Astell & Kern AK UW100MKII TWS ($299): Is the 2^nd gen an upgrade?

Intro: I am a big fan of A&K’s DAP’s. My favorite all-time is the A&K CA1000 & CA1000T. They are the do-all that most would need—a DAP, a headphone amplifier, a streamer, and in a pinch a DAC. The sound is superb, and the OS is tolerable. This follows suit on their already outstanding DAPs. I purchased an older AK120 Titan, and still consider it a sleeper in the used market. That unit pretty much had the industry look up and pay attention to what a portable source could do. Was it expensive? Yes, but the sound quality was worlds better than any portable device up to that point.

With that history in mind, A&K has latched onto the TWS niche knowing full well, that wireless earbuds are here to stay and a huge part of the overall market. As recent as 2021, over 63% of the headphones sold were wireless; so, it makes sense to dip their hands into this segment.

The 1^st gen UW100 was met with both good and bad merits. Good sound quality, but no ANC. A decent alternative to the mainstream competitors, but was that enough? Not one to sit on their laurels, A&K upgraded the MKII with better ergonomics, better BT, a dedicated DAC chip, and good looks. But is this enough?

*This sample was sent to me by A&K for review purposes. The words written are mine for good or ill; there is no influence from the manufacturer.

Specs:

• Bluetooth: Qualcomm 5141 | v5.2 | SBC, AAC, aptX™ Adaptive | HFP, A2DP, AVRCP
• Driver: Knowles Balanced Armature
• DAC: AKM AK4332ECB
• SPL: 94dB (1m@1kHz)
• Earbud Control: Capacitive Touch
• Sensor: Proximity-based
• Mic: 2-mic per earbud
• Playback: Up to 9.5hrs (Max 29hrs)
• USB-C for charging
• Cradle supports Wireless charging
• Android and iOS Control Apps
• Firmware Upgrade via OTA (Over The Air)
• Weight: Earbuds: 7g | Charging Case: 65g
• Dimensions: Earbud: 22.2 x 21.2 x 22.8mm | Cradle: 72 x 32 x 34mm
• Astell&Kern 1 Year Warranty

In The Box:

• UW100MKII Earbuds
• Charging Case
• 5 sets of ear tips
• USB Type C Charging Cable
• User Guide
• Warranty

Comparisons:

UM Free ($349)

Campfire Audio Orbit ($249)

Gear Used:

iPhone 13 Pro Max

Tidal Masters

Qobuz

Unboxing:

Efficient. Coming in a smaller square box, the MKII is of diminutive size for a package. I appreciate this since most often the actual boxes are recycled or disposed of (one hopes recycled…). The unit in near-life size adorns the front cover ahead of the case. The back carries the device specifications, included items, and legalities including where the unit was made (South Korea).

Sliding the sleeve off you find a square box with a covered lid. Removing the lid, you find a small paperboard “pouch,” which contains the warranty card and instructions in multiple languages. Under that, a rectangular box carries the charging cord and five sets of tips mounted on a plastic tray. Efficient again. One tip is mounted already on the unit, which resides in the case, above the rectangular box.

Upon removing the earbuds, don’t forget to remove the protective plastic, which sets over the three charging ports, per side. The unit needed charging upon arrival, which was fine as I was on other reviews. The case is set for both wired (USB-C) and wireless Qi charging. More manufacturers seem to be going this route, which is nice for those who have that aspect at home, work, or in their vehicles (I haven’t tried that…).

Functionality:

After charging, I tried connecting the TWS bud to my iPhone, and through the AK Control app. It failed. Repeatedly. Doing some reading in the manual, I found that upon failure, you could do a soft reset by placing the units in the case and long-pressing for 10 seconds on each bud. You will audibly hear “power off,” then “power on,” which denotes that the unit has been reset. Until then, I was getting a blinking red light on the left bud, which denoted it needed charging again. After the reset, the unit connected and functioned properly.

The MKII also has fast pairing for Google, and once connected to your device will automatically connect to your existing device (if BT is on), which is nice. The MKII can be simultaneously connected to two devices, which means you can listen to music on your computer while you work, and still answer phone calls from your Smartphone. I had our son call me to verify this worked. It did without fuss. He also noted the call quality was good. Not the best of devices I have tried (I often use him as a sounding board for call quality), but good. With only two microphones per side, there is room for improvement.

Once paired, you can use the AK Control app to check battery power and toggle between a set number of EQ Pre-sets. Contrary to other reviews, there is a customizable setting for the user. You may customize up to three personal settings.  Also, you can toggle on/off the “Wear During Playback” setting, which allows you to stop music playing when removing a bud. I will get more into the app in a separate section.

The shape allows for good tactility when toggling through functions on the earbud, with a learning curve, though. With either 1, 2, or 3 presses and a long press, each side controls different functions. Thankfully the most often used ones are single press in Ambient Noise level (on/off, L), and Play/Pause (R). These functions can be customized somewhat, but I prefer to keep the uses in the factory position (plus, I’d forget how I changed them unless I was in the app…).

The tactility was very good overall. Some others are overly sensitive, but not the MKII.

Design/Fit:

With a pentagonal faceplate, the light and shadow change depending on the angle. Understated elegance in the larger, bulbous shape. A vent hole in the lowest section holds the mic, one per side. Isolation on phone calls is good, but not great. Ambient noise is reduced when on calls, which helps.

The larger shape helps you grip the earbuds with ease. Often on models such as this, when you grasp the unit, you inadvertently hit a touch control. Not on the MKII, and you can comfortably remove the MKII or insert it.  I do wish for a deeper nozzle, even though A&K has moved the BA closer to the front, which helps the audio signal into your ear canal.

The smooth shape does help when wearing the unit for long periods, but you may need to go a size up on the tips for a proper seal. I often had to push the unit in with the medium tips, which were mounted. Tips are easily changeable, thankfully.

I do like the design, especially the faceplate, and this makes for one of the more unique designs. Plus, tactility as mentioned is easy when you remember what the functions do.

Technology:

As their literature mentions, most TWS do not come with a dedicated DAC, relying upon the BT setup and source for processing. Using a 32-bit AK-4332ECB DAC gives the A&K a nice leg up. You can even tailor the filter response within the app; which to my knowledge is one of the first I have seen.

The custom Knowles balanced armature takes care of all of the musical needs. While somewhat bass-light, you can tailor that to your needs in the app. As mentioned above, the driver is set closer to the front of the nozzle, for better sound response, deeper inside your ear.

Running Qualcomm’s 5141 5.2 BT set, the MKII can play adaptive aptX, but not LDAC. This may not limit those on an iPhone, but Android users may miss the Sony CODEC.

Battery Life:

One full charge will yield up to 9.5 hours depending upon the ambient noise setting, and the case can provide a total of 29 hours. This is getting close to the industry standard models, and well ahead of the “audiophile” brands, who have dipped their toes into the TWS world. A 10-minute charge (either way) will yield another hour of play, which does fall behind the UM Free, which can give 2 hours on 15 minutes of charge.

I was able to get close to the advertised length, within 30-45 minutes each way (and case-dependent; so, the numbers listed are accurate.

App:

At best, the app is average. At worst, it is lacking in connectivity, with the aforementioned problems noted above. I will add that I am not the only one who had trouble pairing the app, smartphone, and MKII together. Once connected though, the basic features worked well, and changing the standard EQ settings was easy. Battery percentage is shown on the front page as well, which to me is a good thing.

Right below the battery level is the ambient mode toggle, with four choices. This can also be done on the left earbud using two taps. Right below ambient mode are the static choices of EQ, along with up to three customized settings. I spent the majority of time going between “natural,” “bass,” and “balance.” Going from those three in order of most bass to most neutral would-be bass, natural, then balance.

A nice feature is the ability to change the onboard DAC filter, much like you would on your DAP. I will cover those changes in the sound summary, but they include sharp roll-off, slow roll-off, short delay sharp roll-off, and short delay slow roll-off. Differences are pronounced.

Firmware updates are done within the app, and upon first connection, I was prompted to update to the latest. It took about 9 minutes on my 5G home WIFI network.

Sound:

*The summary will be in the stock settings for EQ and filter. Tailoring to your needs will of course change this.

Summary:

I find the MKII to have a semi-typical A&K sound signature. That is a smooth, spritely character with good detail. But there is only so much you can do compared to your expensive A&K DAP. As such, bass seems a bit light, and tip-dependent as well as insertion depth. With good isolation, the bass was better, but keeping the MKII inserted properly was an issue I had. Treble reach was good, giving the MKII a V-shape, which was not overly stretched in either direction. Mids came across as subtly lifted, and forward making for a mild W-shaped signature on some songs.

Vocals carried good weight but felt a little processed, and unnatural. Especially compared to the class leader such as the Sony WF-1000XM5 (or XM4 for that matter). I still liked the overall sound and appreciated that the signature could be tailored by not only EQ setting but also filter choice (I did have a favorite…).

moar:

The UW100MKII presented a familiar sound, for those who have heard A&K DAPs or dongles. Or the MKI for that matter. Detail that can rival, but falls a bit short of its competitors, is still quite good. Separation allows the notes to be heard as a part, and the whole of the production.

Using the app, the basswas definitely enhanced, adding to my listening pleasure. I found that attack and decay were quick, so the notes were still succinct enough not to hinder that detail. A lingering bass is not necessarily a bad thing, but here there was enough push so that you could feel the bass line, but it did not overshadow the rest.

Mids are also pushed forward and percussion in this range is pushed upward, too. This gives a nice 3D presentation, expanding the vertical plane so all parts can be heard without issue. Instruments in this range sound life-like and accurate, but a bit thin. This is becoming a more “delicate” signature than one with good girth to the notes. This is of course not necessarily a bad thing.

Treble hits the right spots for me, with accentuation, but did not become screechy at all. Extension adds to the more voluminous feeling of the overall character. That said, there was some stridency in “S” and long “C” sounds. That sharpness was in part due to the singer, but I still felt it.

The soundstage went higher than deeper, which makes sense based on the above-mentioned characteristics. Depth was average to me, and width above average, giving me a slight out-of-head experience. The air between notes (a near-typical trademark to me of A&K DAPs) was better than the competition in my opinion, which helped counter some of the shortcomings. Oddly, when on the “Movie” EQ setting, there was very good holography on the music I played, which gave more weight (and bass) than the “Natural” setting. I came to prefer this EQ setting as much as “Bass.” The Movie setting also gave the notes a thicker sound, which aided in filling the space without encumbering the signature. Quite interesting.

Comparisons:

The easy comparisons would be to the class leaders such as the Sony WF-1000XM5 or Sennheiser Momentum 4, but to me, the two listed below are more the target for the A&K. Dedicated audio companies, who are just entering the TWS market with full effort, UM & CFA are known for outstanding IEM’s; while A&K is known for DAPs. This to me makes the two below more of the target audience than the class-leaders in TWS earbuds.

A&K UW100MKII ($299) v UM Free ($349):

The Free is UM’s second offering in the TWS world (so I was told by a comment on my review), and as such aimed to hit the sweet spot with its technology and price. Using essentially the same driver as the Mest2, UM very nearly pulled this off. I found the bass to be delightful, and the signature to be near-typical UM detail-oriented. Clarity as a result is as good as the A&K, but with a bit better bass.

In the totality of signature though, the A&K sounds more complete to me. It isn’t that I dislike the Free, but I simply like the signature of the A&K a bit more. And coming from their audio background, if UM can fully develop a competitive TWS model, it could well make for a class-leading offering.

A&K UW100MKII ($299) v Campfire Audio Orbit ($249):

The Orbit came to me, without expectations. As CFA’s first TWS offering, to me, it is a study in design. A kind of feeler-product to see if there is enough interest. I for one, would love to see a TWS offering from Ken, Caleb & Co based upon the Andromeda…THAT might kill the market.

But I digress. The Orbit, for what it is, isn’t really that bad. It simply does not stand out against the competition. It is quite competent, and after my review, I went back for more listening recently; and understand why those who like it, really do. It does follow CFA tuning, and the Solaris2020 is one of my favorite IEMs; even if I have to reacclimatize myself to the signature before completely enjoying it. The same mostly holds for the Orbit. I do find it does fall behind the A&K in the total package, but it really should be offered as a springboard for future development. That’s my take.

finale:

The second version of the UW100 is an upgrade on the first, which many liked. Better functionality on the passive noise canceling means that tip choice plays a larger part in this. Call it what you want, but proper tip fit will counter ANC, mostly. Their philosophy of not adding a noise reduction system, because it degrades the signature holds on point here.

With proper tip choice, outside is nearly non-existent, so there is merit in their statement. If a song demands good quality bass or sub-bass, the A&K presents it with authority. Many of the songs I used were bass-light, which may have tempered my feeling for the bass; but placement of the nozzle had as much to do with this as anything. As a result, I did have to adjust the buds fairly regularly, and these will not work for the gym or inclement weather.

Nonetheless, the A&K UW100MKII is a fine-sounding unit, with features that fall behind the typical top-of-the-heap offerings. The Sony presents a more vibrant sound, with ANC. The Sennheiser offers a very good sound almost on par with the Sony, but Senn’s ANC falls behind the class leader.

If you are looking for class-leading ANC, look elsewhere. If you value sound over ANC, then the UW100MKII is worth a look along with the other audiophile models compared above. They may lack in ANC, and not be the absolute best in sound, but are still worth a look.