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Discussion Starter #1
MSRP: $129
Performance: :4.5stars:
Feature Set: :4stars:
Ergonomics: :4.5stars:
Value: :4.5stars:

Nu-Force uDAC2 and NE-700X Review

About NuForce:
Based in Milpitas, California, Nuforce first gained visibility for its patented Class-D power amplifiers, earning numerous awards from audio publications in the US and Japan.

Building upon its reputation as a company that developed state-of-the-art audio products, Nuforce worked diligently to expand its product line with digital-to-analog converters, in-ear and over-the-ear headphones, speakers and subwoofers, cables, additional home and headphone amplifiers and other audio accessories. Today, Nuforce is sold internationally and remains firmly committed to being a high performance consumer electronics company adhering to stringent quality standards, ensuring integrity and value in every Nuforce product.

Setup, Finish and Build Quality: (uDAC2):
Setup is a breeze on both PC and Mac with default drivers loading on both operating systems. Since the uDAC2 only supports up to a 96kHz sampling rate, there are no custom Windows drivers necessary. Of course I immediately noticed that the unit is substantially smaller than the RAM AMP-20 that I recently reviewed and the look is much sleeker and by far the more attractive of the two. The case is metal and the unit overall feels very durable.

As for the NE-700X, what can I say; attach the ear tips that feel most comfortable to you and plug it in. I did some quick comparisons, actually there was no comparison, to my inexpensive JVC HA-FX35AN ear-buds and the sound was night and day. The NE-700X output much more bass and were considerably more comfortable which is what I would expect considering the difference in price. The casing for the drivers are machined aluminum and are a bit weighty when compared to the much less expensive JVC's which is what I would expect. The overall build quality seems very durable and not likely to just quit on you as do so many of the cheaper ear-bud sets out there.

Let me start by stressing that this review is entirely subjective and lacks any “bench work” with big expensive testing gear. With that being said; there was a substantial difference in the quality of sound coming out of uDAC2 when compared to the Amp-20. The overall fidelity sounds much cleaner and much more refined. One thing I did notice is that though the uDAC2 only supports up to 96kHz and 24-bit resolution, the AMP-20 only supports up to 48kHz and 16-bit resolution giving the uDAC2 a noticeably improved sound quality. Specifically I noticed a fuller presence of sound coming from the NuForce unit. When compared to the uDAC2, the AMP-20 sounded thin and hollow and lacked the more pronounced imaging that came through with the NuForce unit. So with the basics out of the way, let us move on the published specs.

Published Specs:

  • Driver Size: 8mm
  • Impedance: 16 Ohms
  • Frequency Response: 20 to 20kHz
  • Rated Power: 3m W
  • Max. Input Power: 10m W
  • Sensitivity: 105 dB+/-3dB
  • Plug: 3.5mm
  • Connector Specification: 3.5mm 4-pole stereo/iPhone compatible plug
  • Weight (without packing): 15.4 grams
  • Length: 54 inches
  • Package Contents Include
  • Stereo headset
  • 3 pairs of single flange ear-tips (2 small, 2 medium, 2 large)
  • Carrying case

  • USB (USB 1.1, 2.0 compatible)
  • USB DAC: USB 1.1, 2.0 compatible. USB native bit rate: 32, 44.1, 48, and 96 kHz, 24-bit
  • Maximum sampling rate: 96kHz
  • Resolution: 24-bits

  • Analog RCA Output = 2Vrms
  • Dynamic Range: 90dB
  • S/N Ratio: 98dB
  • THD+N 0.05%
  • Digital Output: coaxial RCA 75-ohm
  • Headphone output jack
  • Power output: 80mW x 2 @ 16-Ohm
  • Headphone impedance 16-300 Ohm
  • 20-20kHz
  • USB Bus Powered, 80 mA/5V
  • Maximum power consumption: 500mW
  • 68x38x21mm

Included Accessories
  • USB cable (1 meter)

Reference Equipment:
  • Apple Mac-Mini
  • Audio Technica ATH500
  • Audyssey LES Speakers

Subjective Listening:
Here is where the rubber meets the road; well, sort of. I am in the process of retraining my ears to identify inaccuracies in sound reproduction through headphones and ear-buds, which for me is at best a little like learning to speak the Queen’s English after being born and bred in Texas; I can get to where I am going but there is a lot more effort involved. You see I have a lot of experience in sound engineering via multi-track and professional studio recording and I have a trained ear for the way things should be properly mixed and reproduction of sound through multi-channel speaker systems. However, that is a bit different than trying to pinpoint exactly what the intended result of a recording was through a couple of speakers strapped to your head or inserted in your ear and being able to identify whether or not if what I am hearing is an accurate reproduction of what the engineers and musicians intended, but I am going to give it my best shot.

I wanted to step outside of my comfort zone and queue up some new music that I might not normally defer to for my testing. During this process I flipped between using the uDAC2 and the AMP-20 through the NE-700X, the JVC HA-FX35AN and the ATH500 headphones. I also compared both DAC’s using my awesome new Audyssey LSE (Lower East Side) speakers and throughout my listening experience there were three constents.

  1. The uDAC2 always outperformed the AMP-20 with regards to sound clarity and fidelity.
  2. The NE-700X preformed outperformed the JVC HA-FX35AN.
  3. The ATH500 headphones always sounded cleaner, richer and more dynamic compared to the ear-buds.

Dream Theater: A Change of SeasonsDT’s twenty-three minute opus is just the type of song that someone can truly get lost in when it is properly presented. This isn’t the type of song that is really three or four songs patched together by a series of dangling notes or abrupt changes in order to transition, this is one long twenty-three minute song and is, IMO of course, hands down the greatest progressive hard rock song of all time. When I listened to A Change of Seasons through the uDAC2 using the NE-700X, I couldn’t help but be drawn into the sonic bliss of it. All of the time changes, tonal and key changes resonated through me and drew me in at every turn. This was an emotional experience for me and I was sorry it had to end. I will mention that when compared to the AT500's, the NE-700X did falter on the lower and mid-range bass but that is the difference between ear-buds VS headphones.

Frank Zappa: Joe’s Garage Acts 1-3
When I get into a real listening mood and I mean the kind of mood that I just want to tune everything around me out, there is normally no better listening for me than Frank Zappa's Joe’s Garage Acts 1-3. Zappa was one of the greatest musicians I have ever heard and clocking in at just over an hour and fifty-five minutes, Joe’s Garage has just about everything but the kitchen sink. When listening through the NE-700X, I did find that I tired of the ear buds after about an hour and moved on to the ATH500’s. That was really more of a comfort thing though and not because I felt I was missing out on anything. That being said, I realized after I put the ATH500’s on that I was even more immersed into Zappa’s opera than when I had been listening through the NE-700X. The music just felt “bigger” and more encompassing but that isn’t necessarily a knock on the NE-700X as much as it was a demonstration of the ATH500’s sound quality and another comparison between ear-buds and headphones. I have never listened to Joe’s Garage as intensely and as intently as I did on this day. Even though I have heard it in its entirety a hundred of times before, I just could not stop listening.

Now I was faced with a different problem. How do I follow that? The answer is that I don’t. There was nothing for me to put in and listen to through the headphones and ear-buds that I felt would yield different results. After nearly two and a half hours of solid engaged listening I realized that the uDAC2 and NE-700X had done what they were supposed to do, they made me WANT TO listen more and more.

As far as subjective listening through the Audyssey speakers, I noticed a minor loss in bass reproduction as compared to directly into my Mac on board sound. The sound overall using the LSE’s through the uDAC2 felt a little less engaging when compared to the ATH500’s and the NE-700X, but this was really more of a matter of distraction. When listening through the headphones, you are free to close your eyes and really experience the music as to where with speakers on your desktop you are much more easily distracted. This isn’t a negative for the LSE’s either, it’s just a matter of circumstance.

If there is one thing that I have taken away from this review, it is that I have started to re-think the way I listen to music. There was a lot that I did not understand when I reviewed the RAM AMP-20 a little over a month ago that was not unlike my misunderstandings of speakers when I really started to pay attention to the sound quality. After the RAM review, a friend of mine on the forum helped me understand that I was making a similar mistake in that I was equating different to better and that I needed to refocus my efforts to better differentiate between the two. This time I made sure to better identify the differences between the two devices I was listening to. For example, I noticed that the AMP-20 had more audible distortion and caused a certain amount of break down in the overall fidelity when compared to the uDAC2 at high volumes. Additionally, I noticed that the highs came across less penetrative and the mid-bass sounded muddy when compared to the uDAC2.

After all of the listening and comparisons, I am far from believing that the uDAC2 is the be-all end-all of portable DAC’s but the same can be said for just about any piece of equipment that I own. On the one hand, I have never known such an immersive experience using headphones in my life and that is a fact. That being said, I have never really went out to find such an experience either and I am a little hesitant at this point to concede that this is the one device for all of my needs. It really comes down to a matter of value. Do I think the uDAC2 is worth the price? Or put another way, would I pay $129 for that experience again? The answer to that question is unquestionably YES! That doesn’t mean that there may or may not be better devices for less. That doesn’t mean that there aren’t other manufacturers that make a better product. It simply means that I would pay the $129 MSRP to have that quality of sound available to me 24/7. Now if we can only get FIIO Recommended!

As far as the NE-700X ear-buds go; I thought that they had a very solid build quality and far superior sound to the JVC's I have been using at the gym and now use them at my office instead of the JVC's. However they do fall short of the Audio Technica AT500's overall sound quality. If you are looking for a great sounding pair of ear-buds for the gym, office or for your portable media player then look no further. If you are looking for audiophile sound quality for easing back in a chair and tuning the world out then there is still no comparison for a good set of "cans". Recommended!

3,697 Posts
Dale, thank you for the informative and detailed review. :T

Equating a difference as "better" often happens, glad you recognize the distinction. As one musician to another, I say listen for tone and timbre.

Someday I would like to get back into headphone listening. Headphones offer the lowest distortion listening experience by virtue of low driver excursion and the elimination of room acoustics.

1,747 Posts
Equating a difference as "better" often happens, glad you recognize the distinction. As one musician to another, I say listen for tone and timbre.

In particular, I think something that can play french horns correctly, is extremely good.

43 Posts
Nice review and thanks for the subjective disclaimer. Which ATH-500's? The ATH-A500 (64Ω/53mm), PRO500 (38Ω/40mm) or AD500 (66Ω/53mm) Open-Air's? Keep in mind open back headphones do suffer from room loading so don't sit to close to any walls when wearing open back phones. This is not opinion, btw, it is a fact that is not disputed in the real engineering world.

Now, the headphones you used were designed to have a source impedance of 0Ω. You will get sub-optimal performance from HPA's that have a higher output impedance when using LowZ ear bud/IEM's like your JVC HA-FX35N units or the NuForce NE-700X (both 16Ω). Not only is a near zero to zero ohms output impedance needed but also the current delivery into those loads. With only USB power, the uDAC-2 will stress over those impedances and current requirements. With a 6Ω output impedance, I would not use it with less than 50Ω headphones. The uDAC-2 would need a <2Ω Z-Out to not interfere with you JVC's or even their own NE-700X's. In other words, your JVC's and even their own NE-700X will have severe frequency response errors when used with the 3.5mm output. A better test of their own NE-700X would be to use it with a different HPA (one with a much lower Z-Out) so you can hear the phones own sound output instead of the voltage following the impedance and affecting it's FR. This is why amplifiers need to be constant voltage sources and all modern home/pro amps are designed to be a near perfect voltage source so they do not interfere with the basic FR of the loudspeaker. Home amplifiers accomplish this feat easily, HPA's need to follow this also. It is Basic Engineering 101stuff.

On a different note, make sure your Audio MIDI Setup in your iMac/Mac Mini/MacBook is set for 96kHz/24bit. If not, you are not getting 24bit audio no matter what you are connected to. Also make sure your source files are suitably high resolution so you are not resampling the audio. Here is a good article on computer audio and one that deals with 24bit resolution from Apple® iTunes or Windows® Media Player.



Again, thanks for a good review and I wish you well on your journey to "audio nirvana". Cheers! :T

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