REVIEW: NuForce µDAC-3 (a.k.a. uDAC-3, a.k.a. micro DAC-3)
Tuesday, December 24th, 2013
by Arly Borges & Warren Chi
The NuForce µDAC-3 is a pocket-sized high resolution 24-bit/96khz DSD-capable USB-powered DAC/amp combo that's a perfect fit for the on-the-go laptop-carrying audiophile. With its compact form factor it's also an excellent option for those whose desktop real estate is at a premium, or the CIEM geek looking for a great mini rig for their sensitive CIEM's. Its beefy volume knob, no-hassle plug-and-play installation, $125 USD price point, and pristine build quality make the µDAC-3 a must have for any serious audio enthusiast.Specifications
Input: Micro-USB
USB: 1.1, 2.0; asynchronous
Bit Rates: Up to 24-bit
Sampling: 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz
Output (Analog): RCA (L/R) @ 2Vrms
Gain: Up to +6dB
Dynamic Range: 90 dB
S/N Ratio: 98 dB
THD+N: 0.05%
Digital Output: Coaxial S/PDIF 75-Ohm
Headphone Output: 80 mW x 2 @ 16-Ohm
Power: USB Bus Powered, 80 mA/5V
Dimensions: 68 x 38 x 21 mm
Includes: Micro-USB cable (1 m)
Features
For several years now, personal audio enthusiasts the world over have been enjoying NuForce's popular µDAC series of entry-level USB DAC/amps as their first foray into high fidelity. The µDAC-3 is the third (duh) and latest iteration of this series. While much was carried over from its predecessors, the µDAC-3 offers a series of noticeable upgrades.
Like the µDAC and µDAC-2 that came before it, the µDAC-3 is a small and [trans]portable bus-powered unit that fits nicely into a laptop or messenger bag. It maintains the exact same form factor as previous µDACs: It's about half the size of a deck of cards. Also preserved is an oversized volume knob that makes level adjustments both quick and easy.
Unlike its predecessors, the µDAC-3 is now an asynchronous 24/96 DAC (the µDAC was 16/48 while the µDAC-2 was an isochronous design). The µDAC-3 also features limited DSD support, which is pretty much unheard of at the µDAC-3's price point of only $125.
Additionally, the µDAC-3 now utilizes a micro-USB port instead of a full USB-B port. While this may not seem like a very big deal, the road warriors among us welcome this change. Since we are likely to be carrying another device that requires a micro-USB cable, we can simply share that cable for the µDAC-3! One less thing to carry in our travels.
And finally, NuForce has continued to improve their analog channel balance. This is covered in more detail below. But in short, we no longer consider channel imbalance to be a very big deal at all... unless you're anal, or an *******, or any combination thereof.
Design & Usability
The µDAC-3 is a clean and simple device with very little clutter or complication.
The rear of the unit sports analog RCA outputs (L/R) as well as a coax digital output - which allows the µDAC-3 to function as a USB-to-SPDIF bridge - if you're into that kind of thing. There is a micro-USB input for signal and power, via the supplied USB-A to micro-USB cable. That's it. The µDAC-3 is completely bus-powered, no AC adapter required.
The front panel is likewise uncluttered and utilitarian.
An oversized analog volume knob dominates the left of the unit (or the top, depending on how you have it oriented). It is a welcome advantage from competing units that only provide software-based volume controls.
And for those of you who are environmentally considerate, the volume knob also functions as a power switch for the µDAC-3's amp section - turning it all the way to the left will power down the amp stage.To the right of the volume knob, there is an LED indicator that turns blue to indicate power up, and white to indicate signal lock. On the far right, there is a single 1/8" (3.5mm) TRS jack for your headphones or IEMs.
We should also mention that the µDAC-3 is available in your choice of three anodized finishes: black, silver, and red. I opted for the black one. Warren left things to chance and received a pimping red evaluation unit, which he does admit looks rather striking.
*Note to NuForce: a limited-edition version in gold and silver - not unlike what you did for the µDAC-2 - would be a nice option. It would make an attractive gift for those special people in our lives (i.e. significant others and spouses) who don't necessarily obsess over sound quality, but can still appreciate a pretty-looking, magic sound box doohickey.
Performance (General)
Since Warren and I are both PC guys, most of our tests were conducted in Windows. We assume that you beautiful Mac people have it easier than us - you almost always do - so we won't fret over the breezy experience you're likely to have. But, if by some chance you don't have an easy time, well... sucks to be you!Set-up was a cakewalk, with the µDAC-3 being largely plug-n-play. The one exception to this was enabling DSD support via Foobar2000, an ordeal reminiscent of defusing an explosive device. Luckily, NuForce has posted a fairly detailed set of step-by-step instructions (complete with screenshots) outlining the process. That certainly helped a great deal.
Over the course of several weeks, the µDAC-3 rendered everything we threw at it without a hitch. Well, everything that it supports of course. MP3s (VBR/CBR), 16/44 WAV files, 24/96 FLAC files, and even DSD64 files all played with no issues on Warren's end. On my end, MP3's (VBR/CBR), WAVs, as well as 16/44 and 24/96 FLACs, ACCs and AIFFs were handled flawlessly.
Basically, the µDAC-3 functioned as advertised and expected, with no issues at all.
Performance (DAC)
One of the new features in the µDAC-3 is an asynchronous design for reduced jitter. We're just going to assume that this shift to an asynchronous design has helped, since we didn't notice any significant flaws typically attributable to jitter from an audible standpoint. Matter of fact, neither Warren nor I experienced any errors in the form of skips, stutters, drop-outs or loss of signal lock during our evaluation periods.
If you are intending to use the µDAC-3 for its DAC-stage only, here's a little tip for you. The µDAC-3 is capable of providing up to +6dB of gain via its analog outs, depending on where you've dialed in your levels via the volume knob. Setting the volume knob at approximately the 1:00 position should yield you unity gain from the µDAC-3, thus ensuring that you are neither depriving nor deluging your intended amp.
My experience with the µDAC-3 as a DAC indicated that it was natural sounding with a slightly mellow tinge throughout. I was impressed most by its consistency. No matter what music I threw at it, the DAC seemed to have a tendency of disappearing and embellishing very little of its own character, letting the ear/headphone shine or fall flat on its drivers according to its tuning. Needless to say, the µDAC-3 is a surprisingly revealing piece of kit for its price point. The highs had nice energy but were never strident. The mids had a fluid, yet linear feel with a bit of energy in the upper mids. The lows happily meandered along with the rest of the signature never overshadowing the frequencies.Warren's experience with the µDAC-3 as a DAC mostly mirrored mine in that he heard a warm and easy-going low end that gradually came forward, peaking brightly in the upper mids, before falling off in the highs. This tended to be true regardless of which amp he used (Woo Audio WA7, Objective 2). He also found the µDAC-3 to be fairly revealing for a product at this price point.
At 1:19 of Michael Frank's "One Day In St. Tropez" from his Time Together album, he swore that he could hear - buried within the percussion - "someone's fat ass torturously creaking a chair to within an inch of its life." Understandably, he also found the µDAC-3 somewhat unforgiving of lower quality source files. Lossy files generally exhibited bits of smearing and congestion in spots. It wasn't anything he couldn't live with, but he did note that lossless and high-res files were the way to go with the µDAC-3.
Performance (DAC/Amp)
Much ado has been made regarding the µDAC-2's channel imbalance issues in the past. Paying special attention to this, we are happy to report that any remaining channel imbalance is trivial at most. With my sensitive customs, the UERM and 4A, I noticed nothing worth noting and was satisfied with the acceptable headroom the uDac-3 provided. For Warren, there was an ever-so-slight channel imbalance at the 09:05 position that favours the right channel. But at this low of a level, that is absolutely nothing to worry about. 09:05 is well below normal listening levels. Even for Warren. And he's one of those freaks that everyone likes to make fun of for how quietly they listen.
A more pronounced channel imbalance occurs at the 08:45 position, again favouring the right channel. Honestly though, 08:45 is the real-world equivalent of an audible murmur - and would only bother those of you that are approximately 1/10-scale (6" or 7" tall). And if you're only 1/10 scale, we can assure you that such a channel imbalance is among the least of your problems in life. For example, getting the µDAC-3 unboxed and plugged-in would be far more of a challenge.
The µDAC-3 as an DAC/amp combo was rather interesting for me. I ended up pairing it with a multitude of headphones, including Beyerdynamic DT1350, MrSpeakers Alpha Dog, Fire Pheonix Audio Paradox, and an AKG Q701. To be thorough, I tested several earphone pairings as well: an Heir Audio 4A, Ultimate Ears Reference Monitor, Monster Pro Copper, and RHA MA600, just to name a few.
Overall, I found the µDAC-3 pairs up quite nicely with most of my gear. What impressed me the most was how well it seemed to synergize with my prized Ultimate Ears Reference Monitors. The UERM has long been regarded as a very detailed and neutral custom earphone which is revealing of both the source material and the audio chain it's linked to. With the µDAC-3 the UERM became completely transparent and even more revealing of the source material that was thrown at it. The pairing became - for me - a wonder that emphasized natural-sounding transparency and control throughout the frequency range.
Warren paired the µDAC-3 with a range of headphones and IEMs representing various signatures - including an Etymotic ER-4PT, Tralucent Audio 1Plus2, Sennheiser HD 650, Audeze LCD-X, Audeze LCD-XC, and several others. Like me, he found the µDAC-3 consistently lent every pairing a pleasing and non-offensive signature.
The sub-bass was soft and courteous, with an easy-going roll-off at the bottom. This allowed for a sense of gravitas without any accompanying fatigue. Bass response was generally impactful, though it could be a little warm and wet with bass-heavy tracks. This is not to say that the bass was boomy, because it wasn't. Low frequencies just decayed more slowly and naturally with the µDAC-3 than they would with an analytical sounding amp.
The lower mids were good, with very little bass bleed to thicken them up. There was an energetic bloom in the mids, transitioning from the lower mids to the upper mids, resulting in a bit of shoutiness (but not sibilance) in certain vocal presentations. The upper mids themselves were slightly forward, and carried a good deal of energy. In most cases, this manifested as an exciting snap. But with sensitive, mid-forward IEMs, these same upper mids could be a bit edgy at times. However, the highs were very well-behaved - being both relaxed and gentle on the ears - making the µDAC-3 shimmery, but not strident.
He also found the µDAC-3's detail retrieval to be surprisingly good for a $125 unit. On more than one occasion, he noted that the µDAC-3 came very close to the HRT MicroStreamer in terms of resolution, without the overall tendency towards brightness that the latter is prone to exhibit. Given that the MicroStreamer costs 50% more than the µDAC-3, this was an impressive finding. Compared with a similar product in the same price range, the µDAC-3 out-resolved the HRT HeadStreamer (now HeadStreamer Mobile), which again bodes well for the µDAC-3. Staging tended to reflect the characteristics of whichever headphone or IEM was in use at the time, though imaging was very solid in all cases.
Conclusions
The µDAC-3 was an unexpected but welcome surprise for us, on many levels. Its compact size and durable build beg you to take it with you on your travels. And since the µDAC-3 uses a Micro-USB cable, which is likely already in your laptop bag, it saves you some room as well.
It supports pretty much everything out there - including whatever we threw at it - up to 24/96, and DSD support. We certainly didn't expect that, but are more than happy to have the feature (which worked splendidly by the way). The DAC performed very well, exhibiting no major errors of any kind, and played harmoniously with our amps. And when the µDAC-3 was feeding its own amp stage, it offered us a consistently pleasing and engaging signature that was not offensive in any way.
The bass response was warm, mellow and easy-going, without being boomy or fatiguing. With a respectable amount of bass control, the µDAC-3 kept our lower mids relatively free of bass bleed. Mids exhibited a linear fluidity as they gradually came forward in the upper mids, carrying a good sense of energy to keep things lively. And the highs were very well-behaved, energetic enough to be shimmery, but not at all harsh or strident.
And of course, there's the detail. Both Warren and I were tickled to find that the µDAC-3 was very revealing for a product at its price point (MSRP: $125.00) - able to retrieve detail well beyond our expectations. Because of all this, it was a no-brainer adding this to our stocking stuffer guide, which is exactly what we did. We highly encourage you to try it out at your earliest opportunity. We're certainly glad we did.
