The Astell&Kern (A&K) HB1 Bluetooth DAC/amp has a variety of features that fans of high-resolution audio will love, but if those fans are also console gamers, these features will be even more appealing thanks to support for USB Audio Class (UAC) 1.0 and headset-friendly microphone compatibility. A&K has also announced its newest high-end portable media player, the Kann Ultra, which offers an attractive and versatile mix of analog outputs. Both new products will be available in November from select A&K retailers. The HB1 is priced at $259, while the Kann Ultra will retail for $1,599.
Astell & Kern HB1 Bluetooth DAC/amp
The HB1 is absolutely packed with features. In addition to being the standard high-resolution DAC/amp for wired connections to phones, tablets, and PCs, it also supports UAC 1.0 for wired use with game consoles like the PlayStation 5 and Nintendo Switch. Despite the fact that the newer UAC 2.0 has been around for years, these gaming machines continue to rely on UAC 1.0, which is supported by only a handful of audiophile-grade DACs.
This isn’t the first time we’ve seen a dongle-style DAC/amp touting UAC 1.0 compatibility — a recently released affordable product The Earfun EA100 also has this feature (albeit with an awkward mode switch). However, the $80 EA100 only supports one-way audio from UAC 1.0 consoles — great for better sound, but useless for games that require a headset. The HB1, on the other hand, supports voice audio in two ways: it has a built-in Knowles microphone for people using in-ear monitors (IEMs) without an inline cable microphone (or those using a 4.4mm balanced output), and a 3.5mm jack. mm which uses a four-pole design that is compatible with microphones for wired headsets or earbuds with inline microphones.
As far as its regular audio chops go, the HB1 is comprehensive: thanks to the ESS ES9281AC PRO DAC, it supports native DSD256 and lossless audio up to 32-bit/384 kHz, including up to 8x MQA track rendering if you hook it up. HB1 to an MQA decoding device/app such as a Tidal client running on an iPhone or Android phone. Speaking of iPhone and Android, the HB1 comes with USB-C-to-USB-C and USB-C-to-Lightning adapter cables so you can work with almost any device and any platform. There are also companion apps for iOS and Android that let you configure some of the HB1’s settings.
It’s hard not to notice the large dedicated volume knob on the side of the HB1. This has been a style hallmark of A&K portables for years. However, we’re not entirely sure whether it makes sense for a Bluetooth DAC that might be tucked away in a pocket or some other place where the knob could be accidentally turned. We’re also a little surprised that the HB1 doesn’t come with a clip so you can wear it on clothing — a particularly important function if you’re going to use it with the built-in microphone we mentioned.
In terms of Bluetooth, you get support for Multipoint, so the HB1 can be connected to two source devices simultaneously, and there’s high-resolution audio codec compatibility with LDAC and aptX HD. Surprisingly, there’s no aptX Adaptive compatibility, an odd omission considering the A&K uses a Qualcomm Bluetooth chipset.
Cleverly, the HB1 can be configured to give Bluetooth priority, so if you’re connected via USB and the DAC detects a new Bluetooth session, it will switch automatically. There is also the option of how the DAC is recharged via USB. Speaking of which, battery life on the HB1 is pegged at six hours if you use the 3.5mm unbalanced port or 5.5 hours if you use the 4.4mm balanced port, at 50% volume.
Astell & Kern Kann Ultra
The newest portable media player in the Kann family, the Ultra will immediately look familiar to A&K fans, with its sharply angled aspects and large volume knob. What makes the Ultra stand out is its unusual collection of analog outputs — you get a total of four outputs: 3.5mm unbalanced and 4.4mm balanced headphone outputs as well as a preamp/line-out combo output.
The headphone jack has four gain presets and an output that can reach 16Vrms — which should be able to drive even the highest impedance headphones with ease. The preamp/line-out output is run through a dedicated preamplifier, allowing you to control the volume when in preamp mode or bypass the preamp completely in line-out mode, with four fixed voltage levels from 1.4V to 4V.
Why so many choices? The Ultra is designed to be used with almost any analog input you can think of, from high-end IEMs and cables headphones to stereo amplifiers, powered speakers, and AV receivers. The goal is for people to be able to run all their digital audio sources — whether it’s streaming music services or audio files stored on the Ultra’s 128 GB of internal storage — through ESS’s flagship DAC, the ESS9039MPRO, used in a dual-DAC configuration.
As you might expect, the ESS DAC is capable of decoding almost any digital source, up to 32-bit/768kHz lossless and DSD512. It is also a complete MQA decoder.
Kann Ultra also provides features introduced on the A&Ultima SP3000, including:
- Digital Audio Remaster (DAR) technology, which increases the sample rate of the sound source being played, allows for smoother playback and “authentic analog-like sound.”
- Crossfeed, which mixes parts of the original signal from one channel and sends the signal to the opposite channel with a time difference to concentrate the sound image, as when listening with speakers. Settings such as rack limit, rack gain, and mixer level, allow you to adjust the crossfeed level.
- DAC Filters: seven DAC filters that let you fine-tune the sound.
- ReplayGain, which maintains consistent playback levels between tracks.