Astell&Kern UW100 MK II: True Wireless Earbuds optimised for audio quality

No ANC, but A&K insists its passive method delivers better sound with minimal compromise in blocking noise.

by Justin Choo

Options are few and far between if you want audiophile-quality True Wireless Earbuds. Fortunately, Astell&Kern (A&K) has just launched the UW100 MK II, which fits the bill perfectly.

Unlike the Sony WF-1000 XM5 and its ilk, the UW100 MK II is no technological canape that can be stuffed into your earhole and rock your world–we don’t do that here, sir. A&K has stuck to a more traditional approach, which means no Active Noise Cancellation–only Passive Noise Isolation (PNI). Perhaps that partly explains the somewhat unconventional pentagonal design of the earbuds, a striking visual motif mirrored by the case.

That said, conventional wisdom dictates that this puts the UW100 MK II at a disadvantage in noisy places or when you need to converse with people utilising HearThrough or Sidetone. But audiophiles are more than willing to lug around a DAP and an amplifier to listen to music on the move, so you tell me what it is they are willing to compromise; I’ll wait.

A&K claims a best-in-class PNI achieved purely through ergonomics: the attenuation is ___ by the earbuds. A&K says their solution is comparable to conventional ANC methods but with the added benefit of cancelling unwanted ambient noise across all frequencies. At the same time, the UW100 MK II offers an Ambient mode where you can choose between four settings. 

The UW100 MK II is built on a single Knowles Balanced Armature (BA), the leading name in BA manufacture. The BA lies in the centre of an unusual design: The BA driver position has been shifted inwards towards the ears to reduce sound diffusion, and the acoustic chamber and mesh have been reshaped to optimise this placement. Presumably, this helps to improve performance when reproducing fine details and dynamic performance.

On the digital front, the UW100 MK II uses a high-end Asahi Kasei AKM 32-bit Hi-Fi DAC for improved sound quality, if not audiophile spec sheet porn. The new version features a revamped design where the digital and analogue components are kept separate to reduce signal noise, improving clarity and separation between instruments.

For transmission, it uses a low-power, “premium-tier” Qualcomm QCC5141 Bluetooth chipset, which supports up to 24-bit/96kHz high-resolution audio and the aptX Adaptive codec that balances the best possible audio quality with low latency. Interestingly, it is specced to support Digital Hybrid ANC, but I suppose this is how they implement Ambient mode.

One good thing about not having ANC is that battery life is longer by default. For the UW10 MK II, you get up to 9.5 hours of battery life and up to 29 hours if you factor in the charging case. The case supports fast charging so you can get an hour’s worth of music with a single charge.

Other quality-of-life features include Qualcomm cVc Generation 8.0 support for clear calls, multipoint, Google Fast Pair, and an AK Control app for basic customisations.

The Astell&Kern AK UW100 MK II retails for SGD439 and is available at AV One, Connect IT,, Stereo Electronics, TK Foto and Treoo.