe just a hair bigger). And that thing was considered highly portable a couple years ago. I guess all the slim amps now are spoiling us all on the uber-portable front.


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## Kunlun

Quote: 





estreeter said:


> Horses for courses, but you've just ruled a line through the RSA amps, most iBasso product and the Stepdance. For genuinely portable use, I agree that the slimline amps make more sense, but my T3 just didnt have the grunt of my D4 and doesnt begin to approach my P4 - that said, I accept 'transportable' over portable and my daily commute is a ten minute walk to work


 
  Right, I actually did rule out the stepdance for that reason, plus the battery issue. A 10 min walk is one thing, subways, trains, etc. are another. But yes, the mini-brick amps are transportable, just not really so comfortable to carry around all the time.

  
  Quote: 





cn11 said:


> It does seem very similarly sized to how I remember the RSA Mustang when I had it (maybe just a hair bigger). And that thing was considered highly portable a couple years ago. I guess all the slim amps now are spoiling us all on the uber-portable front.


 
  It's a good thing to be spoiled in this case, hopefully we'll see amps with how you describe the uha120's quality in the arrow's size sooner rather than later.


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## estreeter

Quote: 





kunlun said:


> It's a good thing to be spoiled in this case, hopefully we'll see amps with how you describe the uha120's quality in the arrow's size sooner rather than later.


 


  And that would bring the M-Stage down to something the size of my P4 - excellent. OK, so maybe I just bent the laws of physics, but dreams are free, right guys ? Er, guys ?  <crickets chirping>


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## Saintkeat

Where abouts in London can you try the uHA-120?
   
  I'd be willing to have a go the next time I drop by, might be later in the year as I'll be touring eastern europe in may.


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## Blasto_Brandino

Quote: 





estreeter said:


> Did you read about their plan to run TWO AHA-120s (the pure Class A amp that sells for over 600 USD) in balanced mode ? Run those numbers into your wishlist and tell us how scary the uHA-120 looks


 

 DAMN YOU!!! I'm thinking of doing it... Then I could run ANY (most any) Headphones anywhere I could trudge the amps.


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## cn11

Justin brought a couple examples to the recent UK meet in London. I'm not aware of any locations in London normally where you can demo them unfortunately. But he's located a ways north of the city:
   
   
http://maps.google.com/maps?q=154+High+Street,+Huntingdon,+Cambridgeshire+PE29+3TF&ie=UTF8&hq=&hnear=154+High+St,+Huntingdon,+Cambridgeshire+PE29+3,+United+Kingdom&gl=us&t=h&z=16
   
   
  You could always email him at justin@justaudio.com, however the site states "Please note that the company offers no on-site facilities for members of the public to visit the premises."


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## daveathall

Mine arrived this afternoon, Im highly delighted after a quick listen straight out of the box using some B&W P5s listening to The Poems “Young America“ and Roger Waters “Amused to Death“ from a iPod 160GB. As for the size, I have only had a Fiio E7 for comparison, which as most will know is much smaller, Im of the opinion that this amp, although larger, will be fine for mobile use. I will give a more in depth opinion when I have had it a bit longer.


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## Saintkeat

cn11 do you live in london then? perhaps I could entice you out for a cup of coffee when I'm down? I plan on meeting up with Parrots my next trip too.


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## cn11

Unfortunately I don't. I live in the US, in the midwest. I just happened to be in the UK for some vacation and was able to attend the UK meet. I demo'd the uHA there, and promptly bought the example from Justin.


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## Anaxilus

Hmmm, I was considering the massively powerful PB2 w/ balanced output and rollable opamps but the sonic impressions seem to be what I'm looking for as well.  A couple of things about the Stepdance that put me off were reports of dry mids and overly analytical signature along with the rounded case.  
   
  Any other impressions of the AHA v. UHA wrt signature comparisons?


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## daveathall

I'm delighted, makes my iPod sing like never before.
   
   
   

   
   
   
   

   
   
   
   

   
   
   
   

   
   
   
   
   

   
   
   
  I took out the Serial Number (Not sure why, but there ya go)


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## cn11

Congrats man. Looks great. I'm glad you're enjoying the sound so far. What are the phones you're using? I see a nice braided cable there, connected to the uHA.


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## daveathall

Thank you very much, I'm really made up,
   
  I am switching between some B&W P5s and Sennheiser IE8, the LOD is iBasso CB07


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## dadab12

It looks beautiful.
  what amps did you use prior to the uHA-120? and what are your impressions?


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## Kunlun

Gah, why can't this be 1/2" thinner?


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## Anaxilus

Quote: 





kunlun said:


> Gah, why can't this be 1/2" thinner?


 






   
  You could wear lifts?


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## Kunlun

Quote: 





anaxilus said:


> You could wear lifts?


 

 Gah, why can't I be 1" taller?


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## daveathall

Quote: 





dadab12 said:


> It looks beautiful.
> what amps did you use prior to the uHA-120? and what are your impressions?


 
   
  Thank you very much.
   
  I had a Fiio E7 for a very short time, I really didn't know that there could be such a pronounced difference between an iPod without amplification and with, the E7 spurred me on to buy the uHA-120 and some Sennheiser IE8s, and there was I, thinking that I would only be spending just over £60 when I bought the E7 lol. How much more mistaken could I be?
   
  I am new to this and find it very difficult to remember how something sounds when switching between one and the other, and also how best to describe those sounds/differences, but I found the uHA-120 to be clearer (cleaner?), different layers of the music previously unheard were discovered and the separation was more pronounced between instruments and artists. As for fit and finish I have nothing really to compare it with, I have not been lucky enough to see or listen to other portable amps in the same price range (or any price range for that matter) but it certainly is well screwed together with a tactile feel, the volume knob turns smoothly, the on indicator light glows a satisfactory yellow and the charging light turns from red to green on completion of charge.
   
  Bottom line is, I was and am really pleased with both amps. I sold the E7 to a friend for just shy of retail after he had the briefest of listens, for the money it is a fabulous device, but once bitten the future purchases it inspires will cost dear.
   
  I find myself sliding slowly down a slippery slope knowing that I can't quite reach the top to stop myself, having said that, I have the feeling that many reading this will be looking up at my descent while nodding knowingly.


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## Somnambulist

Thinking about the AHA-120 for my desktop (can just use an RCA-to-3.5mm from my D100, maybe even Just Audio's one: http://www.justaudio.co.uk/interconnects.html), given I've heard the uHA-120 and liked it a lot and it's less of a hassle to get here in the UK than some of the other things I was looking at, I don't need a whopping great amp and I can leave it connected to my USB hub rather than using another wall socket. Only quibble would be that the input's on the front and I want my wires hidden, but that's a very minor thing.


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## cn11

[size=medium]I hope you do wind up getting one. I leave it run via USB just as you describe quite often at work. No need for a wall adapter at all. Justin also tole me at the meet right before we took off that if you change the switch on the back of the amp from 'Batt' to 'USB' while having it connected, there's the added benefit of possible gains in headroom. I've played around with the switch listening for differences, and if there are any, it's a pretty small effect. Perhaps there's a hint of gain in air, but then again maybe it's my mind looking for differences. I do like knowing he is aware there could be improvements that way, and let me know about it though.
   
   ​[/size]


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## cn11

.  (double post)


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## Somnambulist

All out of stock at the moment (guess they must be popular, good to know!), can't see the interconnects for sale anywhere though. I'll probably drop Justin an email at some point about availability. Hopefully by the time I get to the stage where I want a portable amp (need my Focal monitors first!), his IEM one will be ready!


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## daveathall

Please excuse my ignorance, when talking about a mains adapter, would plugging it straight into the mains using an Apple usb charging plug suffice to charge the battery? I must admit that I am loathe to try in case I break my amp.


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## Somnambulist

Don't see why not, it's just an Apple branded adapter, not specific to charging only Apple stuff. I charge my S:Flo2 that way and it's quicker to charge than doing it on USB port on the computer because it's a little power hungry mofo and can suck more juice up that way.


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## b0ck3n

I'm in contact with Justin, working on some tweaks to best suit use with my Westone ES5. The guy is an absolute gem, wonderful to deal with and has really gone out of his way to accomodate my needs. I'm planning on getting an orthodynamic in the near future and might just get a second uHA-120 to run it balanced


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## Kunlun

I am looking for an amp with excellent extension above and below and mentioned to Mike at headfonia that if I couldn't find a smaller amp maybe I'd get the uha-120 despite its size. He said he's heard the aha-120 and that has a very mid-centric sound and his guess was that the uha-120 had the same sound sig, so I should avoid it...
   
  What do owners say?


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## cn11

Mid-'centric'?.... no. Mid-'correct'..... yes.


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## estreeter

I have only one objection - we cant have two prominent portable amp designers called 'Justin'. Its just (!) too confusing, and since Mr Wilson was here first, the other guy will need to change his name to something distinctive like 'Ray' or 'Jan'.
   
  Glad I could help.


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## Kunlun

Quote: 





cn11 said:


> Mid-'centric'?.... no. Mid-'correct'..... yes.


 

 Thanks, maybe the aha-120 has a different signature than the uha-120.


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## b0ck3n

Maybe he was listening to mid-centric headphones? Unless we measure frequency responses of all sources, headphones and amps it's going to be difficult to tell what exactly in the chain is coloring the sound.

  
  Quote: 





kunlun said:


> Thanks, maybe the aha-120 has a different signature than the uha-120.


----------



## Kunlun

Quote: 





b0ck3n said:


> Maybe he was listening to mid-centric headphones? Unless we measure frequency responses of all sources, headphones and amps it's going to be difficult to tell what exactly in the chain is coloring the sound.


 

 Have you ever checked out headfonia.com?
  Mike has a lot of audio under his belt.


----------



## b0ck3n

I have and I don't agree with everything he says, which isn't surprising as we all know how subjective audio is. I wasn't trying to imply that he's incompetent at all. I will soon find out for myself if the uHA-120 is mid-centric, perhaps it is.


----------



## Kunlun

Quote: 





b0ck3n said:


> I have and I don't agree with everything he says, which isn't surprising as we all know how subjective audio is. I wasn't trying to imply that he's incompetent at all. I will soon find out for myself if the uHA-120 is mid-centric, perhaps it is.


 

 No worries, I'd like to hear your impressions when you receive it.


----------



## estreeter

Not sure if this has been pointed out previously, but the stated prices on the website and at hifiheadphones UK seem to include VAT - those of us who live outside the UK pay less. Long story short, to have the uHA-120 (with optional Vishay pot) *delivered to my door here in Oz has cost me the princely sum of 305 AUD.* What I had previously disregarded as an 'expensive' amp now slots neatly in just above the iBasso D12 (about $290 delivered) and several of Ray's amps (mid 350s delivered), and well below the Stepdance at $399 locally.
   
  Its nice to be pleasantly surprised by the total cost of a portable amp. Rare, but nice.


----------



## i_djoel2000

Quote: 





estreeter said:


> Not sure if this has been pointed out previously, but the stated prices on the website and at hifiheadphones UK seem to include VAT - those of us who live outside the UK pay less. Long story short, to have the uHA-120 (with optional Vishay pot) *delivered to my door here in Oz has cost me the princely sum of 305 AUD.* What I had previously disregarded as an 'expensive' amp now slots neatly in just above the iBasso D12 (about $290 delivered) and several of Ray's amps (mid 350s delivered), and well below the Stepdance at $399 locally.
> 
> Its nice to be pleasantly surprised by the total cost of a portable amp. Rare, but nice.


 

 hi estreeter, is uha120 using the same case as in amb mini3? they look similar to me..
   
  and, anybody noticed significant difference of upgrading the volume pot to vishay p11?


----------



## Jazzyfi

Hey b0ck3n, did you get your uHA-120 already? Did you ask Justin to lower the gain to match the ES5? Any tweaks regarding output impedance?
  
  Quote: 





b0ck3n said:


> I'm in contact with Justin, working on some tweaks to best suit use with my Westone ES5. The guy is an absolute gem, wonderful to deal with and has really gone out of his way to accomodate my needs. I'm planning on getting an orthodynamic in the near future and might just get a second uHA-120 to run it balanced


----------



## b0ck3n

I had to jump ship on the uHA-120. Justin was kind enough to try some tweaks that he thought of offering as a standard mod, which involved cutting gain in half and lowering output impedance to 1.1 Ohm.

  
  Quote: 





jazzyfi said:


> Hey b0ck3n, did you get your uHA-120 already? Did you ask Justin to lower the gain to match the ES5? Any tweaks regarding output impedance?


----------



## Jazzyfi

I hope that lowering the output impedance won't give any hiss to ES5. iQube has crazy low output impedance of 0.1 ohm to 1.5 ohm at 20KHz but the disadvantage is the white noise (hiss).
  Let me know how do you like it once you get it. I might order it as well to pair it with my upcoming SE5 and FX700.
  
  Quote: 





b0ck3n said:


> I had to jump ship on the uHA-120. Justin was kind enough to try some tweaks that he thought of offering as a standard mod, which involved cutting gain in half and lowering output impedance to 1.1 Ohm.


----------



## b0ck3n

He managed to lower output impedance without use of any resistors, so it shouldn't affect the noise floor in any way but rather just limit the effect on frequency response. It did however cause instability under some circumstances, which would waive warranty.


----------



## Jazzyfi

Hmm.. might have something to do with low battery voltage.. or does it have something to do with fast rising edge? Then it might be easily solved by extra caps in the feedback loop.. But I'm guessing too much 
	

	
	
		
		

		
		
	


	




. I'll just wait for your impression.


----------



## Jonasklam

i'm really interested in the amp, but what is the point of the vishay p11?
  I don't get it.


----------



## estreeter

Quote: 





jonasklam said:


> i'm really interested in the amp, but what is the point of the vishay p11?
> I don't get it.


 

 Which part dont you get ? A better potentiometer theoretically equals better volume control, and thats particularly important for people who own sensitive IEMs. I'm sure the more technically minded can give a better explanation, but thats my take on it.
   
  Anyway, mine just arrived, complete with the aforementioned P11 'upgrade'. Nano in one end and KSC-75s out the other, I'll just leave it to run throughout the work day and start listening  tonight.
   
  To the guys at HiFiHeadphones UK, thanks for your efforts, but that seems like a hell of a lot of packing for such *a tiny amp*. When I first saw the box, I had to wonder if you had accidentally sent me something else (!) but somewhere in the bubble wrap there was a small white box with an even smaller amp inside. Very attractve casework lives up to the photos on the website.
   
  I have taken some photos to give people an idea of the size, but the thickness relative to the slimline amp will be the big sticking point for many - personally, anything smaller than the D4/P4 seems tiny by comparison. Will post the photos tonight.


----------



## frenchbat

Congrats Estreeter ! Glad the first impression is the right one for you. I'm waiting for my AHA today too, should be the same here.


----------



## Jonasklam

Quote: 





estreeter said:


> Which part dont you get ? A better potentiometer theoretically equals better volume control, and thats particularly important for people who own sensitive IEMs. I'm sure the more technically minded can give a better explanation, but thats my take on it.
> 
> Anyway, mine just arrived, complete with the aforementioned P11 'upgrade'. Nano in one end and KSC-75s out the other, I'll just leave it to run throughout the work day and start listening  tonight.
> 
> ...


 

 Thanks for the explainaination. But seriously, how hard can it be to control volue, you turn and it goes up or down. I'm not trying to be arrogant, just trying to understand and learn.
  Maybe the vishay p11 = equals more positions on the volue pot? For eksample, the normal pot could have 30 "positions" where the vishay have 45 "positions" giving you better control over the sound? Is that how it works?
   
  Also, I read on headfonia that the AHA-120 had a small channel imbalace issue at low level, but disappeared at listening level. And since the AHA-120 uses the vishay as well, i figured it might be due to that? I may be waaay off here?
   
  Anyway, can you check on your amp, when you have the time, if there any imbalances between left and right channel at very low levels?
  It is becuase I normally listen to music at very low levels and this statement from headfonia concerns me a bit.
   
  Anyway, congrads on your amp! I hope you find it awesome


----------



## frenchbat

With sensitive IEM you may get some channel imbalance at low listening level, that's why a quality pot is necessary. Vishay is such a quality pot, or you can also get a digital controlled pot like on the Pico Slim.


----------



## estreeter

I wouldnt spend too much time worrying about anything Mike writes on Headfonia, but by the same token I dont think the *AHA-120*, a full class A amp, is aimed at the owners of sensitive IEMs, even if Mike used a couple of pairs of earphones in his review. Personally, I would be a lot happier if Justin could make the difference between his amps more instantly recognisable - I would have called the Class A amp the 'AHA-160' or 'Megatron' : anything to differentiate it from its considerably smaller sibling.
   
  In my case, the most sensitive IEM I own just isnt going to be close to the high end kit that people report problems with 'hiss', and I have never been particularly worried by that anyway. The amp would need to have a particularly obvious problem for me to complain about that, but others here seem extremely sensitive to any hiss at any volume level.
   
  Seriously, if you are intent on listening at very low volumes, I suspect one of the slimline amps from Todd or Justin W might be a better fit than a Class A design which is throwing away a milliWatt for every 2mW it generates - happy to hear otherwise.


----------



## estreeter

The photo, as promised - more photos coming later as I put my review/comparison together. I believe it is both narrower and shorter than the uHA-4 - hardly the Goliath that some seem to think from the website photos:


----------



## kaushama

cool stuff! What is the player next to it? HOw does it sound?


----------



## estreeter

6G Nano, and it sounds good, but I wont be posting anything more until I've spent time actually listening to it for an extended period. Burn-in skeptics have a field day with initial impressions vs those given a few days or weeks later. I'm still blown away by the size, and wondering if I should have gone whole hog and bought the A-class AHA-120. The smaller amp will easily slot into the same camera case I am currently using for the uHA-4.


----------



## b0ck3n

Here's what Justin said wrt the different volume pot options:
   
  "The current version of the P11 is top quality after some further modification by myself to get the feel right, but the taper is unfortunately too quick for high sensitivity IEMs, since it was set-up for headphones. The standard volume control is better in this sense..."


----------



## estreeter

Thanks for the clarification - it would appear that I had it 180 degrees around the wrong way ! Fortunately (!), I dont have any JH16Pro type earphones waiting at home. Really looking forward to getting some time alone with my new toy tonight.


----------



## Jazzyfi

A potentiometer is not something so simple to make, especially to get a matching resistant between 2 channel. There are always certain tolerance depending on the process. The more expensive they get the smaller the tolerance. A potentiometer is a mechanical device, so there is no feedback to self adjust the channel imbalance/resistant value. What the designer can do is to read the value of the pot and do some balancing by changing the gain of the amplifier to compensate the tolerance of the amplifier. This will cost the designer a lot of time and money because if you are not careful/good you can get instability by changing the gain/feedback of the amplifier.
   
  And one more point: a potentiometer attenuate the input so it can be amplified with certain gain. So actually what you are doing by lowering the volume is to attenuate your input signal (which will make your signal worse depending on the pot) and not changing the gain of the amp. However there are other technique by actually putting the pot in the opamp circuitry (or the discrete circuitry if opamps are not used) itself to change the gain of the amp. This is more difficult/risky way to get a stable amp.
   
  Hope you can get the point that making a good amplifier is a tough job. Too many parameters to deal with.
  Quote: 





jonasklam said:


> Thanks for the explainaination. But seriously, how hard can it be to control volue, you turn and it goes up or down. I'm not trying to be arrogant, just trying to understand and learn.
> Maybe the vishay p11 = equals more positions on the volue pot? For eksample, the normal pot could have 30 "positions" where the vishay have 45 "positions" giving you better control over the sound? Is that how it works?
> 
> Also, I read on headfonia that the AHA-120 had a small channel imbalace issue at low level, but disappeared at listening level. And since the AHA-120 uses the vishay as well, i figured it might be due to that? I may be waaay off here?
> ...


----------



## Jonasklam

Quote: 





b0ck3n said:


> Here's what Justin said wrt the different volume pot options:
> 
> "The current version of the P11 is top quality after some further modification by myself to get the feel right, but the taper is unfortunately too quick for high sensitivity IEMs, since it was set-up for headphones. The standard volume control is better in this sense..."


 

 Cool mate, thanks for that


----------



## Jonasklam

Quote: 





jazzyfi said:


> Hope you can get the point that making a good amplifier is a tough job. Too many parameters to deal with.


 
   
  Yep I do, but keep in mind, I ain't trying to bash the Amp or it's maker. I just want to make sure I do the right thing if I go ahead and purchase one of these. I wanted two fully understand the differences between the two pots.


----------



## b0wl1ng

Quote: 





estreeter said:


> Thanks for the clarification - it would appear that I had it 180 degrees around the wrong way ! Fortunately (!), I dont have any JH16Pro type earphones waiting at home. Really looking forward to getting some time alone with my new toy tonight.


 

 Hi Buddy, what is your batch number ?, I had one of Justins earlier amps 004, it is a great little all rounder, very musical and powers all my cans from very low to tough to drive orthos.
  A particularly good match with my senn 650s, the built in battery is a real plus .


----------



## Jazzyfi

I tried the 6G Nano 2 days ago. It was fantastic! This might be my next super portable rig. Nano + uHA 120 + FX700/ES5.
  
  Quote: 





estreeter said:


> 6G Nano, and it sounds good, but I wont be posting anything more until I've spent time actually listening to it for an extended period. Burn-in skeptics have a field day with initial impressions vs those given a few days or weeks later. I'm still blown away by the size, and wondering if I should have gone whole hog and bought the A-class AHA-120. The smaller amp will easily slot into the same camera case I am currently using for the uHA-4.


----------



## estreeter

Quote: 





b0wl1ng said:


> Hi Buddy, what is your batch number ?, I had one of Justins earlier amps 004, it is a great little all rounder, very musical and powers all my cans from very low to tough to drive orthos.
> A particularly good match with my senn 650s, the built in battery is a real plus .


 
   
  I havent even checked the back of the amp, other than to recharge it - never been big on serial numbers and the like.
   
  Re. the earlier discussion on channel imbalance, regrettably it would appear that the observations made by Justin and others are correct : even to my cloth-like ears, the imbalance is obvious at the first 'listenable' setting on the pot. Beyond that, its fine, but when I tried the same exercise with the Leckerton amp two things became obvious:
   
  - no channel imbalance at very low volumes, at least as far as I could tell - younger Head-Fiers may be have different feedsback, but anyone listening at volumes that low has to ask whether they need an amp or just a better source
   
  - the Leckerton has much finer control over volume increments courtesy of its 'pump' style pot. The uHA-120 isnt 'all or nothing', but you dont have far between 'just audible' and 'pleasant listening level' : a clear point of difference between the two.
   
  That said, the uHA-120 seems to have more power on tap, and I dont listen at anything beyond 11am with any of my cans. The uHA-4 does have a gain switch, but I find it makes the sound more aggressive - for some of my music thats fine, but after a day at the office, its just too 'in your face' for me.


----------



## estreeter

A couple more photos to illustrate relative sizes (please do NOT quote the images in the interests of folk on mobile phones etc) :
   
  1. Fiio E9 piggybacked by Leckerton uHA-4 (middle) and Just Audio uHA-120 (top)
   

   
  2. Side view of same, with iBasso T3 on top.

   
  Looking at these photos, its tempting to think 'Whoa ! The E9 is *huge* !', but its not - you could easily carry that amp to a meet in a backpack or satchel and barely even be aware of it most of the time - it weighs half a kilo (roughly one pound). The other amps are completely 'portable' IMO, but the 'thin is in' crowd on HeadFi will undoubtedly disagree when they see how thick the casing is on Justin's amp. Thats showbiz.
   
  (Apologies for my crap photography, but I hope it gives some a better idea of the size of the uHA-120).


----------



## kaushama

Quote: 





> Originally Posted by *b0ck3n*
> 
> 
> 
> ...


 
   
   
  I contacted Justin and inquired before ordering the amp about IEM usage. I am planning to use it both Westone 4 and HD650. Justin offered me a version with internal gain header jumpers to make the gain 6DB and 10DB. I am waiting for that. If you go for this custom made version one has to buy it directly from Justin currently.


----------



## munkyballz

Quote: 





estreeter said:


> A couple more photos to illustrate relative sizes (please do NOT quote the images in the interests of folk on mobile phones etc) :
> 
> Looking at these photos, its tempting to think 'Whoa ! The E9 is *huge* !', but its not - you could easily carry that amp to a meet in a backpack or satchel and barely even be aware of it most of the time - it weighs half a kilo (roughly one pound). The other amps are completely 'portable' IMO, but the 'thin is in' crowd on HeadFi will undoubtedly disagree when they see how thick the casing is on Justin's amp. Thats showbiz.
> 
> (Apologies for my crap photography, but I hope it gives some a better idea of the size of the uHA-120).


 

 Thanks for the pics.  The uha-120 is actually smaller than I thought it would, still a little chub, but in return, probably a lot to lub, I meant love.  Looking forward to hearing future impressions and the inevitable comparo between the two.


----------



## b0ck3n

I would advice asking for a low output impedance version. It'll do wonders for your W4 (or rather, keep it from messing its FR up).

  
  Quote: 





kaushama said:


> I contacted Justin and inquired before ordering the amp about IEM usage. I am planning to use it both Westone 4 and HD650. Justin offered me a version with internal gain header jumpers to make the gain 6DB and 10DB. I am waiting for that. If you go for this custom made version one has to buy it directly from Justin currently.


----------



## b0wl1ng

Quote: 





estreeter said:


> Just wondered how many have been sold as they appear to be very popular now, hence the serial number question.
> I havent even checked the back of the amp, other than to recharge it - never been big on serial numbers and the like.
> 
> Re. the earlier discussion on channel imbalance, regrettably it would appear that the observations made by Justin and others are correct : even to my cloth-like ears, the imbalance is obvious at the first 'listenable' setting on the pot. Beyond that, its fine, but when I tried the same exercise with the Leckerton amp two things became obvious:
> ...


----------



## daveathall

I concur, there is an imbalance at the very lowest level on my uHA-120, for me it really is a non issue, I cannot foresee any occasion where I would listen to any music at such a low level, it really is only on the first switch on setting, I think that this amp is so good that I can forgive it this foible, I generally use mine between 10 and 11 through IE8s and Audeze LCD-2s. It is smaller than it seems on photo's, so much so, like a previous poster, I sometimes wish I had gone for the slightly larger model.
   
  I hope Justin brings out a DAC at some stage, I would be very keen to match it with this amp.
   
  By the way it is one of the early ones (0008) I'm really delighted with it.


----------



## Jonasklam

Quote: 





daveathall said:


> I concur, there is an imbalance at very low level on my uHA-120, for me it really is a non issue, I cannot foresee any occasion where I would listen to any music at such a low level, it really is only on the first switch on setting, I think that this amp is so good that I can forgive it this foible, I generally use mine between 10 and 11 through IE8s and Audeze LCD-2s.


 
   
  Cool, just what I needed verified.
  Maybe I should go for another amp, since I normally listen at low volume, or maybe a better source?


----------



## estreeter

Mine has serial number 16 stamped on the back (ok '00016', or whatever, but I cant remember how many zeroes preceeded the number 16). I assume that HiFiHeadphones bought an early batch from Justin - Robin told me that they had done their homework prior to adding his amp to their website and were suitably impressed.


----------



## LzaH

Hey guys, just popping in for a quick question. To whoever has one with the Vishay pot, is the amp very loud when using IEMs, especially customs? Like, a 'slight turn and you blow your ears off' type of loud? Thanks!


----------



## b0ck3n

fI think you'll be fine. Ask for the 6db gain version, the lowest volume settings will essentially make the amp an attenuator.
  
  Quote: 





jonasklam said:


> Cool, just what I needed verified.
> Maybe I should go for another amp, since I normally listen at low volume, or maybe a better source?


----------



## estreeter

Quote: 





lzah said:


> Hey guys, just popping in for a quick question. To whoever has one with the Vishay pot, is the amp very loud when using IEMs, especially customs? Like, a 'slight turn and you blow your ears off' type of loud? Thanks!


 
   
  Yes - under no circumstances should you buy the Vishay version of this amp, or any version of the iBasso P4. Your head could easily explode.


----------



## LzaH

estreeter said:


> Yes - under no circumstances should you buy the Vishay version of this amp, or any version of the iBasso P4. Your head could easily explode.





Hmm, I see.. How about with the standard pot? Even worse? If it is, I guess I'd better wait for the IEM version..


----------



## estreeter

Did you read the page before this in this thread ? We discussed this extensively, including a quote from the amp's designer.


----------



## LzaH

Oh whoops, how did I skip Page 6.. Thanks.


----------



## Jazzyfi

Hey b0ck3n, when will you get your uHA-120? I hope soon. You can be the reference for people using ES stuffs. hehe.


----------



## daveathall

I use it with IE8s, works great.


----------



## Jonasklam

Quote: 





b0ck3n said:


> fI think you'll be fine. Ask for the 6db gain version, the lowest volume settings will essentially make the amp an attenuator.


 
   
  Thanks man, i'll ask Justin for that if I purchase.
   
  Should I go for the vishay pot then? Or not? Since Justin's quote (page 6) didn't recommend the vishay, but with lower gain, it might be better?


----------



## Jazzyfi

I don't think so. It has something to do with the tapper which influence the volume jump.
  
  Quote: 





jonasklam said:


> Thanks man, i'll ask Justin for that if I purchase.
> 
> Should I go for the vishay pot then? Or not? Since Justin's quote (page 6) didn't recommend the vishay, but with lower gain, it might be better?


----------



## Jonasklam

Quote: 





jazzyfi said:


> I don't think so. It has something to do with the tapper which influence the volume jump.


 

 So stadard pot with the lower 6dB would be better for low volume listening with IEMs?


----------



## Jazzyfi

Yes. Supposed to. Let me know how it is when you got it. I'm really curious between this and leckerton.
  
  Quote: 





jonasklam said:


> So stadard pot with the lower 6dB would be better for low volume listening with IEMs?


----------



## b0ck3n

The Vishay takes too big volume jumps for IEMs. Standard pot and 6db gain + a lowered output impedance, if Justin still offers this, would be ideal.


----------



## Paul Meakin

Dave,
   
  How is it with the LCD-2s? Justin convinced me that my AHA-120 will drive them more than loud enough, but does it do them justice? e.g. compared to a powerful desktop amp like the Violectric V200?
   
  Please be careful before you answer as you're potentially going to cost me £800... 
	

	
	
		
		

		
			





 I'm currently using HD-650s and the AHA-120 drives them really well, it has great control and gives fast, tight bass.
   
  Paul
   
  Quote: 





daveathall said:


> I concur, there is an imbalance at the very lowest level on my uHA-120, for me it really is a non issue, I cannot foresee any occasion where I would listen to any music at such a low level, it really is only on the first switch on setting, I think that this amp is so good that I can forgive it this foible, I generally use mine between 10 and 11 through IE8s and Audeze LCD-2s. It is smaller than it seems on photo's, so much so, like a previous poster, I sometimes wish I had gone for the slightly larger model.
> 
> I hope Justin brings out a DAC at some stage, I would be very keen to match it with this amp.
> 
> By the way it is one of the early ones (0008) I'm really delighted with it.


----------



## daveathall

Hi Paul, my uHA-120 drives them easily, IMHO it more than does the LCD-2s justice. I take it you are in the UK? I auditioned mine first at Stockton on Tees with my portable stuff, it may be worth a drive, depending where you are for an audition before laying out 800 quid. Im afraid I haven't heard any powerful desk amps, that pleasure and wallet pain is yet to come.


----------



## Paul Meakin

Hi Dave, yes I am in the UK, but down near the South coast; 7 miles further south and I'm in the English Channel. Stockton was a fairly long way when I used to live in Leicestershire, and that's now three hours or so North...
   
  I'll probably take the plunge before too long anyway; it's only money, and you can't take it with you, so it's best to enjoy it while you can!
   
  I really appreciate the feedback, not too many people seem to have the LCDs with one of Justin's amps.
   
  Paul
  
  Quote: 





daveathall said:


> Hi Paul, my uHA-120 drives them easily, I take it you are in the UK, I auditioned mine first at Stockton on Tees with my portable stuff, it may be worth a drive, depending where you are for an audition before laying out 800 quid. Im afraid I haven't heard any powerful desk amps, that pleasure and wallet pain is yet to come.


----------



## estreeter

Quote: 





daveathall said:


> Hi Paul, my uHA-120 drives them easily, IMHO it more than does the LCD-2s justice. I take it you are in the UK? I auditioned mine first at Stockton on Tees with my portable stuff, it may be worth a drive, depending where you are for an audition before laying out 800 quid. Im afraid I haven't heard any powerful desk amps, that pleasure and wallet pain is yet to come.


 
   
  I'm confident that the E9 would do a better job with the LCD-2, but you are tied to a wall socket and a bloody ugly wallwart PSU. The good news is that there wont be a lot of wallet pain.


----------



## FreeBlues

I tried an early model uHA-120 with custom IEM's (UE-11's) AND the new ALO CLAS, a device that seems to send a very, very hot signal to the amp.  The volume was 'blow your ears off" at a volume level just above zero.  I loved what I heard, but the amp was simply too much.  In fairness, even the StepDance was almost too much as well with this rig.
   
  I've been in communication with Justin since and he has sent me an IEM version of the amp, much lower gain.  If y'all can wait a few days I'll most definitely be reporting results.
   
  Let me say in addition, Justin has been well beyond fantastic to deal with, BY FAR the most responsive, thorough and helpful guy I've ever encountered in this hobby.  I can't say it's a good thing if everybody starts slamming him with emails - takes way too much time away from what he does best! - but i would encourage some judicious inquiries if you have special needs.


----------



## Paul Meakin

Hi estreeter,
   
  Dave was replying to my question, and I already have the AHA-120. I doubt if the E9 is the right option for me.
   
  I'm trying to figure out if I stop where I am (iPod 160G Classic - CLAS - AHA-120 - HD650) or go down the route of LCD-2, plus a more powerful amp (V200) plus most likely a desktop DAC (I'm leaning towards a Wyred4Sound DAC-2)... around £2800 more outlay in total, and no longer portable. This is serious money, and I don't want to spend it unless I'm going to get a significant improvement.
   
  @FreeBlues, I agree that the CLAS is 'hot'. Seemingly both regarding output level, and overall sound characteristics compared to what I'm used to from my full-sized hi-fi system.
   
  It may be a system balance problem with my iPod/CLAS/AHA-120/HD-650 all re-enforcing similar characteristics, but I know that something sounds wrong on many of the tracks I listen to... it sounds too harsh/processed/'digital' even with the iPod EQ set to 'Deep' which really rolls off the treble.
   
  Good recordings sound terrific, but my current set-up is very unforgiving of poor recordings, and really good systems tend to improve the worst recordings (making them sound acceptable), while shining with the best recordings.
   
  Any thoughts from you or anyone else would be really appreciated; this equipment is really difficult to audition and I don't want to waste (a lot of) money.
   
  Paul
  
  Quote: 





estreeter said:


> I'm confident that the E9 would do a better job with the LCD-2, but you are tied to a wall socket and a bloody ugly wallwart PSU. The good news is that there wont be a lot of wallet pain.


----------



## Somnambulist

Have you got a pic of your triple stack? (iPod, CLAS and AHA-120) I've seen and used the uHA-120 at the UK meet but didn't spot it's bigger brother.
   
  I look forward to Justin doing an IEM-centric amp (as these two are undoubtedly headphone amps in their stock config) as I loved what I heard from the uHA-120.


----------



## estreeter

Can someone give me an estimate of how many hours play time they are getting from a 'full' charge ? Thus far, I seem to be recharging mine a little more often than I'd like to. I guess there is  price to be paid for the glorious bass after all.


----------



## kaushama

Justin's site says it works for 24hrs after a single charge. Isn't that what you get? At least close?


----------



## Paul Meakin

Somnambulist,
   
  No picture at present, but the AHA-120 is just a slightly bigger footprint than the CLAS and around 50% higher/thicker.
   
  The iPod Classic is again slightly smaller and thinner than the CLAS.
   
  The iPod stacks on top of the CLAS which is on top of the AHA, and they each get slightly bigger and thicker towards the bottom of the stack. So it's quite solid.


----------



## Paul Meakin

My iPod and CLAS both run down much faster than the amp, and it gets charged when one of them runs out of power; which I guess is only 6 hours or so.
  Quote: 





estreeter said:


> Can someone give me an estimate of how many hours play time they are getting from a 'full' charge ? Thus far, I seem to be recharging mine a little more often than I'd like to. I guess there is  price to be paid for the glorious bass after all.


----------



## estreeter

For those who dont have the amp. this is what happens during charging:
   
  1. Plug the amp in via USB and the light at the rear of the amp is cherry red
  2. After a period (an hour or two, best guess), it changes to orange
  3. Finally, it changes to green and that's when I start using it from the battery
   
  I am getting about 12-14 hours from a charge, but I may not be leaving it on the charger long enough. My amp came in a small white box with nothing else - no manual. For the sake of illustration, this is the FAQ from Justin's site (I would have liked a printed manual - even Leckerton managed an A4 page - I wont even start on the Jays manual):
   
_(1.) How long does the internal battery last?_
_For the uHA-120 operation time is up to 24 hours; Whereas, for the AHA-120 the operation time depends on the class A current biasing; the longest time is around 60 hours when using 600 ohm headphones, whereas this drops to around 18 hours when using the preset for 32 ohm headphones._
   
_(2.) What does the AHA-120 headphone selector adjust?_
_This selects a defined amount of current to ensure that the amplifier keeps operating in class A mode. Lower impedance headphones require more current, so the lowest impedance preset has the highest current consumption. And if the amplifier is required to provide more output current than the preset allows, then it simply reverts back to class AB operation and will work in this mode right up to the point where the current limiting kicks in._
   
_(3.) The amplifiers only specify a minimum impedance of 32 ohms, does this mean that lower impedance headphones/IEMs cannot be used?_
_This is rarely the case. The amplifiers are tested at 60mW(rms) continuous output into 32 ohms with both channels driven. This is more than enough for the majority of cases, in fact for ultra sensitive IEMs maximum levels of a just over a milli-watt (1 thousandth of a watt) are more than sufficient. _
   
_(4.) Why are there two settings for charge rate, why shouldn’t I just use the ‘fast’ charge rate all the time?_
_With the High speed USB standard, there is a 500mA limit to the amount of current that a port can supply. In some cases the USB supply may not be able to provide much current, so by using the ‘normal’ charge rate option the end-user can ensure compatibility with less capable USB power sources. _
   
_(5.) What's a volume pot upgrade?_
_The volume potentiometer is what the user turns to adjust the volume level; So with the Vishay pot upgrade, you are buying a a higher specification custom made part from France, which specifies a tighter channel tracking over the standard volume control pot. The feel is also different, as the standard volume has a viscous damped feeling that becomes more fluid in warmer conditions and the integrated power switch mechanism makes an audible click; whereas the P11 has a stable silky feel and the integrated power switch hardly makes any sound._
   
_(6.) I want to use one of your amplifiers with my IEMs, but will the volume adjustment be okay? As with my current amplifier I can not turn the volume any more than the 8 o’clock position before the music becomes too loud!_
_This depends on the sensitivity and impedance of the IEMs, so please provide the make and model when placing an order, so that we can advise further. Also, as of April 2011 we are now offering a maximum gain of 6dB (x2) version of both uHA-120 and AHA-120 products sold direct as custom orders, to ensure better compatibility with more sensitive IEMs._
   
  Note the late addition re sensitive IEMs.
   
  For those who feel I am nitpicking, note that I would rather have a great amp with no manual than the inverse. Apologies if there was a manual and it simply wasnt included in my package.


----------



## kaushama

I have got my 6DB/10DB header version of uHA-120. As Justin suggested it has the standard volume pot, which gives very smooth control over the volume with my Westone 4. It sounds very good. More details about its performance  against latest versions of Xin amps and amp section of D10 would be forthcoming. In short it is a neutral and very transparent amp, which has very tight bass control with great punch!


----------



## estreeter

Good stuff, kaushama. I finally plugged the PL50 and the a-Jays 3 into my Vishay-equipped 120 this morning, and it really is 'zero-to-one-hundred' in a single turn of the pot. Glad to hear that the stock pot is a better match for sensitive IEMs - this amp deserves a wider audience, even if its blocky casing will turn a lot of the slimline crowd away.


----------



## kaushama

Size may be a factor to keep the crowd away from this amp. I think the thickness comes from the height of the volume pot. Justin should design one with digital volume control to get the size down, to fit it to tastes of the crowd, who are concerned about size. But any day, I would pick it up as quite a portable amp against many other competitors, which have the sound quality of its league.


----------



## Somnambulist

Well there was a mention of a IEM-centric amp coming out eventually. I imagine that it would probably be a little more pleasing dimension-wise to most, although having used the uHA it's not really that big. Macro shots of gear on Head-Fi always make stuff look nice but a little larger than it really is!


----------



## estreeter

Quote: 





somnambulist said:


> Well there was a mention of a IEM-centric amp coming out eventually. I imagine that it would probably be a little more pleasing dimension-wise to most, although having used the uHA it's not really that big. Macro shots of gear on Head-Fi always make stuff look nice but a little larger than it really is!


 

 Said 'mention' came from a Head-Fier - my read of Justin's response was that he wasnt willing to commit to the production of said 'IEM-centric' amp : always happy to hear otherwise.


----------



## Somnambulist

I think that was someone who went to the UK meet and actually talked to Justin, his reply to someone's online enquiry was "we won't talk about stuff till it's available".  I think.


----------



## Mute-on

Hi All,
   
  First post after a while viewing.  This has been prompted by my recent purchase of a uha-120 with the Vishay volume pot.
   
  I actually had Justin perform the high/low gain mod on my sample.  A genuinely nice guy who is obviously more than enthusiastic about both his own products and headphone audio in general.
   
  Even at the low gain setting (6dB.  High is 12dB!) it drives my Beyer DT 250 80ohm with ease.  Comfortable low level listening at no more than 9 o'clock.  The reason Justin suggested this setting was to use with the output of my M2Tech Young DAC, which I just tried.
   
  Playing Red Book through Macbook Pro > M2Tech > uha-120 > AT AD900 the sound through the uha at no more than 9.30 on the dial  was AMAZING!!!
   
  Totally balanced, tight deep bass (yes on the AD900), solid attack, full midrange, shimmering treble (no sibilance), excellent depth and soundstage.  Honestly, though I have no other amps to compare the uha to, I can't imagine a significantly better presentation to my ears, at least in so far as you get the overwhelming impression that what you are hearing is simply what's on the original recording.  Nothing is exaggerated and nothing is left wanting.
   
  Clearly the source has a lot to do with the final sound, and all I can say is any deficiency is more likely a result of poor source than Justin's little uha-120.  It compares more than favourably with my Naim pre-power and 2.1 stereo (10" sub and studio monitors).  I've also tried it fed by iPod Touch alone, and iPod Touch > Pure i20 (internal DAC) > DT250/AD900. In all cases, Justin's amp showed up the limitations of the source and clearly improved on the unamplified arrangement.  
   
  In short a transparent, balanced and highly musical amp.  Now all I need is a pair of LCD-2 or HE-500 to justify owning it ... 
   
  Just my 2c, anyway.


----------



## estreeter

I agree that the amp works well with the AD900, but I hope you were joking about the HE-500. Big difference between being able to get reasonable volume levels out of something like that and being able to drive them with authority - just my 2 cents worth. LCD-2 would be closer to the mark, but I'd still prefer a desktop amp for any of those cans.


----------



## RobinHiFi

We received a new batch of the Revision B uHA-120 amps at HiFi headphones earlier this month. Justin has tweaked the design slightly to allow the end user select one of two maximum gain presets along with providing a tool kit needed to disassemble and select the desired maximum gain. He has made some other slight refinements to make it easier to open the amp (assuming that you know how to use a hex key). Full details of the changes along with a handy jumper setting guide are on the uHA-120 product features page - http://www.justaudio.co.uk/uha-120.html. He has also created an online sound pressure level estimator, which he hopes will be useful, since it should help to provide some estimate of perceived loudness for different headphones/IEMs - http://www.justaudio.co.uk/tools.html.

 Due to lack of availability of the customised Vishay  P11 volume pot (remaining parts reserved for AHA-120), we are stocking the standard professional audio pot version. What is surprising however is how good these are in terms of the feel, channel balance and low level adjustment. Justin has told us that he is quite amazed how good these are and he grades these himself to guarantee better than 1dB channel balance for custom orders in place of P11 (P11 throw is really too short for IEMs).

 Anyway Justin asked us to check over one of Revision B amps, to (a) see how we found the process of changing the maximum gain preset and (b) also check the sound quality and confirm that we were happy that there was no perceivable variation in sound quality over the Revision A version.

 All care should be taken not to damage the main board or any components, I found taking the unit apart nice and easy, the instructions felt clear and the demo photos really do help. I was a bit worried when removing the battery connection but again this was no problem and once done the board slid out easily. The jumpers are small and care is required but it is not Rocket Surgery, everything goes back together nice and easy and you are all done!

 A little bit of experimenting shows the volume is the only noticeable effect, and it is immediately noticeable. A clever little addition which helps this great little amp make even more sense to IEM owners as well as Full size headphone owners or, since it is so easily reversible, fans of both!


----------



## estreeter

Thanks for the update, Robin.


----------



## zer0hero

Hey there everyone.
  I'm contemplating between purchasing an iBasso D12 and this little amp here.
  Could anyone provide a comparison between the two amps?
   
  Thanks and Much Appreciated.
  Zer0


----------



## cn11

There simply aren't many owners of the uHA at this point..
   
  If you were looking for comparisons with the Arrow, I could help you with that, but that's about it unfortunately...


----------



## ungucpho

amp looks nice and compact


----------



## estreeter

Quote: 





zer0hero said:


> Hey there everyone.
> I'm contemplating between purchasing an iBasso D12 and this little amp here.
> Could anyone provide a comparison between the two amps?
> 
> ...


 

 I cant provide a comparison, but I believe it would be an excellent _combination _: use the D12 as DAC into the uHA-120. Justin's amp will flatter most sources, in my experience, and when HiFlight confirmed that the D12/P4 combination (the P4 is another brilliant portable amp worthy of your consideration )  was very good I immediately wanted to plug a D12 into the uHA-120. Like everything in audio, budget is always an issue and I am not currently prepared to throw money at a luxury item. Will let you know if that changes  
   
  (fwir, the one thing the D12 lacks is raw power - I believe the D4 was more powerful - and both the aforementioned amps have sheds of power)


----------



## cn11

Today I was using Headstage's DAC cable to my uHA from the work Mac.... just awesome sounding.


----------



## Anaxilus

Quote: 





cn11 said:


> Today I was using Headstage's DAC cable to my uHA from the work Mac.... just awesome sounding.


 


  Ahhh, so you like the DAC cable more than the UHA4 DAC it seems.


----------



## cn11

Unfortunately I haven't heard the UHA4... but it does sound like a pretty solid amp/DAC option. But as it so happens I was just perusing that comparison thread on the UHA4 vs. Arrow...


----------



## estreeter

The DAC in the uHA-4 is pedestrian - it does the job but its the weak side of the equation compared to the amp section.


----------



## Anaxilus

Oh woops, got my UHA's mixed up lol.


----------



## cn11

Yeah!! It's funny how similarly they're named.....  
	

	
	
		
		

		
		
	


	



   
  The Leckerton sounds like a solid little amp, and a front runner in today's portable selection though.


----------



## estreeter

I still think your average portable amp customer is looking for an equaliser rather than an amplifier per se, and it looks like Audinst got the memo:
   
  http://www.headfonia.com/korean-pocket-rocket-the-audinst-amp-hp/
   
  Plug your Turbines into that lot and prepare for a little ooga-chugga, people


----------



## vlach

Quote: 





cn11 said:


> Yeah!! It's funny how similarly they're named.....
> 
> 
> 
> ...


 

 Speaking of Leckerton, i just finished reading this entire thread and am surprised there are no comparisons with the UHA-6 which has similar specs/size/price...i guess no one has (yet) had the opportunity to test them side by side. Then again both products are relatively new and not very well known or as popular as other brands...maybe that will change in the future.


----------



## estreeter

Hmm, its like deja vu all over again ...
   
  @vlach, while the uHA-6 hasn't had many keystrokes here, the uHA-4 was a raging FOTM when it was released. I wrote an extensive comparative review between the 4 and the uHA-120 : if I had the money, I'd love to be able to compare the 6s with Justin's Class A portable, the AHA-160. Like many here, I would have been much happier if both companies had decided to use code names instead of model designations, but I guess 'LearJet' and 'Ballbreaker' might not have suited the designers' respective personalities.
   
  http://www.leckertonaudio.com/products/uha-6s/
   
  http://www.justaudio.co.uk/aha-120.html
   
  Ultimately, that's not an 'apples and apples' comparison - the iBasso D12 at 285 USD has SPDIF input to a very well regarded DAC section, but I suspect the Leckerton has the edge in terms of output power. When you find yourself considering D12 into P4 for portable use, it all gets a bit silly and I forced myself to stop buying portable kit. For now


----------



## vlach

Quote: 





estreeter said:


> Hmm, its like deja vu all over again ...
> 
> @vlach, while the uHA-6 hasn't had many keystrokes here, the uHA-4 was a raging FOTM when it was released. I wrote an extensive comparative review between the 4 and the uHA-120 : if I had the money, I'd love to be able to compare the 6s with Justin's Class A portable, the AHA-160. Like many here, I would have been much happier if both companies had decided to use code names instead of model designations, but I guess 'LearJet' and 'Ballbreaker' might not have suited the designers' respective personalities.
> 
> ...


 

 Yes, i read your review comparing the 4 with the uHA-120 (great review btw), however that doesn't tell me how the 6 stacks up against the uHA-120 specifically...anyway based on the limited reviews i read about the UHA-6, the overall consencus seemed very positive.
   
  In addition, Nick's design philosophy and dedication to his craft made me feel confident enough to place an order for the UHA-6. The other motivating factor is that if the 4 is that good, then i can't go wrong with the 6...plus i don't mind the exclusivity of a lesser known product


----------



## cn11

I'm sure it's a great choice... But, I think you should pick up the big baddie AHA-120 as well to do a comparison with the two amps. You know how HF works...


----------



## estreeter

Quote: 





> Originally Posted by *vlach* /img/forum/go_quote.gif
> 
> i don't mind the exclusivity of a lesser known product


 

 Excellent - are you familiar with the name 'Singlepower' ? No ? Then all this will be new to you !


----------



## vlach

Quote: 





estreeter said:


> Excellent - are you familiar with the name 'Singlepower' ? No ? Then all this will be new to you !


 

 I'm not familiar, i checked it out and it seems like a great product, however i'm reading that they are no longer in business and many people lost their money by ordering and never receiving their product?


----------



## estreeter

Quote: 





vlach said:


> I'm not familiar, i checked it out and it seems like a great product, however i'm reading that they are no longer in business and many people lost their money by ordering and never receiving their product?


 
   
  Sad but true - last I heard, the man behind the name behind the amps did a 'runner' and no-one has seen him since. Skylab heaped high praise on an earlier Singlepower amp, and opinion seems to be divided on the amps, but sadly the human being behind the designs just wasnt able to keep it together financially, for whatever reason. Its an interesting hobby, but certainly not the only domain where entrepreneurs come unstuck.


----------



## Michel01

Hi everyone,
   
  I'm a newcomer to this forum, although I've been reading it since a lot of time ago.
   
  My current portable rig consists of IPOD Classic 80Gb > HRT Istreamer (Battery powered) > Meier Corda Headsix. The headphones are Etymotic ER4P/S, Phonak Audeo PFE (grey filters) and
   
  AKG K500. I own a pair of AKG K701, but to drive them properly, I have a Heed Canamp (stationary use).
   
  So far, I am happy with the sound of the portable rig, but in search of improving the sound as a whole, my next goal is to get a new portable amp.
   
  I am wondering about the Justaudio uha-120 to drive the headphones (in-ear & AKG K500), but given the output voltage value of the istreamer (2,25 Volts RMS), I don't know if the Justaudio
   
  would be the correct choice (clipping & imbalance volume problems).
   
  I am currently using the headsix (hi gain mode) with the Etys & Phonaks at a volume around 9, hence my doubts regarding this matter.
   
  I have read about the 2Stepdance, but apart from the low battery duration, it seems to have issues regarding its digital volume (clicks & pops).
   
  I live in Spain, so I would really prefer to buy the amp in Europe (to avoid surprises with customs). The maximum price would be around 300 Euro, and both the 2Stepdance & Justaudio uha-120
   
  are inside this range of price. However I'm totally opened to another brands and models.
   
  I'm not a basshead, I rather prefer an accurate sound in all the spectrum.
   
  I strongly prefer quality more than quantity, and I would really appreciate your advices and comments before making a decision.


----------



## vlach

Quote: 





michel01 said:


> Hi everyone,
> 
> I'm a newcomer to this forum, although I've been reading it since a lot of time ago.
> 
> ...


 

 I am VERY happy with my Leckerton UHA-6 (with OPA209), which i feel is reasonably priced At $259US + shipping. Outstanding fit & finish, very clean & clear sounding with excellent dynamics. I really can't expect more for the price point.


----------



## estreeter

Quote: 





michel01 said:


> I am wondering about the Justaudio uha-120 to drive the headphones (in-ear & AKG K500), but given the output voltage value of the istreamer (2,25 Volts RMS), I don't know if the Justaudio would be the correct choice (clipping & imbalance volume problems).


 
   
  I doubt that you will have problems with clipping, and Justin revised the original design to deal with the channel imbalance at low volumes-  I believe there are several happy IEM users here to attest to that. Just be aware that you will be getting a powerful but relatively neutral-sounding amp : it will only be as good as your source and your phones. Most of what I have read about both versions of the Stepdance point to similarly neutral voicing, but I havent heard either of Jan's amps.
   
  I dont agree with everything Mike at Headfonia has to say on the gear I own, but he has the advantage of having access to many amps:
   
  http://www.headfonia.com/the-usual-suspects-12-portable-amps-compared/
   
  I'm sure that many of the Stepdance owners here would take umbrage with his summation of the Stepdance, but its bloody tough when few of us have access to every amp ever made. I also question the amount of effort Mike put into matching each amp with various sources/headphones - understandable when you consider the scope of that review, but hardly representative.


----------



## Angular Mo

@cn11
  those look to be some serious cables; which are they, who makes them, if I may ask ?  thank you.


----------



## estreeter

Quote: 





angular mo said:


> @cn11
> those look to be some serious cables; which are they, who makes them, if I may ask ?  thank you.


 


  cn11 or *vlach* ? If you are referring to the cable between the uHA-6 and iPod Touch on this page, thats an iBasso CB06:
   
  http://www.ibasso.com/en/products/show.asp?ID=54
   
  I have one, but I cant say that the sonics are any better with my sources/amps than a cheaper cable like this:
   
  http://www.belkin.com/IWCatProductPage.process?Product_Id=202363


----------



## estreeter

Quote: 





estreeter said:


> cn11 or *vlach* ? If you are referring to the cable between the uHA-6 and iPod Touch on this page, thats an iBasso CB06:
> 
> http://www.ibasso.com/en/products/show.asp?ID=54
> 
> ...


----------



## Angular Mo

My question was to cn11.... (thank you, though, for the reply!)
   
  On page 2 of this thread there is a nice sturdy looking set of cables, with what looks to be a woven fabric covering.


----------



## estreeter

OK - my mistake.


----------



## cn11

Quote: 





angular mo said:


> My question was to cn11.... (thank you, though, for the reply!)
> 
> On page 2 of this thread there is a nice sturdy looking set of cables, with what looks to be a woven fabric covering.


 


  Ah, hey there, sorry I missed your question for a bit....
   
  The line out cable is this one, purchased on Ebay from a maker in Hong Kong:
http://www.ebay.com/itm/Sony-Walkman-MP3-Line-Out-LOD-Cable-OFC-Silver-Plated-/280664514394?pt=Other_MP3_Player_Accessories&hash=item4158e89f5a
   
  The cable on my Ultrasones is a DIY cable by a member here who used to have a business doing that... but unfortunately he's not making cables for order anymore.


----------



## Angular Mo

To anyone,
  Which amp has more output power, the Just Audio uHA-120, or the iBasso Warbler P4 (when plugged into the wall, and running on battery power) ? 
   
  Admittedly, I am unsure how to interpret the specs;
   
http://www.ibasso.com/download/2010116142831.pdf
   
  I use DT770 Pro 80 headphones, and currently own the P4, and am considering an amp with more power and detailed resolution.
   
  thank you.
   
  Angular Mo


----------



## estreeter

Quote: 





angular mo said:


> To anyone,
> Which amp has more output power, the Just Audio uHA-120, or the iBasso Warbler P4 (when plugged into the wall, and running on battery power) ?
> 
> Admittedly, I am unsure how to interpret the specs;
> ...


 


  As one of the few here who has actually *owned both amps*, I know the answer to this question, but I'll leave it to cn11 to answer for you.


----------



## cn11

Quote: 





estreeter said:


> As one of the few here who has actually *owned both amps*, I know the answer to this question, but I'll leave it to cn11 to answer for you.


 


  Heh, unfortunately I don't own the P4 Warbler.... I'm sure the uHA-120 prevailed though.


----------



## estreeter

Let me just say this - I will buy another P4 before Jan 30, 2012.


----------



## Angular Mo

Quote: 





estreeter said:


> Let me just say this - I will buy another P4 before Jan 30, 2012.


 


  To estreeter,
  Please provide a comparison of the iBasso P4 with Just Audio's uHA-120.  I am also considering Just Audio's aHa-120.
   
  I just have not had much success trying to roll opamps in the P4, physically it is very difficult for me to do, maybe my fingers are too big to get into the small areas.  It tooke me hours to et back to the original setup.
   
  the P4 is not powerful enough for me, I want to use them to drive my home-based cans (770 Pro 80), not only my little cheap sansa earphones (until I find a good VFM earphone.)


----------



## estreeter

I'll make it easy for you - invest in the Matrix M-Stage or another home amp. Seriously - you just shouldnt be trying to drive big Beyers with small amps, no matter what you may have read about the Stepdance or whatever. The P4 is the most powerful portable amp I have owned, but the instant I plugged my AD900s into the E9, I knew I was dealing with a whole other universe - its about a lot more than volume.


----------



## Anaxilus

Quote: 





estreeter said:


> I'll make it easy for you - invest in the Matrix M-Stage or another home amp. Seriously - you just shouldnt be trying to drive big Beyers with small amps, no matter what you may have read about the Stepdance or whatever. The P4 is the most powerful portable amp I have owned, but the instant I plugged my AD900s into the E9, I knew I was dealing with a whole other universe - its about a lot more than volume.


 
   
  Spot on.  As the ladies say, size does matter.


----------



## estreeter

Hey, I didnt say I *like* accepting that reality, and I am still dead keen on finding a mains-powered amp with the same form factor as the Apex Butte.


----------



## Ultrainferno

Headfonia.com just put up their uha-120 review as well. they like it!


----------



## estreeter

Quote: 





ultrainferno said:


> Headfonia.com just put up their uha-120 review as well. they like it!


 


  I still want to write a comparison with the iBasso P4, but right now I'm eagerly awaiting the arrival of my EHP-02. So many amps, so few bucks.


----------



## cn11

Quote: 





ultrainferno said:


> Headfonia.com just put up their uha-120 review as well. they like it!


 


  Mine's been out on loan to multiple HF'ers for a good while, so I haven't gotten to listen to it for some time. But I think Mike has nailed just about everything on the amp in his review. 
   
  Glad to see that gem of an amp getting some in-depth attention.


----------



## estreeter

@cn11, I was less impressed by the fact that he tried to drive a HiFiMan ortho with Justin's amp - there is a hardcore of nutters on Head-Fi who seem grimly determined to drive the largest cans with the smallest amps, and this sort of thing plays straight into their hands.


----------



## cn11

Quote: 





estreeter said:


> @cn11, I was less impressed by the fact that he tried to drive a HiFiMan ortho with Justin's amp - there is a hardcore of nutters on Head-Fi who seem grimly determined to drive the largest cans with the smallest amps, and this sort of thing plays straight into their hands.


 


  Yeah, that does seem to be asking a bit too much of a portable.... I don't doubt it has drive a plenty, since it is nowhere near running out of steam with my Pro 900's, but from what I've read of the HiFiMan headphones it may a bit of a reach.


----------



## Sorensiim

Curse you all, especially Estreeter for his most excellent review.
   
  I've just ordered a uHA-120, less than 48 hours after I got my Fiio E11.


----------



## Ultrainferno

Quote: 





sorensiim said:


> Curse you all, especially Estreeter for his most excellent review.
> 
> I've just ordered a uHA-120, less than 48 hours after I got my Fiio E11.


 


  Believe me they can't compete. You'll love the µha


----------



## Sorensiim

Quote: 





ultrainferno said:


> Believe me they can't compete. You'll love the µha


 


  I got the E11 only to see if I would even use a portable amp. Took me exactly one day at work with my J3 hooked up to the E11, powering my Pro 900 to decide that A) portable amps kick ass and B) I need something better than the Fiio.


----------



## estreeter

Quote: 





sorensiim said:


> Curse you all, especially Estreeter for his most excellent review.
> 
> I've just ordered a uHA-120, less than 48 hours after I got my Fiio E11.


 


  If its any consolation, I curse many here and elsewhere for building the never-ending consumerism that is Head-Fi. We all know the answer - find another hobby.


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## estreeter

Quote: 





ultrainferno said:


> Believe me they can't compete. You'll love the µha


 


  I dont think either of us can make that call on behalf of someone else - not unless you know his gear/tastes extremely well. Even at the upper end of this hobby, there are folk who disagree wildly on a given component - check out some of the meet impressions on the Stax SR-009 and the Senn HD800, ostensibly two of the best headphones in the world. There are even some people here who refuse to consider a tube amp, *any* tube amp, on the basis that iit will distort their music. Its a broad church.


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## Ultrainferno

I agree. Tastes are different, one of my friends prefers the E11 over the µha, yet qualitywise the µha is the better of the 2


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## Sorensiim

Quote: 





ultrainferno said:


> I agree. Tastes are different, one of my friends prefers the E11 over the µha, yet qualitywise the µha is the better of the 2


 


  I have the E11 and the RSA P51 on my desk right now - The P51 is clearly the more refined of the two, but the E11 has so much more power. If the uHA-120 gives me the resolution of the P51 with the power of the E11... Oh boy.


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## estreeter

Quote: 





sorensiim said:


> I have the E11 and the RSA P51 on my desk right now - The P51 is clearly the more refined of the two, but the E11 has so much more power. If the uHA-120 gives me the resolution of the P51 with the power of the E11... Oh boy.


 

 That's all good, but your total outlay for the amp you dream of will be something approaching a thousand dollars. I'm beginning to see Uncle Erik's point.


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## Sorensiim

Quote: 





estreeter said:


> That's all good, but your total outlay for the amp you dream of will be something approaching a thousand dollars. I'm beginning to see Uncle Erik's point.


 


  I'm in pursuit of that magical point where everything sounds good_ to me_. I hope the µHA-120 will be the amp for me. The P51 is a loaner and the E11 is sold - I don't keep stuff I don't use


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## dookie182

hi guys
  I've been keeping an eye on this portable amp for quite some time now and I was wondering how it was performing PRAT and pace wise.
  Having read both reviews from the AHA and uha on headphonia, it seems that the prat factor is here but mike told me that "full sounding and fast pace does not mix that well, so according to him, the AHA is more on the slow pace side of headamp.
  listening to lots of fast and energetic musics (rock, ska punk, harcode) I was wondering how does the uha performes conpared to his brother the AHA?
  beeing a new dad, most of my day is busy between my family and my work, so the only time left is when I go to bed, so I'm interested in the compromise of this high quality, usb or batterie powered portable amp,
  any advise is welcome
  kindest regard


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## Sorensiim

My uHA-120 should be arriving today and I'll be sure to give it a spin with RATM, Disturbed, Rammstein, Deadmau5, Combichrist and Prodigy. My Ultrasone Pro 900 are just about the fastes, punchiest things I've ever tried and I know they kan keep up with the music - Let's see how the uHA-120 fares with them.


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## estreeter

Just don't expect miracles in the first 10--20 hours. regardless of whether or not you believe in burn-in. This amp is closer to neutral than some might be ready for - I still have music which is happier with the uHA-4s  less revealing treatment.


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## dookie182

sorensiim,
  thanks for the info, I'm looking forward to your impressions.
   
  estreeter 
  thanks a lot your your participation on all this thread, it's really appriciated
   
  by the way,
  any advise for a closed headphone (I'm mostly listening to music in bed, so my dear half will appriciate the closed design) that will do nice with fast paced music, have a good bass anchor but a "preserved mids" in the same time.
  I'm looking toward the denon AH-D2000, but other advises are welcome 
   
  kindest regards


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## Sorensiim

Mine came today and it's bloody awesome... So much more refined than the E11 and at the same time so much more natural sounding. Love it so far!
   

   

   

   

   
  And it certainly packs a punch! Bass goes deeper than it does with the E11 or the amp in my Yulong D100, but it always remains very controlled. Drums have an _awesome_ kick from this little thing!


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## Ultrainferno

Glad you're happy!
  I've compared it with the AHA-120 the last few days and they have completely different sound signatures


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## Sorensiim

Quote: 





ultrainferno said:


> Glad you're happy!
> I've compared it with the AHA-120 the last few days and they have completely different sound signatures


 


  You can't just post stuff like that without elaborating it! Tell me everything!


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## Sorensiim

I cannot believe that this little thing packs such a punch, yet manages to sound so clean. It's a great addition to my Cowon player while on the go or at work and even better at home when hooked up to my fullsize DAC. (Yulong D100). 
   
  It really adds some impressive depth to the bass, but does so without blurring the rest of the spectrum. Voices sound so natural and no matter what I throw at it, it just sounds so effortless. Rammstein with the uHA-120 and Ultrasone Pro 900 is nothing short of amazing. Punchy and fast, yet very detailed and natural sounding. It has a very slight warmth to it's sound, but doesn't come off as colored anyway like most tube amps I've heard. I am madly impressed by this little amp!


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## Ultrainferno

Quote: 





sorensiim said:


> I cannot believe that this little thing packs such a punch, yet manages to sound so clean. It's a great addition to my Cowon player while on the go or at work and even better at home when hooked up to my fullsize DAC. (Yulong D100).
> 
> It really adds some impressive depth to the bass, but does so without blurring the rest of the spectrum. Voices sound so natural and no matter what I throw at it, it just sounds so effortless. Rammstein with the uHA-120 and Ultrasone Pro 900 is nothing short of amazing. Punchy and fast, yet very detailed and natural sounding. It has a very slight warmth to it's sound, but doesn't come off as colored anyway like most tube amps I've heard. I am madly impressed by this little amp!


 


  I told you


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## FragmentedGod

I have a FiiO E7 that I like, but I just don't feel is up to scratch, so I've been looking for a new headphone amp.  I've read a lot of reviews and ended up closely following what people have been saying about the Just Audio amps.  I've been in touch with Justin, who has been extremely helpful, and tomorrow I should be able to order a Vishay pot upgraded version of the amp!  Really excited, as I haven't seen a bad word said about the amps.
   
  I've got a pair of Beyer DT1350s that I think will really benefit from the improved amp.  I love the 'phones but I think I will always wish they have more bass than they do .
   
  Sorensiim, you're obviously very happy with these paired with the Ultrasone Pro 900s!  I've been looking at getting a pair of those but worry that they just won't be portable enough.  I used to have a pair of Denon 1001s and no matter how careful I was they eventually ended up breaking because there was no good way to store them.  I understand the Pro 900s come with a case but they still just look like they're SO much bigger than the DT 1350s.  You use these on the road or are they a more stay-at-home phone for you?
   
  I will definitely put up my impressions when I've had some time to let the amp burn in a bit and listen to some different stuff through it.  I won't have the amp til early next week though, so will be a little while.


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## Sorensiim

Quote: 





fragmentedgod said:


> I have a FiiO E7 that I like, but I just don't feel is up to scratch, so I've been looking for a new headphone amp.  I've read a lot of reviews and ended up closely following what people have been saying about the Just Audio amps.  I've been in touch with Justin, who has been extremely helpful, and tomorrow I should be able to order a Vishay pot upgraded version of the amp!  Really excited, as I haven't seen a bad word said about the amps.
> 
> I've got a pair of Beyer DT1350s that I think will really benefit from the improved amp.  I love the 'phones but I think I will always wish they have more bass than they do .
> 
> ...


 

 I used to have the HD25-1 II which is about the same size as the DT 1350 and the Pro 900 are literally twice as big. They're big and comfortable and while I love wearing them at the office, I can't really use them on the bus or anything like that - They're so big that the collar of my coat prevents me from turning my head when I wear them 
   
  I have no qualms bringing them with me though. Yes, they're plastic, but they're tough as hell. When was the last time you broke a Lego brick?


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## FragmentedGod

Quote: 





sorensiim said:


> I used to have the HD25-1 II which is about the same size as the DT 1350 and the Pro 900 are literally twice as big. They're big and comfortable and while I love wearing them at the office, I can't really use them on the bus or anything like that - They're so big that the collar of my coat prevents me from turning my head when I wear them
> 
> I have no qualms bringing them with me though. Yes, they're plastic, but they're tough as hell. When was the last time you broke a Lego brick?


 


  Haha!  Can't even turn your head... yeah I think that's too big to be portable .  I think that whenever I see those enormouse Beats headphones.  I think in time I'll invest in a pair of the Ultrasone but not for out and about.  As long as they have a case I don't see them ever getting damaged, just really need something more portable than that for travelling.
   
  I've just ordered my uHA-120!  Should have it in a couple of days.  Really excited heh.  And both HiFi Headphones and Justin from Just Audio are a pleasure to deal with.


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## estreeter

Quote: 





> Originally Posted by *FragmentedGod* /img/forum/go_quote.gif
> 
> Really excited, as I haven't seen a bad word said about the amps.


 
   
  Clearly, you didn't read the reports from disgruntled IEM users who found the default gain on the initial batch of uHA-120s to be too high, rendering the amp unusable even at 9am for some folk. Justin, to his credit, responded quickly and the 'Rev 2' has lower gain settings.
   
  I also made the point in my review that this wont be the 'right' amp for everyone, and that those wanting a warmer, more forgiving presentation may be better served elsewhere. The 120 tends to tell it like it is - for all the buzzword-compliance on HF, I dont know how many are genuinely prepared for that.


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## Anaxilus

Quote: 





estreeter said:


> I also made the point in my review that this wont be the 'right' amp for everyone, and that those wanting a warmer, more forgiving presentation may be better served elsewhere. The 120 tends to tell it like it is - for all the buzzword-compliance on HF, I dont know how many are genuinely prepared for that.


 

 I think our respective points of reference might be different but I don't consider the uHA-120 the most resolving, transparent and accurate portable amp out there.  My Leckerton is on another level by comparison.  I do consider the uHA-120 a warmer, more fun sounding amp with pretty good technical performance.  It is enjoyable.


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## Ultrainferno

Quote: 





anaxilus said:


> I do consider the uHA-120 a warmer, more fun sounding amp with pretty good technical performance.  It is enjoyable.


 

 I agree to that. The AHA on the other hand is less warm but more detailed, bigger soundstage, ...


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## FragmentedGod

Quote: 





estreeter said:


> Clearly, you didn't read the reports from disgruntled IEM users who found the default gain on the initial batch of uHA-120s to be too high, rendering the amp unusable even at 9am for some folk. Justin, to his credit, responded quickly and the 'Rev 2' has lower gain settings.
> 
> I also made the point in my review that this wont be the 'right' amp for everyone, and that those wanting a warmer, more forgiving presentation may be better served elsewhere. The 120 tends to tell it like it is - for all the buzzword-compliance on HF, I dont know how many are genuinely prepared for that.


 


  I have read those, however that isn't a judgement on the quality, so I didn't factor that in - but fair play.  I'm going to be using the amp with 80ohm headphones, and the new revisions of the amp also come with a jumper to adjust the gain so they can be used with lower gain IEMs.  So if I pick up a pair of JH-16's then I can try it out .
   
  Mine just arrived and so far I'm loving it.  My headphones are very precise (Beyer DT1350s) so this is a really good match.  The amp has a lot of bass and is much warmer, so it pairs very well with the headphones.  The soundstage is way bigger than on my FiiO E7 (no surprise there!) and while it doesn't sound quite as clean, partly because the bass is so much more pronounced, I really prefer the sound.  The music that I love through the E7 I'm not as impressed as I thought I would be with the uHA-120, but everything else sounds so much better.  Really happy with it and I'm sure it'll get better once it's worn in a bit!


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## lee730

Quote: 





anaxilus said:


> I think our respective points of reference might be different but I don't consider the uHA-120 the most resolving, transparent and accurate portable amp out there.  My Leckerton is on another level by comparison.  I do consider the uHA-120 a warmer, more fun sounding amp with pretty good technical performance.  It is enjoyable.


 


   
  Lol Anaxilux you are not helping. I was already debating between the UHA120 and the UHA 6. I think you've swayed me back to the dark side (UHA6). I figur I'll have more power with the 6 and I can swap out OP Amps for versatility. Thanks once again.


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## FragmentedGod

I've had the uHA-120 for a while now.  It pairs extremely well with the DT1350s.  The soundstage is much bigger, separation of instruments is excellent and the mids and especially the bass get a big boost.  Unfortunately, the amp has the opposite effect on the treble.  Everything still sounds clear but it loses the sparkle that the Beyers have normally, which is one of my favourite things about them.  I am really happy with the amp and use it all the time, but the music that I love listening to when using the headphones with a FiiO E7 is the stuff that this amp isn't as good at. 
   
  For most music it's excellent, but if you like your treble and listen to anything like Rodriguo y Gabriela (11:11 especially) - very clean, sharp guitar sounds and no need for extra bass - then you're better off with something else.  I'm going to keep on happily using it but will eventually upgrade to something that matches its soundstage and bass but without losing that focus on the high end.  I expect I'll have to pay a lot more when that time comes though!


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## cn11

Hmmmm, bit of a strange observation about the treble. Besides the bass, absolute control across the board, and dynamics... treble is one area where I feel it excels the most. I've heard a colleague's F7, and the uHA is on a totally different level when it comes to treble extension, clarity, and detail. It's even noticeably better than my Arrow 3G in that regard. Maybe there's some pairing weirdness with the DT1350 (I only had them briefly, and not when I got the uHA).


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## estreeter

I guess we all hear different aspects of the same amp's performance, and I had no idea to what extent that is being determined by our individual sources. phones and musical preferences. I'm in the early stages of burning in (ears or amp, something is burning in ..) a new amp that I wont name, and I'm convinced that it is better with electronica than with the bulk of my music (rock), but I know from past experience that such early impressions are subject to change. I didnt think a whole lot of iBasso's P4 when I first cranked it up, but by the 100-hour mark it was a different story - fortunately, I've spent long enough with the uHA-120 to just turn it on and forget all about the gear.


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## Kunlun

anaxilus said:


> I think our respective points of reference might be different but I don't consider the uHA-120 the most resolving, transparent and accurate portable amp out there.  My Leckerton is on another level by comparison.  I do consider the uHA-120 a warmer, more fun sounding amp with pretty good technical performance.  It is enjoyable.





This is exactly how I heard the uha-120.


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## lee730

Quote: 





kunlun said:


> This is exactly how I heard the uha-120.


 


  And its gonna save my pocket money . Guess Leckerton will have a repeat customer. I eventually will pick up the UHA6S with a handful of OP AMps to roll. Wondering though what are the best ones. I want the best of all worlds from the most neutral to sultry mid centric.


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## melkenshawn

Anyone knows if the uHA 120 pairs well with jh13?


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## xallarap

Sorry for reviving this thread but has anyone tried the Just Audio uHa-120 with the HD25? Thanks!


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## dryvadeum

Is the AHA 120 a big step - worth the money - from the UHA 120?


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## dryvadeum

dryvadeum said:


> Is the AHA 120 a big step - worth the money - from the UHA 120?




Anyone?


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## Ultrainferno

It's a different sound. The uha is the fun big bass one, the aha is the more neutral one. I think Headfonia had a review on them


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## dryvadeum

Quote: 





ultrainferno said:


> It's a different sound. The uha is the fun big bass one, the aha is the more neutral one. I think Headfonia had a review on them


 
  Which one is more refined though?


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## Ultrainferno

The AHA, no doubt about that. I have sold both a while ago but my fav for on the go was the µha, never got to enjoy the aha as much as the µha


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## dryvadeum

Quote: 





ultrainferno said:


> The AHA, no doubt about that. I have sold both a while ago but my fav for on the go was the µha, never got to enjoy the aha as much as the µha


 
  Do you think the uha would pair well with the LCD 2's?


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## Ultrainferno

Definitely not, these are no amps for planars imo


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## Dafo

Just to add a little info on this fine amp: The uha120 pairs well with the k701(bassport modded), powerful and smooth, everything is just right.
It's the second time I own it and the right words are indeed "enjoyable" and "just turn it on and forget all about the gear", it's as simple as that with this amp, and that is very easy to recommend


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## zloxious

So..the brand is dead I suppose ?? uha120 is nowhere to be found.. amazon or any online shop i knew.. their website dont works too..


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## waxdoctor

does anyone know which replacement battery to get for a uha-120 or uha-120ds? thanks!


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