It’s no secret that I haven’t reviewed a DAP for some time, and I will explain my reasons. Chiefly, I was never very enamoured with the overall experience, the DAPs of old were choppy devices, the early Android implementations buggy and slow. Sonically, some were pretty darn good, but none could ever match even a midrange desktop stack and most high-end models were large enough that portability became questionable. Of course, this is my impression for my own use cases and values, I can see the appeal of having an all-in-one unit; not to mention, having the ability to uphold a consistent, high-quality listening experience at all times whether at home or on the go. It’s very clear that DAPs have come a good way since then and though my life at present is no longer so portable, I found myself relishing my experiences with the SE180. My thoughts and screening tests follow.
Frequency Response –
Testing Methodology: RMAA via Startech External Sound Card
Both the SEM1 and SEM2 modules offer a linear frequency response suggesting that both represent audio with great fidelity. Due to the quality of my sound card, I am unable to reliably test other measures such as distortion and crosstalk so they will be used as a personal reference only. Qualities here can also impact the sound as I will detail via subjective listening.
Output Impedance & Hiss –
Testing Methodology: SPL volume matched comparison through an inline splitter to THX789 + SMSL SU9 to Campfire Audio Andromeda and Ara
The SE180 offers a 1-ohm output impedance via its single-ended output and a 1.5-ohm output impedance over its balanced outputs, this goes for both its SEM1 and SEM2 modules. Through both, even on high gain using my most sensitive IEMs, the SE180 rewarded with a jet-black background. This is a huge plus for low-volume listeners and maximises dynamics range and detail perception.
Output impedance is indeed low, the Campfire Audio Ara is my go-to tester IEM for its low 8.5-ohm impedance and mechanical crossover, able to discern even between 1-ohm and sub-1-ohm sources. Here, it was evident the single-ended output was doing a good job and even the balanced outputs produced only mild changes. Where the 2-ohm A&K Dual DAC Cable was giving me noticeable shifts in tonality, the half ohm difference here does give the SE180 a far more consistent character. While there may be outliers, I feel for the vast, vast majority of pairings, this is more than acceptable.
Even before ABing the SE180, I was certain this was a high-performance source accomplished in every measure. I don’t frequently get this impression from many devices and its strengths were only further ossified to me under comparative conditions. True to Astell & Kern’s marketing, the SE180 upholds a clean and meticulously organised image in all regards. Indeed, there is no glare, no overt brightness to be heard. The background is clean both with regards to noise floor and the player’s note delivery, most noticeable when scrutinising the attack and decay of each, the SE180 sounds very refined and composed even on complex tracks.
The SE180 isn’t a purely linear source in the traditional sense but one tuned for maximum musical enjoyment, a goal it achieves with aplomb. It is defined by its assertive attack and exemplary agility woven together with great cohesiveness. This is achieved as a product of its larger than life note size in the bass and midrange especially, yet simultaneously high note definition and resolution. Meanwhile, the top-end is flattered with a clean and refined voicing wonderfully free of brittleness and grain. While the slightly more unassuming top-end means I cannot call the SE180 an instrument for the professional, suffice to say, I am a fan as an enthusiast. These qualities are fairly consistent between the two modules, a house sound if you will. Of course, there are very noticeable differences between the two in many regards that I will detail below.
AKM vs ESS
The AKM module provides a more immersive soundstage, chiefly, a deeper and slightly wider stage making it more multi-dimension, and with slightly sharper localisation. The ESS module is almost as wide but trades depth for height, its centre image being more upfront. It provides a slightly more resolving foreground in return; the midrange has better resolution and layering, transients decay faster giving is a slightly sharper note presentation, and this forms a more intimate but holographic image overall. I found the ESS module to have a slightly more vivid tonality which no doubt plays a part into this impression.
The AKM module has a heftier mid-bass and, by extension, its midrange comes across as slightly warmer. This is counterbalanced by its slightly daintier note structure. That said, I found the ESS module to offer bigger bass notes, it simply isn’t as warm. The ESS’ low-end is more involving and tactile, being tighter and having a more aggressive note attack while the AKM module prefers greater texture and smoothness. The ESS module is a touch leaner in midrange note weight and also slightly cleaner tonally. It has a little more air around its notes here and better separation due to its greater tonal cleanliness.
Treble is slightly more extended and resolving on the AKM module despite it having a smoother, more refined voicing. I found the AKM module to showcase a slightly darker background yet too which means it comes across as similarly well-detailed despite not being as present. The ESS DAC provides just a little less extension that is, in part, counterbalanced by its more separated voicing. It is a tad airier but not quite as resolving of micro-detail. I didn’t find it be a bad performer by any stretch in the treble but did have a little grain the AKM module didn’t exhibit.
That said, it is again, more revealing in tonality which will suit different preferences and pairings where the AKM module may come across as too smooth and dark. Given that the two modules trade blows, I would definitely posit that the SEM2 module serves as an alternative rather than an upgrade. I found myself enjoying either of the two depending on pairing and found both to represent very solid implementations of high-quality chipsets on A&K’s behalf.
I was stunned to hear upon direct comparison with my desktop stack that the SE180 was able to achieve, if anything, a more tactile bass performance. Moreover, this sustained even on upbeat, sub-bass heavy tracks. The quality of the power supply and implementation here are exceptional. Matching the desktop stack on extension, the SE180 with SEM1 module especially further bolsters this experience with a slight boost to its low-end note size while the SEM2 is warmer, slightly more laid-back but equally well-extended. Both lend the impression of a more robust and powerful bass. I would hesitate to call either forward as the midrange has been empowered to an equal degree. Rather, notes are universally enlarged whilst remaining tonally uncoloured and upholding timbral accuracy.
Attack is ultra-concise, and decay is agile too, delivering excellent pace for a super snappy performance that keeps pace effortlessly on complex passages, the SEM2 to a lesser extent. This is all the more impressive when considering the SE180 has dynamics and control that rival a good desktop source, able to extend and slam with great authority whilst maintaining excellent note definition. This is again, not to be mistaken as a bassy source, it is defined more by its technical accomplishments. Its tactile note presentation combined with its larger than life note size grant the SE180 an intoxicating sense of energy that serves as the driving force behind its sound.
As note size in the midrange has been equally empowered to the bass, the SE180 upholds a balanced character. It is important to note that the midrange doesn’t sit forward, it simply has a coherent and very well-structured note presentation that is nicely counterbalanced by a wide, spacious stage. Though large, notes are wonderfully complete and perfectly filled out though never to the extent of bloat or congestion, imbuing a rich, musical character, the SEM2 epitomizes this impression. If I had one complaint, it would be that this is to the detriment of separation, albeit, this is unavoidable due to the style of tuning. Even on the SEM1 module, I did find that more neutral sources do offer a slight advantage in discerning textural nuances as a result.
The SE180 with SEM1 module prefers a more vivid sound with its larger notes and vocals set to an aggressive note presentation prioritising attack and definition. Meanwhile the SEM2 module is richer and swings further into the organic and coherent approach but with equally defined notes. In so doing, the SE180 remains a well-resolved presentation if not possessing the most revealing character through the midrange altogether. While it isn’t the most discerning of micro-details in the midrange, the tonality on offer epitomises coherence whilst minimising tonal colouration, similarly, timbre once again performs at a high level due to the universal bump in size. The SE180 is clean, musical and highly refined in execution.
By comparison to the bass and midrange, highs don’t steal the show but similarly aren’t overshadowed on both modules. They are defined by their ultra-refined voicing and clean transient response capable of great separating ability and fine detail retrieval in the absence of brightness. Specifically, instruments are well-bodied and slightly organic, highly defined but prioritising texture over clarity. The SEM2 module is the cleaner of the two in the foreground and also with regards to transient response, the SEM1 module being slightly more energetic in return. I found the SEM2 module especially impressive, offering a complete lack of grain and brittleness, chiefly responsible for this impression of refinement and the cleanliness of its overall image. I believe the note presentation showcases true mastery of source design on A&K’s behalf and this applies to both modules. Though not hugely spacious, the SE180 is able to play with its space far better than most sources due to the cleanliness of both its background and note presentation. This is especially so on the more extended and slightly sparkly SEM2 module with the SEM1 providing a slightly more superficially airy response.
Either way, small details fade in and out with uncanny smoothness, showcasing a delicate balance between transient and decay that maximises texture and detail retrieval. While sources like my THX789 provide a sharper note attack, the SE180 is more balanced in its note presentation, and the relative reduction in sharpness permits a more delicate note with greater fine detail density. All the while, its ultra-clean background serves as an immaculate canvas upon which foreground elements pop even in the absence of emphasis. Both modules offer a pleasing linear extension imbuing great headroom and a tinge of additional energy and sparkle, especially on the SEM2 module, that draws focus to micro-details. It is impressive that A&K has so masterfully executed the top-end and have maximised the potential of both modules. Though not for those wanting huge clarity and bite, the SE180 offers a refined voicing and top-level technical ability.
After repeated comparisons, I heard a consistent character from the SE180. And once again, this is a source that performs well when small aspects of its performance are scrutinised but is best enjoyed when zoomed out and enjoyed as a coherent whole. With the SEM1 module installed, its stage doesn’t project hugely in terms of depth, but offers great width stretching well beyond the head with appropriate IEM and headphone pairings. The SEM2 mixes things up by providing a small jump in width and a larger jump in depth, giving it more rounded proportions. The empowered bass and midrange presentation lends a sense of grandness to the presentation on both, while the superb cleanliness of its background draws focus to its multi-dimensional nature.
Imaging is tack sharp and directional cues come through clearly, on the SEM2 more so. The presentation is highly layered and huge contrast can be enjoyed due to the cleanliness of the background. I wouldn’t characterise either module as a holographic as neither have much additional top-end energy, but both certainly offer the resolution and speed to attain this quality on some pairings. The SEM1 module exemplifies this slightly more, though it is less sparkly, it has a faster and slightly more aggressive note presentation. Separation performs at a high level mostly due to the source’s control and note definition though bass and mids especially are not the most revealing, being on the coherent side.
Driving Power –
Fir M4 (6.4 Ohms): The M4 is a very low-impedance hybrid monitor and is highly discerning, showcasing source quality clearly. The SE180 sounded just as dynamic and extended as my desktop stack, delivering even a little more gusto in the sub-bass with a slightly enhanced note size. The SE180 had a faster note presentation with improved tactility and definition. The SE180 provided a fuller, larger midrange expression that smoothed over some fine details apparent on my more neutral sources like the Topping 30-Pro stack. The treble is refined, very well-bodied and sligthly smooth. However, it showcases superlative resolving capability in addition to great headroom and sparkle. It was entirely free of splashiness or brittleness, sounding more controlled. The background was darker than the other sources I tested, further reinforcing this impression. The stage was very wide on the SE180 with both SEM1 and SEM2 modules, wider even compared to my desktop stack, and depth performed at the same level.
Soft Ears RS10 (25 Ohms, 100 dB): The RS10 is deceptively difficult to drive and highly resolving, scaling with sources. The SE180 provided exceptional bass extension, power and control that matched my desktop sources. Some amps such as the THX789 and A30 Pro offered slightly more control, the SE180 came across as more energetic with a pacier, larger note expression. The midrange is also empowered but tonally accurate. Resolving power operated at a high but not top level due to a small drop in separation from the full-bodied note presentation. Treble is refined and free of grain, hugely resolving in the foreground of fine textures and details and with great headroom and extension above, especially on the SEM2 module. The stage was equally wide as my desktop stack on the SEM1 module but not as deep while the SEM2 module was equally proportioned. The SE180 impressed with a cleaner background than any of my desktop sources, a signature quality of A&K.
Final D8000 Pro (60 Ohms, 98 dB): The D8000 Pro is a highly resolving planar with special emphasis on bass extension. The SE180 performs great with full-sized headphones too, further reinforcing its status as a transportable source. I was content with volume 70/150 on high-gain here. The SE180 provided a tight and dynamic low-end but was sligthly less composed on complex passages. There was, otherwise, no drop off or loss of power. My desktop stack provided just a hint more sub-bass pressure but the SE180 had a slightly more robust note presentation in return and was no less defined. The midrange was highly textured, more so than my desktop reference but tonally similar. Treble was slightly smoother and more refined, but very slightly. Detail retrieval matched and the SE180 had a little more sparkle giving it a slightly more vibrant expression. The SE180 matched my desktop sources on width but had slightly less depth and separation.
Suggested Pair Ups
The SE180 achieves wide synergy due to its convincing selection of qualities and relative lack of tonal colouration. The primary area of concern for me would be midrange separation; for headphones or IEMs that may already have a full-bodied expression, you may find the presentation smooths over some fine detail here. This applies to both the SEM1 and SEM2 modules. Otherwise, the SE180 has an excellent tonality and the choice of two modules helps to really fine tune individual pairings. Ironically, I most enjoyed the more vivid SEM1 module with more neutral IEMs and the more expansive SEM2 module with more coloured ones as I found these pairings to enhance musical qualities.
With hugely impressive driving power on both, the SE180 further increases its versatility. For IEMs this rings especially true as it can handily outdo most full-size desktop sources in both responsiveness and resolving power. However, for full-size headphones does glimpse its limits more. A case can be made here for a desktop stack as you do get more power and better power handling on complex passages especially. However, even then, dynamics and control were nigh ideal in the majority of circumstances. The soundstage presentation was especially impressive, able to match a desktop source which has an inherent physical advantage in this regard.