Kingrex UD 384/32bit DAC review

KingRex ~ We provide HiEnd but not high price
The above motto was found on the KingRex website and seems quite good description of the company`s products. KingRex describes themselves as a “trend leading designer for PC HiFi for digital stream devices” and being located in Taipei, Taiwan, this certainly sounds believable and makes sense. Taiwanese PC industry is extremely powerful in every meaning of the word and although Taiwanese companies have moved much of their production capabilities to China, the research & development part is still mostly located in Taiwan. This beautiful country has extremely well developed and lively audio scene, be it of entry level or state of the art kind.
A short check of their website reveals an array of handy products like a small integrated Tripath T2020-20 chip based integrated amplifier (with the Battery Power Supply option), a preamp of same size, a headphone amp, three DACs and a small speaker system, all neatly designed and packed with high tech ingredients. These products have already established the KingRex company throughout the world and made it highly recognizable and respected.

The little King…

The subject of this review is Kingrex UD 384/32bit DAC which came supplied with the (optional) UPower battery power supply unit. Although the UD 384/32bit DAC itself can be powered from a regular external 7.5v SMPS, the use of the UPower battery supply is absolutely preferred – for ultimate results. 

Some specs:

The Kingrex UD384 is an async USB DAC and Digital to Digital (USB to Spdif) converter capable of streaming high-definition 32-bit / 384 kHz audio files over USB
Adaptive Clock Generator for Audio Streaming Synchronization
Sample Rates Supported: 44.1Khz, 48Khz, 88.2Khz, 96Khz, 176.4Khz, 192Khz, 352.8Khz, 384Khz
Bit Rates Supported: 16bit, 20bit, 24bit, 32bit
USB 2.0 High/Full Speed compliant
USB 2.0 High Speed PHY Integrated
USB Audio Device Class Specification v1.0/2.0 Compliant
Digital SPDIF Interface:
1 Stereo SPDIF output through
Integrated IEC958 Line Driver
Bit Rates Supported: 16bit, 20bit, 24bit, 32bit
Sample Rates Supported: 44.1Khz, 48Khz, 88.2Khz, 96Khz, 176.4Khz, 192Khz, 352.8Khz, 384Khz
Analog Output : RCA *2 (R & L)
Digital Output: S/PDIF *1
Size: 110x82x24mm
The supplied UPower is a pure DC output battery power supply unit that uses a high quality Sanyo Li-ion battery. Power volume: 2600mA/hr. Included special design for isolated protect circuitry for two Li-ion batteries. CHG/DC OUT switch. Fully isolated the charging and discharging. It will free the AC noise from the charger.


From the outside, both units look almost the same: an elegant rounded aluminum case is a quite refreshing alternative to the prevailing square boxed majority. Three golden RCAs (one for the SPDIF out and two analog audio out) on one side and “DC in” and USB connector on the other side is all there is and all that you will need.

In use

The Kingrex UD 384/32bit DAC graced my system for long enough time to get to know it well. The battery powered supply provided many hours of “juice” to the UD 384/32bit DAC unit and both worked flawlessly. The music it reproduced was always served in a way that kept me interested and provided for many hours of stress-free listening sessions.
DAC units below the 1k price point can sound tiresome or even irritating but Kingrex UD 384 fortunately doesn`t belong to this category.   


After the burn-in period, the Kingrex UD 384/32bit DAC showed strikingly what it is capable of. Being run on batteries, the sounds emanated from a very black background which is surely a characteristic of such units. The sound possessed a very smooth nature but it was very detailed at the same time. These two things are often opposing each other: either the sound is highly detailed and bright or it is smooth but closed-in. Not here though, the Kingrex UD 384/32bit DAC was able to bring both desired traits under one hood, so to speak and that`s harder than it sounds, judging by some other DACs. The 3D perspective was excellent: the virtual soundstage was huge and the depth effect made the back wall disappear quite easily. The image focus was quite sharply defined and holographic in its presentation. The hi-rez tracks (24/96 and 24/192) sounded magnificent and in addition to the more open, airy soundstage, gave even more naturally balanced presentation. Perhaps the lower midrange was just a tad less full than with much more expensive DACs but the bass was excellent nonetheless. This is my frequent observation with products that, although offer incredible value for their price and show great all-around performance, the lower midrange seems to be more difficult to reproduce with all the natural weight and authority. This is the region where expensive units show the difference and advantage. My guess is all this has to do it with much more elaborated and oversized power supplies but I might be wrong; perhaps the secret lies in other finer points of their construction. Despite this minor shortcomig, the Kingrex UD 384 still had plenty to offer and eventually gave a very satisfying sonic impression.
What I really liked with the Kingrex UD 384/32bit DAC was its capability to enable me hear deep into the recording: the excellent transparency and resolution revealed musical details with ease and also helped in making the overall listening experience appear stress-less. 


The late Lhasa de Sela (September 27, 1972 – January 1, 2010) was a very gifted singer-songwriter who was raised in Mexico and the United States, and divided her adult life between Canada and France. Her first album, La Llorona, went platinum in Canada and brought Lhasa a Félix Award and a Juno Award. She lived in Marseille and began to write more songs, then moved back to Montreal and produced a second album, The Living Road. During this time, BBC Radio 3 honored her as the best world music artist of the Americas in 2005. From her second album comes a breathtakingly beautiful song “Con toda palabra” (With All Words):

This music is very well recorded and can easily put the speakers under some stress like for instance at the beginning of “My Name”, the strong bass drum punches shake the room unexpectedly. The Kingrex UD 384/32bit DAC reproduced these bass frequencies with heft and all the drama and also communicated the emotional impact impeccably.
Another very interesting recording is The Modern Jazz Quartet with Laurindo Almeida – “Collaboration” (1964) featuring performances recorded at Webster Hall. The MJQ (vibraphonist Milt Jackson, pianist John Lewis, bassist Percy Heath, and drummer Connie Kay) were joined for this session by the great acoustic guitarist Laurindo Almeida, and the music is certainly very special; a mixture of Jazz, Classical and Samba, played in an imaginative and refreshing manner. The Kingrex UD 384/32bit DAC reproduced the interplay of various instruments with great insight and remarkable transparency. Every detail was easily heard as well as the hall acoustics. This album is strongly recommended in every regard.
One of my favorite Bossa Nova singers is Marcela Mangabeira (born August 31, 1981). She is a Brazilian singer from the state of Mato Grosso. She began her singing career in 1998 and after winning numerous local singing contests, Marcela toured through Spain, Denmark, Germany, France and the UK as a guest singer with BossaCucaNova.

In 2003, she moved to Rio de Janeiro and recorded her first album Simples, released in 2005. Simples is truly a homage to the Brazilian Popular Music. One of my all time favorites is her rendition of “Insensatez”, a famous Bossa Nova classic that Marcela sings extremely sensitively and soulfully.  
It starts with soft synthesized vibraphone sounds emanating holographically high above on the virtual soundstage. The Kingrex UD 384 reproduced it with all the shimmering details and broad tonal color palette one could wish for and soon after that Marcela`s voice followed with a very intimate phrasing that easily enchanted the listener with her soothing quality.
“Voo Sobre O Horizonte” is another song that has no lyrics but still carries profound musical content that, through the Kingrex UD 384 DAC was easily communicated and delivered to the listener.
This music easily takes you to far away places and relaxes the body and soul.

Let me conclude with a fantastic adaptation of the Richard Wagner`s piece (opera) ”Tristan und Isolde”, made for the Lars Von Trier film Melancholia, a science fiction drama, so to speak. Tristan und Isolde (Tristan and Isolde, or Tristan and Isolda, or Tristran and Ysolt) is an opera, or music drama, in three acts composed by Richard Wagner. It was composed between 1857 and 1859 and premiered in Munich on 10 June 1865. Widely acknowledged as one of the peaks of the operatic repertoire, Tristan was notable for Wagner’s unprecedented use of chromaticism, tonality, orchestral color and harmonic suspension.
The opera was enormously influential among Western classical composers and provided direct inspiration to composers such as Gustav Mahler, Richard Strauss, Karol Szymanowski, Alban Berg, Arnold Schoenberg and Benjamin Britten.
The film “Melancholia” actually takes its thematic inspiration from this Wagner opera. The futuristic movie follows a new bride, Justine (Kirsten Dunst), and her sister, Claire (Charlotte Gainsbourg), through a disastrous wedding reception followed by a cataclysmic end-of-the-world scenario in which a rogue planet named Melancholia crashes into Earth. In “Melancholia,” Justine reaches a plane of transcendence just as the rogue planet nears Earth and human life is threatened with total destruction. In both cases, death offers the characters a form of extreme emotional release and all-consuming catharsis. For “Melancholia,” adapting the music from “Tristan” fell to Kristian Eidnes Andersen, the sound designer and music arranger on the movie.
Andersen said that Von Trier initially wanted a lot of sad music but eventually settled on the “Tristan” prelude. The music “puts people in a fragile emotional situation … you open up people’s feelings and to the greatness of the world,” Andersen said.
Sorry for the lengthy introduction but I believe we, the listeners, must be educated as much as possible about the great works of composers that put their entire self into their creations. 
This soundtrack specifically is also one of my favorite ones; the music is very picturesque and had I not known it is an adaptation, I would thought it was originally written with the sole purpose as a soundtrack for “Melancholia”. Yes, the title of the said movie perfectly fits the overall mood; the music creates melancholic feelings but at times it is also dramatic, like the film itself. All in all, a great movie and a fantastic music that, with the help from the Kingrex UD 384 DAC was reproduced with all the tension, drama and emotional charge one could wish for. By all means this is what great audio components distinguishes from mediocre ones and the Kingrex UD 384 DAC belongs into the great category, no doubt.


Kingrex has obviously put a lot of effort and knowledge into their UD 384 DAC and the results are showing. Even without the extra UPower battery power supply unit, plugged straight into the wall, this DAC shows serious performance. However, used with the UPower unit, the sound quality enters entirely different regions, approaching the DACs costing twice or thrice the price. The fact that such great performance is available for a relatively modest price, only leaves one conclusion: my highest recommendation.

KingRex Technology Co., LTD
Tel: +886-2-8226-9561
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