Wednesday, 18 July 2012

The 'Naked' UD100 USB DAC






The ‘Naked’ USB DAC



I was in the market recently to purchase a small, portable USB DAC. Mainly to have a quick upgrade to office set up. Set up here is simply a laptop running iTunes/JRiver connected via 3.5 mm x RCA to a pair of powered Bose Companion II speakers. I did wanted to listen to ARCAM rPAC but have yet the chance to visit the distributor. And when our fellow forummer in the DIY section offered openly to anyone whom would want to review his DIY DAC, I solemnly offered my time to him to do a review.

First of all, a big thank you to hifi4sale.net team for having a platform for hifi enthusiasts to share their interest with others. Secondly, thank you to chchyong89 for having the courage to share your DIY design for review.



The Topography

From the picture above, you know why I call this unit a ‘Naked’ USB DAC. Its physically a clean and bare piece of USB DAC. Main components being the USB, the DAC and the 3.5 mm jack.

The DAC used here is an ES9023 Sabre DAC. Its commercially available and it’s basically a 24 bit stereo audio DAC with an integrated 2Vrms op-amp driver. For more information on the ESS website http://www.esstech.com/PDF/ES9023%20PB%20Rev%200.2aPB%20110117.pdf

It is also a synchronous USB unit. A simple definition:

Synchronous USB connections use a one way digital connection for music replay and are considered the worst type of connection for audio purposes

Asynchronous mode is technically most advanced in that it has a feedback loop so that the amount of data in the frame can be controlled.



It is also a plug and play device which works on both Windows and Mac. No software to install. Just plug in and the computer will detect the USB DAC. It will also be the default audio output for your computer. Need to deactivate it if you want to listen to music through computer speakers.



The Listening Session

Three set up were used for the review.

1. My home set up using Window base laptop, running iTunes/jRiver. The USB DAC was then connected to my MF M6i amp using QED 3.5 mm to RCA interconnect. Played through ProAc D18 speakers.

2. My office set up using the same laptop. The USB DAC was connected using the same interconnect connected to a pair of powered Bose Companion 2 speakers. (NOTE: This is actually the main set up that I intend to find a USB DAC for)

3. Using same laptop and the USB DAC is connected directly to my Shure and Sennheiser IEM.

The same tracks were used in all 3 set up:

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)

5. Time to Say goodbye – Andrea Bocelli (FLAC)

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

Now, don’t be fooled by the miniature size as the result from this DIY unit can be summarized in:

One word – Ingenious

Three words – Size Doesn't Matter

Many many words – One of the best sounding, effective and fuss free upgrade for CAS.

Using Setup 1 at home, there is gap in overall presentation compared to playing my music collection from the NAS via the MF CLiC. Playing La Mer by both artists above via the USB DAC was actually enjoyable. However, it is sort of being amplified as the hiss on the old and original recording by Charles Trenet was more evident then playing it through CLiC. But for more modern recording, there was a slight loss in the details of instruments played on the tracks especially Hotel California. Nothing to fuss about but the Naked DAC presentation loss a little bit of life in the Live ambience of that track. It may also be that for the Naked DAC, I was using the QED interconnect as oppose to Siltech on the CLiC.

When I switch to Enter Sandman, it was hard to spot any difference compared to playing it on CLiC. The Naked DAC gave a similar rock thumping bass drum and the guitar riffs were as metal as it can be.

The most evident however was with Siboh Kitak Nangis. This is a simple and wonderful track by local Miri lass who shot fame in USA by the name of Zee Avi. It is in a local language. It’s a mixture of Norah Jones with a touch of Hawaian music. The Naked DAC injected a new life and experience listening to this track. It gave so much and openness that it made me feel that Zee Avi was performing life in my room.

Now, listening through Shure andSennheiser IEM, in contrary of the designer’s statement in his thread that it is advisable to connect the Naked DAC to a headphone amp, it drove my IEMs nicely. No sound of stress and definitely provided enough clarity and sound level for listeners to enjoy their music without the fuss of a headphone amp.

The last review is meant for the very reason I wanted to get a USB DAC which is to ‘upgrade’ the sound quality in my office. My setup in the office is nothing to shout about. I just connect a pair Bose Companion SII speakers to my laptop.



I know most audiophiles would not even look at a Bose products, but these speakers serve their purpose nicely in my office. But I just wanted to see whether a simple set up (laptop + speakers) can still benefit from a tweak. I don’t particularly like internal laptop tweaks on software nor hardware. I just prefer a plug and play approach. So this Naked DAC was a perfect bill for this purpose. And boy, my jaw literally dropped when I played Siboh Kitak Nangis through this USB DAC. For a simple set up like mine, the USB DAC gave this track a whole new experience to what they call ‘background’ music while you work. In the office I don’t particularly focus on the music as I just need it as a background music while working. But using this USB DAC, work was no longer a focus. I was basically drifted away listening to this track and another track and another track. It created this emotional space for me where I can feel the emotions that the singer was trying to deliver. Similar to the other tracks like La Mer and Time to Say Goodbye. Andrea’s vocals played through the USB DAC and the Bose speakers was so open and spacious that it felt like my whole office was fill with music. Not to mention another colleague of mine stepped in and went ‘Wow….Did you do something to your speakers?’ He too was very impressed that this small USB DAC managed to change the sound quality of simple set up.

The Verdict

Small but powerful, in short. The Naked DAC is definitely a very basic upgrade for CAS but the outcome feels like you have a fully spec’ed DAC box. The only different is its size. Its half the size of the normal thumbdrive.

I cannot say it is value for money as its currently not commercialised.

One recommendation is of course to come up with a proper casing. Then we can call it a Dressed Up USB DAC. The reason for this recommendation is because of its small size, people will tend to make it portable. Hence, it warrants some kind of protection on the exposed DAC chip.

Will the designer sell the unit? Will he mass produce it? Will he be the next Datuk like the father of pendrive Pua Khein Seng ?Smile I let him announce his own plan.

I just wish I had more than 1 week to play around with the DAC.
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