[129207]

Quote:

I just noticed this thread after someone reported a post.  Interesting stuff, but bear in mind one thing: the uDAC 2 is a $100 USB-powered DAC/amp, not a $1000 DAC with extensive power filtering, a dedicated amp and whatever else built in.  There are physical limits to what can be achieve with electronics and keep the price low. Expecting cheap gear to measure like expensive gear and you'll just be disappointed. While there is cheap audio gear that, on the surface (IE: if you use just RMAA) that appears to measure well, it very often sounds terrible.  It'

You're missing the point. He measured a $29 Behringer DAC that ended up having better results than the uDAC2. His whole blog is basically about not having to pay top dollar for equipment that's still solid. Read! 

 

[blackzarg]

It seems the matter has turned into the same old question of a newbie asking an "audiophile" "What settings should I have XXX at?", where someone is more worried about the measurements rather than real life performance. If it sounds good to people, who cares about the measurements? Most people like their music slightly warmer. I know a few people who run four subwoofers to get more sonic boom. Accurate? No. Above reference levels? Yes. Pleasing and exciting for them? Yes.

 

[nwavguy]

Quote:

I just noticed this thread after someone reported a post.  Interesting stuff, but bear in mind one thing: the uDAC 2 is a $100 USB-powered DAC/amp, not a $1000 DAC with extensive power filtering, a dedicated amp and whatever else built in.  There are physical limits to what can be achieve with electronics and keep the price low. Expecting cheap gear to measure like expensive gear and you'll just be disappointed.

As Negakinu said, the above is precisely why I compared the $129 uDAC-2 to the much less expensive $29 Behringer UCA202 USB DAC. The Behringer measures much better than the uDAC-2 in several areas despite the fact you could buy 4 of them and have money left over compared to the uDAC-2. So I wasn't at all disappointed in the Behringer, but I certainly was in the uDAC-2.
 
As to listening vs measuring, that's an endless debate. Head-fi prohibits discussing the specifics in this forum, but there are ways to do objective listening tests. And when those are properly done, the results are almost always very different from what most of the "listening matters most" crowd would expect. It's also been well documented why this is true. For those interested, please see the interesting links on the right hand side of my blog.
 
I have also offered a way for anyone to listen to the uDAC-2 vs the $29 Behringer and a much more expensive reference quality DAC on my blog.
 

 

[kostalex]

Let me ask a stupid question: do you hear how uDAC-2 clips?
I think it does matter. If you measured some clipping, and NuForce approved it, then the final question is - does anybody hear it?
This is how we can unite listening and measuring.

 

[nwavguy]

Quote:

Let me ask a stupid question: do you hear how uDAC-2 clips?
I think it does matter. If you measured some clipping, and NuForce approved it, then the final question is - does anybody hear it?
This is how we can unite listening and measuring.

You can listen to the files I posted for yourself. Clipping distortion is relatively easy for an A/D to capture and record. So the clipping should be present in the recordings available on my blog. I would encourage anyone who's interested to have a listen, and share what you think sounds best in one or both of these head-fi threads:
 
http://www.head-fi.org/forum/thread/542968/nuforce-udac-2-listening-challenge
 
http://www.head-fi.org/forum/thread/543279/3-headphone-dacs-listening-challenge-sequel

 

[kostalex]

Do you mean listening them on uDAC-2?

 

[nwavguy]

@Kostalex, You can listen to the test files on anything you like. Because the listening test is mainly about the differences between the recordings, not the absolute sound of any one recording, you don't need near-perfect gear to pick a favorite.
 
It's somewhat like looking at 3 different shirts at an online retailer. You can tell easily how they're different from each other by looking at the pictures of each shirt using your PC. You don't need a perfect computer display to tell that one might be a slightly darker shade of blue than another one. Most any computer display is good enough to show the differences. But you can't be sure of the exact shade of blue until you have the real shirt in front of you.
 
It's the same idea here. Your headphones and playback hardware don't have to be perfect to reveal the differences between the test files. But the more revealing your gear is, the more subtle differences may be more obvious.

 

[jasonl]

The DAC's output is re-sampled into a WAV file so how can this be the same as 'listen to the actual output from uDAC' after it's re-digitized ?
 

 

[holland]

Quote:

I just noticed this thread after someone reported a post.  Interesting stuff, but bear in mind one thing: the uDAC 2 is a $100 USB-powered DAC/amp, not a $1000 DAC with extensive power filtering, a dedicated amp and whatever else built in.  There are physical limits to what can be achieve with electronics and keep the price low. Expecting cheap gear to measure like expensive gear and you'll just be disappointed. While there is cheap audio gear that, on the surface (IE: if you use just RMAA) that appears to measure well, it very often sounds terrible.  It's quite funny for me to read months of subjective impressions of a product and even use it myself, then see someone post measurements that just confirm what I and others heard when we used it (though in that statement, I'm not referring to the uDAC, as I've never owned one).

 
Cost doesn't have any bearing in this.  It's the loudness war taken to the hardware design, really.  It's kind of sad, IMO, but understandable since the masses can't really discern clipping....with all the distortion in subwoofer thumping cars, and poor speakers, and headphones but not really listening, etc.  Whether or not it is acceptable is something different than understanding the reasons for it.
 
It's simply the analog gain stage for the DAC differential to single ended conversion is set too high, so it clips above -1.3dBFS (according to Nuforce).  It may not be noticeable in the majority of the population, but surely some ears will be able to.

 

[nwavguy]

Quote:

The DAC's output is re-sampled into a WAV file so how can this be the same as 'listen to the actual output from uDAC' after it's re-digitized ?
 

A better way to think of it is: "compare the actual outputs of the DACs". You are listening to what each of the them sound like relative to each other. Just as you would compare 3 photographs of something on a computer monitor. The computer monitor might make subtle changes to the colors, etc. but you can still discern a lot of differences between things.
 
It's also worth pointing out the A/D converters, and overall performance, of the Benchmark ADC1 are superior to those used to produce the original music most people listen to in the first place (i.e. studio A/D gear). So if the the typical studio converters, and 16 bit/44 Khz format are good enough to capture enough information in the voices and instruments we all listen to, one can argue it's also good enough to capture the differences between DACs. Especially if they're significant differences that are easily heard--like say the differences between two different guitars or pianos which are easily captured by "digitizing" at 16/44.
 
And if the differences are not easily heard, why spend lots more money for an expensive DAC?

 

[Tergie]

 
@Nwavguy, I'm sorry to be another one diverting from technical nature of this thread, but at this point I don't think it will do any harm. To be clear, I do find Jason's reactions to be rather personal than professional, rather defensive than constructive, and do not have enough knowledge nor reason to challenge the results of your measurements. I do not think you were arrogant or offensive, but rather single sided. I do miss one thing, the user's view (considering you bought one too, you are a user too). I see manufacturer's view, I see reviewer's view, but no proper user's view. There are some signs of it though in the very beginning of your review, where you state "I went back and forth a few times between the uDAC-2 and my Benchmark DAC1 Pre’s headphone output and didn’t notice any huge differences", this I find to be a major statement from user's point of view, but there is no mention about this later in the review nor the thread. Did you like the sound before you actually measured it? Surely the quantitative aspects are much more easily measurable thant the quality, but ultimately the quality is what matters the most, and I am not referring to quality of construction or design, but quality of listening experience.
 
Be aware that the people reading this have not just sensitive ears, but also sensitive minds. How does knowing that equipment I am using is technically inadequate affect my overall experience? It shouldn't matter, I know, but it does somehow to me. Actually, you are encouraging us to take our time to find the inadequacies ourselves, to deliberately find them. Why would I do that? Nothing is perfect and when you are looking for imperfections you will always find them.
 
I fully understand and appreciate your intention to clearly reveal the technical performance, but I believe that, while being interesting, does not matter to regular user that much. Am I supposed to really hear the inadequacies when using the equivalent headphones? I mean equivalent in terms of price, i.e. headphones for about 100$-200$?

 

[nwavguy]

 
Quote:

 
@Nwavguy, I'm sorry to be another one diverting from technical nature of this thread, but at this point I don't think it will do any harm. To be clear, I do find Jason's reactions to be rather personal than professional, rather defensive than constructive, and do not have enough knowledge nor reason to challenge the results of your measurements. I do not think you were arrogant or offensive, but rather single sided. I do miss one thing, the user's view (considering you bought one too, you are a user too). I see manufacturer's view, I see reviewer's view, but no proper user's view. There are some signs of it though in the very beginning of your review, where you state "I went back and forth a few times between the uDAC-2 and my Benchmark DAC1 Pre’s headphone output and didn’t notice any huge differences", this I find to be a major statement from user's point of view, but there is no mention about this later in the review nor the thread. Did you like the sound before you actually measured it? Surely the quantitative aspects are much more easily measurable thant the quality, but ultimately the quality is what matters the most, and I am not referring to quality of construction or design, but quality of listening experience.
 
Be aware that the people reading this have not just sensitive ears, but also sensitive minds. How does knowing that equipment I am using is technically inadequate affect my overall experience? It shouldn't matter, I know, but it does somehow to me. Actually, you are encouraging us to take our time to find the inadequacies ourselves, to deliberately find them. Why would I do that? Nothing is perfect and when you are looking for imperfections you will always find them.
 
I fully understand and appreciate your intention to clearly reveal the technical performance, but I believe that, while being interesting, does not matter to regular user that much. Am I supposed to really hear the inadequacies when using the equivalent headphones? I mean equivalent in terms of price, i.e. headphones for about 100$-200$?

To your question about my subjective opinions, I did talk more about that much later in the review (near the end) in the technical section. But the short answer is it really depends. With my Ultimate Ear headphones, for example, I clearly and easily prefer the sound of the Benchmark DAC1. And at really low volumes where the channel balance error is obviously audible, I also easily prefer the Benchmark. Those two things, alone, are "deal killers" for me. Even if I would not have taken a single measurement, they would still have me returning my uDAC-2 as many others have done. But with headphones that have a more forgiving impedance, and with the volume control turned up higher, the uDAC-2's flaws are less obvious.
 
There are lots of people here that seem quite happy with theirs, others not so much. There's already a massive thread here some 50 pages long of mostly subjective opinions about the uDAC-2. So I wanted to add something different, rather than more of the same.
 
To me, the sad thing is, the flaws could easily have been fixed at zero (or near zero) cost to NuForce. And then it would be a much better product with no excuses (or drama) required. And, in my opinion, it would be a better sounding, as well as a better measuring product. The two are in no way mutually exclusive as NuForce has sort of implied.
 
I'm really trying to only do two things with my review, and posts:
 
1 - Help people shopping for products make more informed decisions. If someone doesn't believe in measurements, objective testing, how companies do things, the measurements behind the sound, etc, they're certainly free to ignore what I've had to say.
 
2 - Help provide some incentive for manufactures to improve their products. One person really can make a difference. The now quite popular "Secrets of Home Theater" website ( http://www.hometheaterhifi.com/ ) started with one guy testing DVD players. He found that some $100 players outperformed many of the $1000 players. The very Oppo players that are now "cult favorites" got their first "fame" on that website. Over the years, manufactures were essentially forced, originally by his website, to start addressing the many problems their DVD players had. And it was really geeky stuff--some didn't support 3:2 pull down correctly, etc. Few even knew about those things until "Secrets" came along and started explaining the geeky stuff was why some movies didn't look very good, etc. And, in the end, it's made a huge difference in the DVD players (and now Blu-Ray players) you can buy today at much better prices. Even huge companies like Sony, Denon, etc. had to fix a lot of flaws exposed on that website. One guy, starting one website, raised awareness of a bunch of technical issues and it's had lasting changes for the better. So, while I'm not expecting to be the next "Secrets", hopefully others here can see my point.
 

 

[Tergie]

@Nwavguy, point taken, your findings should be really appreciated and contribute to improvement of the product and I am really curious how the NuForce will react, I mean with the adjustments of the uDAC design (though the channel balance has already been improved considerably against the first version, I own both).
 
I was just missing the complete "picture" which maybe was not your intention originally. I believe that despite the technical inadequacies, the uDAC does have sound qualities that should be appreciated and if it does, the message of the review shouldn't be just to return it because it is flawed and not worth the money.

 

[Currawong]

Quote:

As Negakinu said, the above is precisely why I compared the $129 uDAC-2 to the much less expensive $29 Behringer UCA202 USB DAC. The Behringer measures much better than the uDAC-2 in several areas despite the fact you could buy 4 of them and have money left over compared to the uDAC-2. So I wasn't at all disappointed in the Behringer, but I certainly was in the uDAC-2.
 
As to listening vs measuring, that's an endless debate. Head-fi prohibits discussing the specifics in this forum, but there are ways to do objective listening tests. And when those are properly done, the results are almost always very different from what most of the "listening matters most" crowd would expect. It's also been well documented why this is true. For those interested, please see the interesting links on the right hand side of my blog.
 
I have also offered a way for anyone to listen to the uDAC-2 vs the $29 Behringer and a much more expensive reference quality DAC on my blog.
 

I hadn't got to the bit about the Behringer when I posted (and most of my post was a general comment about attempts at introducing science on the forums).  I'm looking now though. Very interesting. The way you explain how the design relates to performance and what we hear in your articles I think is very good. 

 

 

[jasonl]

As I have mentioned, we will post a technical response, probably by tomorrow.
In response to one of the member's post, I got personal with the review not because of the technical interpretation of the measurement (which we will point out TECHNICALLY that it is flawed), but the way he distorted the communications between us. As he has said in the title, creating drama for the blog. If you want to discuss some technical merits, why go to such extend unless there is hidden agenda? What have we done to you? Just talk about the facts. Why do you have to imply that Nuforce in incompetent, lack of equipment etc? Why don't you go pick on Bose. Oh, that's right, Bose is known to buried anyone in lawsuit (win or not, they will bleed you financially to death) so nobody dare to touch them. We still don't know who you work for.
 
I urge everyone to be patient and read the technical response.