Hardware Reviews

Henry Audio USB DAC 128 MkII


An asynchronous USB DAC for tweakers and music lovers alike, Henry Audio has taken over where QNKTC left off to provide a different take on the challenge to make computer audio as hackable as the software used for playback.

Henry is a USB DAC with a difference. It was created as an open source project by a group of audio nuts around the world with the aim of being upgradeable and tweakable by end users. This DAC started out in life as the Audio Widget project and became QNKTC or Quantisation Noise Killed the Cat which went through three iterations; AB-1.0, -1.1 and -1.2 that were modular for ease of upgrading. You can see my review of the AB-1.2 here. In its latest 128 MkII incarnation the converter is no longer modular but it has been designed so that the hardware can be easily tinkered with. And, just as importantly if not more so, the design is stable and bug free. This was achieved for the commercial release of the QNKTC and remains the case with Henry Audio, a name chosen in order to broaden its appeal.

Børge Strand-Bergesen runs Henry Audio from Norway and sells the DAC directly around the globe. For the MkII version he made a number of changes, not least a big increase in the internal capacitance from 22mF to “nearer 600mF”, he did this by using four different capacitors in order to supply the required current spectrum. Big caps give more power but are relatively slow, so this DAC combines large and small examples in order to provide juice at the right time and in the right quantity for all circumstances. The Henry is a USB powered DAC so intelligent use of the 5mV available is crucial. The MkII also has extra power filtering and an active current limiter to avoid big spikes on plug in – the noise you sometimes get through a system is not a good thing.




At its heart the Henry retains the same AKM4430 converter chip that was used on the original Widget project, a delta-sigma DAC that remains well suited to the task according to Børge. The output stage is on this chip, which avoids the need for separate op-amps. The MkII remains true to its forebear’s tweakability inasmuch as the schematics are published and the source code remains open, and this as far as I am aware makes it unique in the audio world and a lot of potential fun for the audio hacker.

There is a lot of info on the Henry site about getting the best sound quality out of a PC, it provides an open source ASIO driver for a start, but not enough about how Børge hacked his CD player so that its buttons control the audio software on his computer, that sounds pretty cool. The Henry MkII has a slightly smarter box than its predecessor on account of new bolts, feet and RCA output sockets. There’s not a lot else to change without making a new box. Slightly controversial is the use of a mini USB connection rather than the USB B socket found on all other DACs, there are plenty of cables around for this purpose but not many of them are designed for maximum sound quality. AudioQuest making the only examples to my knowledge.

Used with a Macbook Air running Audirvana Plus software the Henry MkII produced the sublime sound of In The Country’s Can I Come Home Now piano piece (Jazz at Berlin Philharmonic II, Norwegian Woods) in an open and very natural fashion. It delivered much of the power if not the full pace of ZZ Top’s Enjoy And Get It On, but that’s judging by high standards, it’s hardly lazy. The bass on James Blake’s Limit To Your Love seemed slightly overdamped by comparison with full size, mains powered converters, but on acoustic guitar from Kenny Burrell (Guitar Forms) it gets most everything right. There’s oodles of space, the speakers disappear and the tone is gorgeous – not a bad result at all.




Changing to some AudioQuest interconnect for the purposes of a comparison with that company’s Dragonfly DAC, a rather more affordable asynchronous design with 3.5mm minijack output, resulted in a another large scale image this time from Javier Perianes’ piano (Manuel Blasco de Nebra Piano Sonatas). Here the image could have been better defined and seemed to lack precision but it was not overblown. The Dragonfly by comparison provided more perspective and focus in the context of a smoother delivery, but it was also less revealing and weaker at low frequencies. It produced a simplified version of events that while very musical does leave out a lot of fine detail. Going back to the Henry makes for more colourful and dynamic listening that reflects the nature of the original recording very well. A good example sounding vibrant and energised with strong groove and excellent double bass – the work done on the power supply clearly providing a benefit in this respect. It also copes with the elasticated blues of Captain Beefheart’s Lick My Decals Off Baby pretty well, delivering plenty of pace from this lively piece. The more reflective instrumental Peon, from the same album, offers up its shimmering beauty rather well too.

The Henry 128 MkII is not the most exciting propositin in the world of portable DACs and in a world dominated by sharp marketing and big specs it has its work cut out. The price has also risen significantly since the MkI putting it into contention with very slick portable DACs from iFi and Geek to name but two. However if sound quality is what you are interested in this converter is more than worthy of your attention. If you are interested in tweaking it’s in a league of its own but even if you are only looking to get the best sound out of your computer I recommend you give it a try. Henry Audio is a classic case of not judging a book by its cover, it’s what’s inside that counts, that and what it sends outside of course.


Asynchronous USB Audio powered by Golledge high-quality crystal oscillators at 22.5792 and 24.576MHz
Supported sample rates: 44.1, 48, 88.2,96, 176.4 and 192kHz
Analogue output: RCA (phono) stereo outputs
Asahi Kasei AKM4430 DAC
Atmel AVR32 general-purpose MCU programmed in open
source C
ASIO driver for Windows programmed in open source C
Low-noise 3.3V ADP151 LDOs powered from USB
Size: W: 114.4mm, H: 32.8mm, D: 128mm
Weight: 300g

Price when tested:
€260 inc delivery
Manufacturer Details:

Henry Audio
T +47 90639918




Jason Kennedy

Distributor Details:

sold direct

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