UD120 USB DAC Mini Review

El Hefe

Well-known member
Jun 21, 2008
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It has been nearly 2 weeks now that I have been playing with this review unit. And boy.... how does Stoner Acoustics cramp all the juicy quality into a small device like this... is beyond me. Yes, people may think its exaggerated, but hey.... do you see many companies going for thumb drive sized USB DAC? You have Dragonfly Audioquest but I can tell you, Stoner Acoustics was already launched his first model of UD100 before Dragonfly was out.


Not only it now comes with a 'tail' but the designer has also shy away from the naked and heat wrap design previously found on UD100 and UD110

It was professionally packed similar to any other USB thumb drive and comes with a plastic protective cap. The output jack is also gold plated.

Overall, its more towards a rugged portable USB DAC.... and a true definition of portable.


Mirrored from Stoner's blog, its stated as below.
-USB Audio Class (UAC) 2.0
-16/24/32 Bit @ 32/44.1/48/88.2/96/176.4/192/(352.8/384 asio) kHz

There is also warning that the unit runs hot and needs good ventilation but I did not face that experience.

Further research in the DAC chip it is actually a Texas Instrument DAC which is also used in the higher priced M2Tech HiFace DAC.


iMac playing ALAC, MP3, FLAC
Dell Windows 7 based laptop (for function test only)
BOSE Companion II speakers using QED interconnect
RHA MA750 earphones


To make it consistent to the review of previous models, I have used the same tracks (except for Andrea) with an addition of a 384 kHz music sample I have from my review on Kingrex DAC last year.

1. La Mer – Kevin Kline (MP3 48kHz, 320 kbps)

2. La Mer - Charles Trennet (MP3 48kHz, 320 kbps)

3. Siboh Kitak Nangis – Zee Avi (MP3 48kHz, 320 kbps)

4. Enter Sandman – Metallica (FLAC 192kHz)

5. Time to Say goodbye (replaced by Amazing Grace) – Andrea Bocelli (FLAC 192 kHz)

6. Hotel California (LIVE)– The Eagles (FLAC 192 kHz)

7. 384 kHz sample.... some classical music.


Kevin Kline deep voice is more apparent and toned. The sound of the hi-hat also sounds crisp and lively. Though it is a mellow song but during the music sounds very 'cheerful'. During the violin solo, it sounded layered and rising up across my work station.

On the original track of La Mer by Charles, the UD120 is unforgiving for bad recording quality. The version I have is actually was not really a remastered copy hence it sounded a bit noisy and harsh. The hissing is much more evident from the predecessor DACs.

My favourite local lass artist, Zee Avi.... again is the highlight. The UD120 further enhance the ambient from this track. The overall presentation sounded elevated and just airy that it makes you feel like it was coming from a grander speakers than just these BOSE speakers.

Enter Sandman was presented in a rather heavy and bold fashion as intended by the group themselves. It puts a more genuine originality presentation from the heavy metal quartet. The weight of this track can really make your adrenalin flowing and it was definitely the UD120 that injected that realism.

Andre Bocelli's rendition on this literally made me shed a tear. It was really soulful and the UD120 delivers that very high emotion on this track. It cooks out the simplicity of his vocals and minimal instrument as background. I may upload a sample of this track soon.

On Hotel California, there is some natural improvement from its predecessor. A more energetic experience where the performance was close to a live performance ambient. It was still not really 'there' with regards to a full fledge Eagles standard.

Now the bombshell of why someone should have this unit. Testing of a raw and native 384 kHz file. Recorded and digitized such. I dont know the track name but its some classical piece. This track just further reconfirming of Stoner's design specialty....soundstaging. Everything just sounded uplifting, airy, alive and just boosted in every way possible....and all in the right amount which provides a very tonally balanced presentation. And this is just coming through a pair of computer speakers!!!

As an addition, I tried the DAC with my RHA MA750 earphone that I really love. Despite everyone keep saying that these USB DACs are not capable of driving earphones or headphones, I find it that it has no issues to present a very faithful experience though earphones.

NOTE: On functionality, I also installed the driver supplied by Stoner for Windows based laptop. And I can confirm that it has no issues for Windows 7. Just a few clicks and its all installed with no hick ups.

It can also be used directly with Samsung Galaxy Note 3


A fiiiinnneee improvement from the siblings UD100 and UD110. Stoner has taken into account all the feedback given by his loyal supporters on physical design, updated resolution requirement and still provide a fun musical experience at a modest man pay scale.

It excels in soundstaging where the improvement can be easily experienced on modest computer system. Do note that I did not test it on my full scale hifi set up as I only see the usage of this unit for my office workstation.

I also believed this is currently the smallest 32 bit 384 kHz capable USB DAC.

At USD69 per unit.... relatively.... its a bargain.