The subject of this review is their flagship DAC, the UD384 ($590 RRP). Released in 2012, it’s a high resolution 384kHz/32bit digital-analogue-convertor that includes just a single USB input. It also works with the optional U-Power battery power supply ($295 RRP) and can be purchased as a bundle from Australian distributor Crux Audio for $690.00.

Unpacking the UD384, I was greeted by a strong, black aluminium case. The DC power connector, USB "B" socket and a power LED are situated at one end, while three chassis-mounted gold RCA-style sockets are at the other end; one each for Audio Out Left, Right, and Yellow S-P/DIF output.

The U-Power battery supply has two power connectors - one for the UD384, and the other for the power pack for charging. Both units come supplied with a small switch mode wall plug, and the U-Power battery also has a 7.5V connecting cable to power the DAC.

With no obvious “front” and “back” of either unit it makes for somewhat awkward desktop placement; cords hanging out either end. A little messy unless you hide the units away. My Audio Metallurgy GA-0 interconnects are reasonably rigid, so it does leave the UD384 hovering on an awkward angle on top of my system.

Connecting the UD384 DAC and making the power connection by way of the included wall-wart, connected to a Raspberry Pi streamer, initially the audio was playing back at double-speed and very distorted. Google came to the rescue and a newer Kingrex firmware was discovered and quickly applied. Onwards and upwards.

The clarity of the sound from the UD384 was immediately noticeable, conveying a real sense of spaciousness and transparency. For such a little box (and a relatively affordable price tag) this unit has all the musicality and finesse I would expect from a much larger, more expensive DAC. Impressively, I also found extra detail and crispness over other DACs at this price point.

Particular background sounds in Damien Rice's ‘9 Crimes’, along with the little dog barking and lightning strike in Deeper Blues' ‘Underground’ were all there, and clearly defined. Being entirely critical, the only thing lacking a little was in the lower bass region.

It makes sense to pair the Kingrex UD384 with suitably priced components. The LSK M4 (modified) bookshelf speakers seemed a good match, and they’re more than able to produce the lower notes when asked to do so.

Not wanting to be too quick to judge the UD384, the next test was with the provided U-Power battery supply, which had been charging for a few hours. The bright blue "Charge" light had gone out by now, and flicking the switch from "Charge" to "Supply" gave a green light, indicating it was ready for action.

While I think utilising the U-Power provided crisper and clearer highs with the battery supply, it is very subtle and at this entry level of audio, a system can only be so resolving. The bass was, for all my listening, the same as with the wall wart power supply. Walking through my typical auditioning playlist, Dire Straits' 'Walk of Life' has a tell-tale cymbal at the beginning of the track. Any hint that what you hear isn't a hard-tipped drumstick hitting the metal is a dead giveaway that something is amiss in the reproduction system. No fear, it's all good from here.

The Kingrex UD384 seems quite capable when converting your USB-connected media stream into a very well presented Analog audio source. Testing 384kHz sample rates, as well as DSD streams worked quite seamlessly.

Although I was not able to get the S/PDIF output to lock at 48 or 96kHz to feed another DAC as a comparison, this is really secondary to function as the Analog audio outputs are more than good enough. If you have a system capable enough in the low end bass, you may not even notice the dB or two which I seemed to be missing from the lower frequencies of this unit.

Kingrex is distributed in Australia by Crux Audio.