The Astell & Kern (A&K) HB1 Bluetooth DAC/Amp has a variety of features that will make it a hit for fans of hi-res audio, but if those fans are also console gamers, it’ll be thanks to its support for the USB audio class. What might be even more appealing is UAC (UAC) 1.0 and its headset-friendly microphone compatibility. A&K has also announced its latest high-end portable media player, the Kann Ultra, which offers an interesting and versatile mix of analog outputs. Both new products will be available at select A&K retailers in November. The HB1 is priced at $259, while the Kann Ultra will sell for $1,599.
Estel&Kern HB1 Bluetooth DAC/Amp
The HB1 is absolutely fantastic in terms of features. In addition to being a standard hi-res 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 few audiophile-grade DACs support.
This isn’t the first time we’ve seen a dongle-style DAC/amp boasting its UAC 1.0 compatibility – the recently released budget-priced earphones EA100 also have this feature (albeit with an awkward mode switch). However, the $80 EA100 UAC 1.0 only supports one-way audio from the console — great for better sound, but not useful for games that require a headset. The HB1, on the other hand, supports voice audio in two ways: It has a built-in Knolls mic for those who use in-ear monitors (IEMs) without an inline cable mic (or those who use a 4.4mm balanced output), and a 3.5 mm jack that uses a four-pole, mic-compatible design for headsets or wired earbuds with an inline mic.
As far as its regular audio chops go, the HB1 is comprehensive: thanks to its ESS ES9281AC PRO DAC, it supports native DSD256 and lossless audio up to 32-bit/384 kHz, including if you connect Also includes up to 8x rendering of MQA tracks. HB1 for MQA-decoding devices/apps such as Tidal clients running on iPhone or Android phones. Speaking of iPhone and Android, the HB1 comes with both USB-C-to-USB-C and USB-C-to-Lightning adapter cables so you can work with virtually any device and any platform. There’s also a companion app for both iOS and Android that lets you configure many of the HB1’s settings.
It’s hard not to notice the huge dedicated volume knob on the side of the HB1. This has been a stylistic nod to A&K’s portable devices for years. However, we’re not entirely sure whether this makes any sense for a Bluetooth DAC that might be carried in a pocket or in other places where that knob might be turned inadvertently. We’re also a little surprised that the HB1 doesn’t come with a clip so you can wear it over clothing – an especially important function if you’re going to use it with the built-in mic we mentioned.
In terms of Bluetooth, you get support for multipoint, so the HB1 can be connected to two source devices simultaneously, and it has built-in hi-res audio codec compatibility with LDAC and aptX HD. Strangely, there’s no aptX adaptive compatibility, a strange omission considering that A&K is using a Qualcomm Bluetooth chipset.
Cleverly, the HB1 can be configured to give Bluetooth priority, so if you’re connected via USB and the DAC senses a new Bluetooth session, it will automatically switch. There are also options for how the DAC recharges via USB. Speaking of which, battery life on the HB1 is rated at six hours if you use the 3.5mm unbalanced port or 5.5 hours at 50% volume if you use the 4.4mm balanced port.
Estel and Kern Can Ultra
The latest portable media player from the Kann family, the Ultra will look instantly familiar to A&K fans with its sharply angled aspects and oversized volume knob. What makes the Ultra stand out is its unusual collection of analog outputs – you get four in total: 3.5mm unbalanced and 4.4mm balanced headphone outputs and a combo preamp/line-out output.
The headphone jack has four gain presets and outputs that can go up to 16Vrms – which should be able to drive even the highest impedance headphones smoothly. Preamp/line-out outputs run through a dedicated preamplifier, allowing you to control volume in preamp mode or completely bypass the preamp in line-out mode with four fixed voltage levels from 1.4V to 4V. Can.
Why so many options? The Ultra is designed to be used with just about any analog input you can think of, from high-end IEMs and wired headphones to stereo amplifiers, active speakers and AV receivers. The intention is for people to play all of their digital audio sources – whether they’re streaming music services or audio files stored in the Ultra’s 128GB of onboard storage – through ESS’s own top flagship DAC, the ESS9039MPRO, which can be used with dual -DAC configuration.
As you might guess, the ESS DAC is capable of decoding any digital source up to lossless 32-bit/768kHz and DSD512. It is also a full MQA decoder.
The Kahn Ultra also offers features that were introduced in the A&Altima SP3000, including:
- Digital Audio Remaster technology (DAR), which increases the sample rate of the sound source being played, allowing more refined play and “analog-like original sound”.
- Crossfeed, which mixes parts of the original signal from one channel and sends that signal to the opposite channel with a timing difference to center the sound image, such as when listening with speakers. Settings like Shelf Cutoff, Shelf Gain, and Mixer Level let you adjust the level of crossfeed.
- DAC Filters: Seven DAC filters that let you fine-tune the sound.
- ReplayGain, which maintains constant playback levels between tracks.