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Just Audio AHA-120

Posted

Pros: Sound & build quality

Cons: Expensive but other than that, none

First of all let me say that I acknowedge that this is an expensive amplifier. Not extravagent in the big scheme of things, particularly if you consider some headphones but as a portable amp it is significantly more expensive than others on the market and for this reason it needs to justify itself (no pun intended).

 

I have stalked this amp for a while after seeing positive reviews around the place. I have just sold a Graham Slee Voyager and have had a Little Dot Mk1+ as my day to day portable amp up to now so I had the funds finally available to purchase and treat myself.

 

I purchased from one of the two retailers available in the UK and the parcel turned up the following day. Impressive. The packaging is quite basic with just the amp, some sticky feet and tools to open and adjust the amp itself. There was no instruction manual available but I can't imagine it would say much anyway as it is all very intuitive.

 

I have not had chance to listen to a great deal of music as yet so this is very much a first impressions review. I will add to it later on as I get familiar with it and what it is doing to my music.

 

One thing I find having read a number of reviews on here is that there is often a lack of context to reviews. Hifi is all about the music, not the kit or the preferences of the reviewer, but the music that is being listened to. For a reviewer to say that such and such an amplifier has a "solid bass" is not very helpful unless you know what they are listening to. If they love drum and bass it will help understand what sort of bass is being heard but if they are into acoustic folk music then maybe something else is being heard. Obviously we all have our tastes and one mans good sound is anothers bad. But I will try and relate what I am hearing and how it impacts the music I am listening to. If others find this helpful then great but please treat this as subjective, as all reviews inevitably are. As background I have used Beyerdynamic T50p headphones and Colorfly C3, RoCoo P and Cowon X7 players with this amp to date.

 

OK, so having got that off my chest what is the Just Audio AHA-120 like?

 

My first listening was to the Orb's debut album, all three disks of it. For this the amp gave a lovely clean presentation and the vocals were more clearly heard than I have ever heard them before. The speaking part of Little Fluffy Clouds was rendered beautifully with every intake of breath and nuance of the voice given space in front of the music. Minnie Ripperton was also given plenty of room.

 

Switching to Amiina's Kurr album I deliberately chose this because the instrumentation is sparse, haunting and at its best, spine tingling. The opening bars of the first track can leave me spell bound. Whilst I did not get the hairs on my neck standing up with the Just Audio it was appreciably more realistic than I have heard from any other portable equipment. My home set up can really do this album justice but the portable one is still a little way short in giving me the same experience. The voices and strings were both very realistic and seemed to eminate from a completely silent background. Iceland has a disproportiote amount of talent at the moment and this album was conveyed with as much emphasis on the space around the musicians as the music itself. There was nothing closed in or claustrophobic about it, something I have felt with my other amps in the past.

 

I also listened to Jean Michel Jarre's Oxygene. This too is a reference album for me and the way the synthesiser bounces around between the speakers at various points can make all the difference to the experience. I have to be honest and say that I was not captivated. The music did not grab my attention I was expecting it to. This unit does need time to open up like a flower before the morning sun (sorry - don't know what came over me there).

 

I have now had chance to listen to this with a bigger range of music and it is growing on me. I listened to Simon and Garfunkel and the simple arrangements and crisp vocals really stood out. Similarly the Beach Boys Friends album now had more emphasis on the glockenspiel than I have noticed before and you could really follow the individual voices on the harmonies. Even the Beatles benefitted with Ringo's drumming clearer and more separate than I have heard from portable equipment before. Also the musicians seemed to be better placed around my head with space between drummer and guitarist and vocalist etc. Kraftwerk's Autobahn sounded deeper and more foreboding in places than I have heard before.

 

I think what I am finding is that there is a commendable lack of fuss with this amplifier. You don't get an immediate rush of sparkle or rumble of bass, what you do get is clean, clear interpretation of the music you are playing. It does not flatter to deceive but just gets on with the job of replaying music accurately and cleanly. I am using the world clean a lot and I think this is it. There is no muddying of instruments and no fuzziness at the extremes. This might imply a dry, lean presentation but it isn't. It is just a lot more space than I am used to. Also any background hiss that I previously noticed with the RoCoo had disappeared. Silences are definitely silent with this amp.

 

I took this amp to the London Meet in April and had chance to compare my set up to some others. This reinforced to me just how good this amp is. Sure I could still get blown away by listening to kit two or three times as much again but it was not two or three times better. It even improved a Hifiman 801 I was fortunate enough to listen to. I am now seriously in love with the Just Audio AHA-120. Is it still relatively expensive? Sure. Is it worth the outlay? Yes.

 

In summary: This is a well made amplifier that is bigger than your normal portable amplifier but one that is ideal if you plan to be relatively sedentary with it. It is not really pocketable unless you have big pockets (and deep given the price) and recent experience has shown that it is not ideal to have when travelling on the train or underground, it's sheer bulk being inconvenient. Musically I have been impressed with and it is continuing to get better as hours progress. It is better than any portable amp I have heard. The instrumentation is clean and vocals in particular get given an excellent delivery in the range of music I have listened to. I am conscious that it still has to earn its price tag and I do have greater expectations of this amp than I do my Little Dot but so far I think it is worth the extra outlay, provided you do not plan to take it with you on the tube every day!

PS: I can also commend Justin's support to his products. I had a minor issue with the volume control and Justin sorted it out quickly and painlessly. Thank you Justin.

Posted

Pros: Wide Sound Stage, Detailed Reproduction, Powerful

Cons: The gain setting needing the case opened. Very unforgiving of sub-standard input.

The physical aesthetics of this little powerhouse are greatly undervalued. Until I had it in my hand I thought of it as quirky and eccentric looking. How wrong I was. This is a thing of real beauty, in the visual aesthetic, the quality aesthetic, and in its power and sound quality.

 

Turning on the volume pot exudes quality. Very smooth. No mechanical or digital click but a soft feeling of confirming that it’s on. Very difficult to describe. It’s all a build of the highest quality.

 

Wide sound stage, detailed flowing reproduction with a powerful and full style. I use the Model with a Zero Gain option but I understand (Headphonics Dec,23 2012) that this can drive Planers with ease (presumably on its high gain setting).

 

Downside? Main one that you have to open up the casing (‘tools’ provided) to change the gain. Mind you this gives you the opportunity to admire the electronics. Very unforgiving of sub-standard input.

Just Audio AHA-120
Description:

The AHA-120 is a transportable pure class A headphone amplifier, suited to driving most full size headphones and IEMs. Intended for the most discerning listener, the AHA-120 incorporates a discrete class A output stage, ensuring zero crossover distortion; Whilst the front panel features an additional high quality NKK rotary selector, allowing the end user to tailor the amount of class A bias to suit a given pair of headphones. For instance, with 600 ohm headphones the least amount of bias can be used, therefore operation time is extended considerably. Of course, the chosen internal rechargeable battery not only has excellent characteristics for audio, but is big in capacity, enabling up to 18 hours of operation time when using the maximum class A bias setting. Like the µHA-120, micro jumpers are fitted to the PCB as standard, so that the AHA-120 can be configured to either 6dB (x2) or 12dB (x4) maximum gain to suit headphones and IEMs. In addition, the same careful attention has been placed on the layout and choice of the electronic components, with particular emphasis on ensuring the very best audio quality and excellent immunity from unwanted noise sources. As standard the stereo analog volume potentiometer is a specially in-house graded and modified part. This process involves only selecting parts with the best channel balance and then applying our ‘White Velvet’ modification, creating a near perfect passive analog volume control with a premium smooth and consistently weighted rotary movement.

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