I generally like to be one of the first people to review a product. If something has been out for a while, and already reviewed multiple times, I usually don’t bother. If I like something I’ll casually comment on it or even recommend it, but I generally won’t do a formal review if I feel enough has been said already. The only exception I can think of is if I try something and find my opinion differs by a large margin compared to the existing reviews.
That being said, I find myself reviewing a product that has been out for a while, and already has multiple reviews that are fairly well done. I also happen to agree with the prior reviews. The reason why I’m breaking my own rule here is that this item seems to have been severely overlooked around here. Sometimes a product is released and becomes a “flavor of the month”, for better or for worse. Other times a product is largely ignored despite being an excellent performer by all accounts. The Leckerton UHA-6S seems to belong to the latter category, and I’m not sure why.
Nick at Leckerton graciously offered to loan me a review sample. He’s a great person to deal with, and I am confident that real customers would be very well taken care of. Unfortunately I got sick shortly after receiving the UHA-6S, and was too stuffed up to do any listening for several weeks. Nick was very accommodating and allowed me to keep the unit for an extra few weeks, which was very kind of him.
Leckerton is a small company based near Chicago Illinois. They had a minor hit with their previous product, the now discontinued UHA-3 from 2007, and have followed up with the UHA-6 and UHA-6S. Soon to be released is a more budget oriented model to replace the UHA-3, called the UHA-4.
The Leckerton UHA-6S sits at the top of the food chain as far as Leckerton products go. It is a portable amp with a built in DAC, and features both USB and optical digital inputs. It has a battery that recharges via USB, and an option to disable charging in case you are using some variety of portable computer. There is a gain selection switch that allows you to choose +6dB or +18dB.
Lurking inside the case, we find one of my favorite DAC chips, the Cirrus Logic CS4398. This chip has been used in all kinds of great products from Marantz, McIntosh, Esoteric, Bryston, Ayon, and Classe. Obviously the implementation is more important than the chip itself, but the fact that those higher end companies have used it indicates that it has lots of potential. Assisting the DAC is the venerable Texas Instrument PCM2705, in this case used to receive the USB data. We also find a total of 4 socketed op-amps, which are easily swapped by the end user if so desired. 2 of them are the Burr Brown OPA211A, used as output filters for the DAC. The remaining 2 are the AD8610 from Analog Devices, used in the output stage for the amp section. I happen to like both choices, but again, the use of sockets means that the user is free to put in whatever they like.
Checking my pictures, you can see how the design is broken down into 2 sections that sort of sandwich together. One is the amp portion, holding the socketed op-amps, and the other is the DAC section with the CS4398, PCM2705, etc. Everything fits together nicely, and the battery has a pad stuck to the side so there is no rattling.
The case is your typical aluminum Hammond style enclosure, nothing fancy but it feels sturdy and well built. Mine is black with a tiny bit of silver trim, but it is also available in all silver. It has “Leckerton Audio” and a “UHA-6S” etched into the front and rear, respectively, and all controls and I/O ports are clearly marked as well. The whole thing is executed rather nicely, but certainly doesn’t have the polish that some of the competition has.
The volume control has a nice smooth feel to it, and I did not observe any channel imbalance, even at very low volume. Powering down the unit is dead silent, rather than the pops and squeals exhibited by many portable amps (or non-portable for that matter). I was also impressed that I did not hear any background noise at all; running on battery, or USB, or even while charging, it is always just silent. All of these little touches add up to make me feel that this is a quality piece of gear.
My test unit spent most of its time as a portable, although I did get a bit of home use here and there. On portable duty, I paired it with a Sansa Fuze, Sansa Clip+, and a QLS QA-350. The QA-350 has an optical digital output, so I was able to use the Leckerton as a portable DAC and amp. Headphones used on the go included the LiveWires Trips, Monster Turbine Pro Coppers, and Unique Melody Aero customs. At home I used a Rotel RDV-1092 player or a Dell Mini to play music, and listened through Grado RS-1, Sennheiser HD600 and HD650, and modded JVC RX700 headphones.
I tried all types of music, from gritty low budget rock albums to audiophile demo discs. I used mostly standard CD quality stuff, either on disc or in FLAC format. I did try some 24/96 material, mostly from the Rotel. The USB input on the Leckerton only accepts CD quality signals, so when using the Dell I had to use an Audinst HUD-mx1 to convert the 24/96 USB stream to optical, which the Leckerton can accept in the full resolution.
I connected it as a USB DAC to several computers, just to test. It worked fine with no drivers needed with Vista, XP, and Windows 7. It shows up as “USB Audio Device”, and I had no problems using kernel streaming or WASAPI.
Big sound from a small package. Note the Rotel player sending 24/96 material via optical, which the Leckerton handles beautifully.
I’m going to keep this somewhat short, since I’ve already delayed this review long enough. Simply put, I found the UHA-6S to sound excellent. It has a nice even tone to it, very smooth with no emphasis in any particular frequency. It has great dynamics, helped no doubt by the inky black background. But it also excels at low volume listening due to the excellent channel balance at low volumes. Even with very sensitive IEMs, I never found one side overpowering the other, as can be the case on many amps.
If I had to choose a sound signature (since “smooth and transparent” is impossible to completely achieve from a portable amp at this price point), I’d say that there is a slight emphasis on the lower end of the spectrum. I stress the word “slight” because it is really not prominent enough of a bump to qualify this as a “bassy” amp. But the bass is very well controlled and has a nice deep extension. Treble is also quite good, extending fairly high and never becoming etched or grainy. It sounds to me like there is a very gentle downward slope as the frequency range rises; not enough to lose much detail but it definitely tends to smooth out what would otherwise be a harsh recording. The flip side of that ends up being just the tiniest bit of missing definition on certain instruments like trumpets or cymbals. This was only really even noticeable when doing direct comparisons to a higher end amp, and I never felt like I was missing out when using the Leckerton on its own.
As far as power, the amp section seems to have plenty to drive most headphones. It is rated to drive headphones from 16ohms to 300ohms, and I found that to be very true. I was even able to drive a set of 600ohm AKG K240DF, and although the combo didn’t perform as well as some others, it is definitely listenable in a pinch. Using the 300ohm Sennheiser HD600, I felt that there was plenty of power on tap. The low gain setting required a pretty good twist of the volume knob, but with high gain set I had plenty of room to spare. At the same time, this amp is excellent for super sensitive IEMs. The LiveWires are a good test for this, exhibiting hiss on many amps I’ve tried. With the Leckerton, they were almost dead silent. On the low gain setting, I was able to dial in a desired volume level with great precision, and again the levels stayed matched on both sides no matter how quiet I had it set.
The Unique Melody Aero triple driver custom is pretty picky IEM. It has a tendency to be uninvolving and even bass shy unless driven with a high quality amp. The Leckerton was a near perfect match, really bringing out the substantial bass capabilities while still preserving the overall flavor. I’m going to review the Aero soon, but for now think of them as similar to an Audio Technica W5000; the bass should be deep, tight, and articulate, but should not be the prominent aspect to the listening experience. That’s exactly what the Leckerton allowed the Aero to do. A more aggressive amp like the Vivid Technologies V1 does not work well, but the UHA-6S is terrific.
Similarly, I really liked what the Leckerton did for my Grado RS-1. I did notice just a tiny bit of airiness missing from the top end, but overall it sounded incredibly good. Bass was punchy and solid, and the soundstage was about as expansive as these Grados ever go with the stock bowls. I mentioned earlier that the highs had a very slight downward slope; it is not enough to deter the RS-1s from rocking in typical Grado fashion. Guitars sounded especially good, with the signature Grado “crunchiness” that reminded me again why the name Grado means world class performance in that area.
Switching gears a bit, I tried some headphones that could be considered a bit darker. With the HD650, I felt that the Leckerton did a good job, but was probably not the best match overall. The highs on the 650 are already pretty mellow, and with the Leckerton they seemed even more recessed than usual. The bass had excellent impact and tone but lacked a bit of control, and overall I didn’t enjoy the experience as much as with some other amps.
On the other hand, the HD600 was great. It maintained a nice weighty feel while filling in most of that missing top end that was absent on the 650. And the JVC RX700, which features something similar to the Sennheiser house sound, sounded equally as impressive. Being a budget headphone, it tends to get shrill and boxy at higher volumes, but the UHA-6S did a commendable job at taming that problem, and for the most part they sounded nice and smooth.
The obvious competition for the UHA-6S is the iBasso D10 Cobra. The prices are nearly identical, both feature low/high gain settings, both have USB and digital inputs for use as a DAC.... in short, they are very evenly matched from a specification standpoint. The iBasso has the advantage of featuring a coaxial digital input, while the Leckerton is limited to optical. It also has the clever ability to give a line-out signal from the input jack, thus enabling it to be used as a DAC only and paired with an external amp. In defense of the Leckerton, it has the advantage of featuring replaceable op-amps for the amp and DAC (as opposed to just the amp section for the iBasso). It is also a local company for those of us in the USA, which lessens shipping time and possibly makes it easier to work out problems should they arise.
Unfortunately I don’t have a D10 here to compare directly. I had borrowed one from a friend for a month or so, and that was a few months back, so my comparison is from memory only. Keeping that in mind, it seems that the Leckerton is slightly better sounding overall, but the differences are rather small. Bass in particular seems more defined and authoritative, and there is a certain smoothness to the top end that seems absent on the D10. This is mostly apparent when using full size cans; with IEMs the amps sound nearly indistinguishable from each other. I know many users are happy with their iBasso units, and I don’t think the Leckerton is substantially better, but if I had to choose one for myself I would likely choose the UHA-6S.
I used my QLS QA350 as a portable transport, via optical connection to the UHA-6S. I compared using the built in DAC in the QA350, which is based on the Wolfson WM8740 and sounds very good. Again the differences were small, but the Leckerton seemed slightly more detailed, and imaging seemed more precise in the soundstage. One area where the Leckerton was very superior was in amplification; using the QLS as transport and DAC, the built in amp sounded a bit rough and gritty compared to going line-out to the Leckerton. That impressed me because I find the built in QLS amp to sound plenty good on its own. But when doing back to back comparisons, the Leckerton totally outperformed it.
I used the UHA-6S in my home rigs, and it was actually a very solid performer. It is about on par sound quality wise with the Audinst HUD-mx1, although it has a very different feature set with the optical input and lack of line-out capability. It did edge out the Vivid Technologies V1 DAC/amp by having a smoother, more even sound, as well as significantly better performance in the DAC section via USB. The Vivid wins when used with the Sennheiser HD650, but the Leckerton wins with just about everything else. I could totally see this product being the centerpiece of a budget system. Add in a cheap CD player or laptop (or both) and perhaps some Grado SR80s or other value headphones, and you would have a very nice system at a modest price.
The Leckerton UHA-6S is a great little amp. It’s versatile, sounds very nice, and has a robust feature set. I like the fact that it has easily replaceable op-amps, and replacement batteries should be readily available for many years as well. Perhaps best of all is the fact that Nick from Leckerton Audio is just a quick email away, ready to answer any questions or arrange for service if needed.
Obviously at a $240 price point, you can’t have it all. There is a small improvement to be had in almost every area if price is no object. That being said, for the price I found the Leckerton to have no major compromises to speak of. The biggest complaint I can find is that it doesn’t pair particularly well with darker headphones. That’s more a matter of voicing than a specific flaw.
One thing to consider is that Leckerton sells another model called the UHA-6. It has all the same specs as the UHA-6S with the exception of the optical input, and it sells for $20 less. Personally I think it is worth the $20 to have that option available, even if only as a “just in case” type of thing. But if you are absolutely sure that you will never use optical, then you might save a few bucks on the cheaper model.
I’d like to thank Nick at Leckerton for loaning me this amp. Now that I’m packing it up to return it, I find myself trying to justify buying it. I absolutely don’t need another amp at this point in my life, as I do most of my listening at home. I sold my iQube and RSA SR-71 earlier this year as I just didn’t find myself using them very often, so I really can’t justify keeping the Leckerton. For what it’s worth, I think it would slot somewhere in between the SR-71 and the iQube, and that’s saying a lot. If you are in the market for a portable amp, or better yet a portable DAC/amp, the Leckerton should be on the top of your short list to consider.
Here you can see the 4 socketed op-amps
Good design the way the 2 boards fit together
This thing is a beast with Grados
Great combo with the QA350 and the UM Aeros