Astell & Kern AK HB1 Review

November 9, 2023 4:38 pm

There are a few different portable Bluetooth DAC/Amps on the market that provide great sound on the go. Products like the BTR 5 bring you mobile apps that let you customize your sound through EQ and other features. Others like the iFi Go Blu bring you a powerful signal that can drive many different headphones and IEMs. Astell & Kern has now entered the picture with their new AK HB1 portable wireless DAC/Amp for $259. Could it possibly match the prestige sound and presentation of their audio players?

What You Get

AK HB1 Portable Bluetooth DAC/AMP x 1
USB Type-C to USB Type-C Cable x 1
USB Type-C to Lightning Cable x 1
Quick Start Guide x 1
Warranty Card x 1

Build

When taking the HB1 out of the box, my first impression it was a bit of disappointment by the lightweight, plastic chassis. A&K usually offers a more elegant presentation and a bit more durability. I was expecting a more solid build akin to their DAC dongles like the HC2. The HB1 feels a bit flimsy in comparison. It does offer a nice volume pot though, as well as options for both 3.5mm and 4.4mm balanced headphone outputs.

Design

The HB1 contains an ESS ES9281AC PRO DAC, supporting DSD256 and 32-bit/384kHz playback. It can also render MQA 8K but hard wiring the HB1 with its supplied cables is recommended to properly unfold it. Small tantalum capacitors are used to ensure a compact build, as well as control power fluctuations, separate from the DAC for more optimal circuitry.

Bluetooth

You’ll see the HB1 advertised with high-quality Bluetooth sound thanks to LDAC and aptx HD CODECs. With that, you also get a very stable connection, with high range and bandwidth.

Battery Life

The HB1 will give you six hours of playback when fully charged. This is an okay battery life, and only takes 1.5 hours to fully charge.

Sound Impressions

If you’re familiar with A&K’s players, then the sound that comes out of the HB1 should come as no surprise. It exercises pure detail and precise imaging with a variety of headphones and IEMs. Especially when you use the 4.4mm balanced headphone output, the HB1 performs its best detail retrieval and transparency, whether or not you’re wired up or using Bluetooth. Of course, wired will sound more like the reference level response you’re used to hearing from A&K, but the sustained tonality of your headphones through Bluetooth still sounds great.

I started out with a few pairs of IEMs, namely the ThieAudio Monarch MKIII which I can’t stop listening to, and a few others. With the Monarch, the HB1 was able to replicate its separation with even greater spaciousness. I even tried a much cheaper pair of IEMs in the Kiwi Ears Cadenza, and a similar separation was present there too. In terms of timbre, the frequencies stay very accurate and realistic. You may not feel as much texture from the bass or highs though, at least not without significant adjustment from the in-app EQ. This makes the HB1 a good companion for flatter IEMs like the Shure SE series or Sennheiser’s IE line.

Moving over to headphones, the HB1 does justice to everything from affordable closed-backs to higher-end audiophile open-backs. The Beyerdynamic DT 770 Pro 80 Ohm version made sense for me to pair with the HB1, and the results were more than satisfying. Sonically, the HB1 stays true to the 770’s sound profile, but you might run into some trouble with headroom with higher-impedance headphones. The HB1 can only just about drive the Sennheiser HD 660s, but the gain should still be comfortable. I also used the Audeze LCD X with the HB1 and I was able to get more room for volume adjustment.

Summary

As far as portable wireless DAC/Amps go, the HB1 offers something that the rest don’t. It’s the only device of its kind that truly feels like the experience of listening to a high-end DAP. Specifically the DAPs of Astell & Kern of course. That is communicated through the HB1’s sound profile, and how it responds with a variety of headphones and IEMs. There are a few disappointing characteristics of the HB1, like the build quality and shorter battery life, but still compares well with Fiio’s BTR5 and the iFi Go Blu.