Leckerton Audio UHA-6S.MKII – Sniff Of Brilliance

Performance

As far as I can tell, the UHA-6S.MKII’s DAC is best used through its USB input, where dynamic range and signal to noise ratios are highest. But its amp is best utilised when fed a high-quality upstream analogue signal.

It keeps up generally well with the MS-AK100 and the AK Jr, both phenomenal DAPs. And, by and large, it is stable when driving high-current loads. It isn’t nearly as stable as ALO’s most recent Rx, but it outputs less hiss, and thanks to a laid back gain, balances channels sooner. If you’re keen to know, the Vorzüge PURE II hisses even less.

That said, completely balancing channels requires a mean volume of around 80-85dB. Mine balances in low gain at -24 dB at maximum sensitivity from the Lynx HILO, which is about 10dB higher than I prefer to listen. That said, my ears don’t detect the channel imbalance at any comfortable listening level.

I hope my maths aren’t too off: I have about 20º of headroom in the volume pot with which to raise the volume after nailing L/R channel balance. Impressive. Further, under load, it shows less than 1% deviation against loaded controls in noise level and dynamic range. It maintains a mean stereo crosstalk of over 90dB, actually nosing past 95dB whilst driving the Earsonics SM2 at high volume levels.

At normal listening levels, it is perfectly suitable with sensitive earphones and headphones. When volume is pushed far, it shows several deficiencies, namely ramping THD and IMD, the latter of which is both measurable and audible in a benchmark test setup. Naturally, volumes at which a UHA/SM2 combo fall apart are at mean decibel levels of around 110dB – at which no one should ever listen to music. At mean volume levels of 105dB (please don’t listen this high), the UHA-6S.MKII is perfectly stable.

When feeding from the iPhone’s USB, I am comfortable listening through the 600Ω DT880 in low gain at near full volume. When siphoning analogue from the AK Jr, it is plenty loud for me in low gain at about 11 o’clock (the pot goes to about 5 o’clock). A turn of the volume pot to full in HG makes my DT880/600 distort like mad. Not enough current at that volume. It stabilises again at 2 o’clock, thirty minutes. And while I would never listen to that level, Chase Emory might. Just. If you’re not Chase (and even if you are), please, take care.

The UHA-6S.MKII is a great companion to ultra-high end players such as the AK380 and 240, whose outputs are troubled by zombie-like IMD and THD. And, while this UHA isn’t perfect, it is more capable of driving stable signals to more wildly swinging loads than is the AK380.

Most of that is down to its incredible amp stage. Its DAC is no mean thing. But the UHA-6S.MKII comes into its own when fed analogue. It isn’t able to replicate the MS-AK100’s pristine THD swept frequencies, but in most other metrics, it cleaves. And its amp is more powerful.

While it’s not perfect, it is one of the stablest do-all amps out there.

Sound

Despite its pretty face, and functional form, the Leckerton UHA-6S.MKII is about as geek as it gets in the portable world. Socketed op-amps allow you to customise your sound. Want more, or less distortion? There are op-amps galore ready to colour your music.

The op-amp set in the review unit is: AD8610. It is very stable across many loads. Because I’m not a roller, I haven’t tried it with other op-amps. I’m sure it is a great platform for it.

Stock, the UHA-6S.MKII is neutral with a slight detail preference to the mid range. Its sound stage is large, but not wide. It takes up a 3D footprint both high and deep. It is mildly wide, and organic.

It nails about as much detail in every frequency, meaning that music with a huge dynamic range will sound detailed, clear, and well spaced. But there’s a bit of warmth there, which gets me, a whisky-nosed bloke of 36, in the mood for another sniff.

Meh

If you’re into skinny jeans and walking around town, the Leckerton may pose problems. Sure, you’ll be able to shoehorn it in next to your funny bone, but climbing the stairs, sitting for lunch, and especially when leaning at the bar of an out-of-the-way coffee may roll the volume pot. Not too much, but it probably will roll. It’s not too easy to move, but it can catch on clothing. Especially on skinny jeans. Finally, this amp really picks up finger prints. And since the Lecker isn’t lackered up, wiping those prints requires alcohol. I’m down.

End words

For its price you simply can’t go wrong with the UHA-6S.MKII, though if you rely primarily on digital input, there are be better options, definitive or not. Regardless, there are few DAC/amps that provide as much functionality and performance at this price range.

Great job Nick.

4.2/5 - (15 votes)
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Back before he became the main photographer for bunches of audio magazines and stuff, Nathan was fiddling with pretty cool audio gear all day long at TouchMyApps. He loves Depeche Mode, trance, colonial hip-hop, and raisins. Sometimes, he gets to listening. Sometimes, he gets to shooting. Usually he's got a smile on his face. Always, he's got a whisky in his prehensile grip.

21 Comments

  • Reply December 3, 2015

    Barun C

    Nice review. On a different note, portable amps were slowly fading away from the memory until the mojo came along. But for me the QP1R is the best sounding portable amp out there, even though it is a DAP. Hope you review the QP1R someday Nathan, even though it comes from a Chinese Manufacturer.

    • Reply December 3, 2015

      ohm image

      I’m waiting to get in the queue. I used it very briefly at Fujiya headphone festival: I agree on all fronts. Beautifully made, beautiful sounding and easy (the scroll wheel has issues) to use.

  • Reply December 3, 2015

    Raison

    I have a Sony NW-ZX100, beautiful sound, but a lackluster amp. Was thinking of getting a amp for use with customs like the fitear 334. I was always thinking of getting the alo rx till I saw this review, any suggestions on a amp I should pick?

    • Reply December 4, 2015

      ohm image

      Well, if all you want is an amp, and you have the dosh, the Rx is more stable for the FitEar at all volumes. The 6S.MKII is not far behind, and it hisses less. But it has a few questionable parts regarding its performance with as wide range of headphones. That said, the Rx really has only the power for IEMs and really sensitive headphones. My only beef with the Rx is that it hisses a bit.

      The review here is a good place to start. Then I’ve written at length about the Rx’s performance at ohm: http://ohm-image.net/data/audio/rmaa-alo-audio-rx-24-bit

  • Reply December 9, 2015

    Chris

    Another nice review! I had some experience with UHA-4 a long time ago.

    • Reply December 10, 2015

      ohm image

      They are phenomenal. BTW, I’ll be posting measurements of its output, both loaded and unloaded soon, fed by a Chord MOJO (my newest review). It holds up very well in metrics such as dynamic range, but falls quickly in noise. In many metrics it is neck and neck with my favourite portable amp, the Vorzüge PURE II, but overall the PURE II is stabler.

      http://www.headfonia.com/vorzuge-pure-ii-single-ended-perfected/

      • Reply December 10, 2015

        Chris

        I am quite interested in Mojo. However still cant get rid of the idea of getting a cowon p1 or onkyo dp-x1.

        • Reply December 10, 2015

          ohm image

          Mojo in combination with a smartphone gives far better single-ended performance, and has a more powerful output:

          Mojo RMAA: RMAA: http://ohm-image.net/data/audio/rmaa-chord-mojo-24-bit

          DP-X1 RMAA: http://ohm-image.net/data/audio/rmaa-onkyo-dp-x1-24-bit

          From what I understand, Cowon’s P1 is also very good. As you can see, the DP-X1 performs nearly flawlessly from balanced, but its single ended output isn’t in the same league. The UHA-6S.MKII better the DP-X1’s single ended output in most metrics when fed a good USB or other signal, so for 279$ USD, you get to keep the benefits of your iPod touch or iPhone: gapless playback, good battery life, good hand-holdability, and better interface. But you have to use two boxes.

          • Reply December 10, 2015

            Chris

            I actually got rid of headphones that are difficult to drive and keep things simple. I now only have ex800st, tf10, hd25 i-ii for on-the-go purpose. Still a lot of stuff but I suppose I don’t need any expensive amp. Just the right one.

            • Reply December 10, 2015

              ohm image

              Well, the UHA-6S.MKII punches all those bullet points.

              • Reply December 10, 2015

                Chris

                True. I guess I just need to return to the turmoil. Thanks for the info.

  • Reply December 12, 2015

    Miko Belardo

    Great review, Nathan!

    However, I feel the need to point out that on the Leckerton Audio website, the UHA-6S.MKII has been marked “Temporarily sold out” for months and months now. I was very keen to get myself one of these based on the positive reviews but it has not become available to this day. I emailed the company regarding availability, but the only reply I got was that the website would be updated when it becomes avaialble. That was way back August 19 of this year.

    • Reply December 14, 2015

      ohm image

      I hope so, too. I didn’t quite notice that when I published the review. I got the amp early this year, and it was still available. My review was late. Let’s hope it comes back.

    • Reply December 17, 2015

      Chris

      I emailed him earlier and he said it will be in stock in January.

      • Reply December 17, 2015

        Miko Belardo

        Nice of you do so, Chris. Thanks for the heads up!

        • Reply December 18, 2015

          Chris

          You are welcome.

      • Reply December 18, 2015

        Headfonia_L.

        Thanks Man!

      • Reply December 23, 2015

        ohm image

        Chris, you’re a gentleman and a scholar.

        • Reply December 23, 2015

          Chris

          You are welcome.

  • Reply January 19, 2016

    Isaiah Mackler

    I’ve currently got only a X3ii. I think the Leckerton UHA-6s Mkii (which is back in stock) has the same dac as the X3ii. From reading reviews (though no comparisons), the UHA-6S Mkii has a better amp section than the X3ii (which lots of people say is its weak point) while the line out of the X3ii gets a lot of reviews for being a good source (while the UHA6S Mkii does not). That being said… should I stick with my X3ii, get a UHA6S Mkii instead, or get two unitls like the X3ii w/ a portable amp (or buy the Mkii to use as an amp) or get an external Dac and use MKii as the amp? I really don’t need a dap; I can’t remember the last time I listened apart from my laptop, and I’m sensitive to hiss- using exclusively with iems. Thanks a ton!

  • Reply October 7, 2016

    reagan

    hi headfonia, i just looked at their ordering site but it stated that uha-6s mkii is out of stock now, any idea when it will be back in stock?

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