NwAvGuy

You might also want to consider the HRT Music Streamer II. It has received some excellent reviews and offers some significant features not usually found in the $150 price range like a true isolated split-rail power supply and USB ground isolation (which solves the common ground loop problems when USB DACs are connected to other AC powered gear). Plus it's even designed and made in the USA which is kind of a miracle at that price. I haven't tested one yet, but I hope to. My guess is for anyone looking for an accurate and transparent DAC, it will easily rival a lot of much more expensive options.

Thanks Tyll and Rex. I'm sick of this shit too. I expected to be attacked by NuForce, but I didn't expect Head-Fi to act like some communist dictatorship and delete multiple posts of THEIR OTHER MEMBERS that stick up for me. So the whole Jude/Currawong bullshit argument of "it's only about him promoting his blog" falls apart right there. I have no idea what Jude's real reasons are, but it's gone well beyond just censoring links to my blog.

It's obviously a matter of opinion, but I think if I shared what has been said to me on HF, what I've been accused of, what's been done with my posts, what's been done with many other members posts who dared try and stick up for me, many would consider it "hostile". So I don't think it's a "lie" or "bullshitting" to use that word. Yes, the official reason given is the "blog promoting". But that policy is very inconsistently applied at Head-Fi and there's a lot of discretion going on. Hundreds (thousands?) of other HF users do the same thing. But they haven't come out against a HF sponsor as hard as I have. Hell, how many threads are on THIS forum about someone taking on a HF sponsor? This thread was started before I even joined here. It's apparently not an everyday occurrence. So is it such a stretch to think the same controversy might have also somehow influenced Jude's actions against me? Jude is certainly entitled to run his site how he chooses. But there are plenty of examples where he exercises considerable discretion in doing so. I'm one of those examples. I was "promoting my blog" in exactly the same ways with very similar HF threads about Cowon, Behringer, Sansa, and other topics but none of them are HF sponsors. And there wasn't a peep from any HF admins or moderators about any of those which came first. And Jude has flat lied in what he's posted to my blog. I have the screenshots to prove it. So if you want to call someone a liar, you might start with him. And the thing none of the HF admins, Jude included, have answered is what's wrong with directing people to my blog? Especially when I do it as "new window" link so anyone following the link isn't even leaving HF? To me it's no different than linking to a Wikipedia page as a reference. And, of my 145 posts on HF, only a few dozen have any links in them. So how does that qualify as my "primary purpose for being there" as Jude puts it when the other hundred plus posts in 40+ different threads don't even reference my blog? I'm not selling anything. I have no advertisers. Hits to my blog don't count for shit and I'm not pushing some weird religion or porn. So, really, why all the paranoia over linking to my blog when hundreds of other Head-Fiers are allowed to do the same thing? Please explain that to me?

Bingo. The trade-off buys a whopping 1 dB of dynamic range out of about 90 dB which is really questionable at best--especially when the NuForce is already plenty quiet for most. A few on HF accused NuForce of "taking the loudness wars to their hardware". I do agree the recordings that most expose the problem are more likely to already be in trouble to begin with. I found that out the hard way in my first listening test.

I'm a bit late to the party, but thanks for the link Grahame. I overlapped some of that era growing up so it was a nostalgic read in a good way. I would have agreed with Currawong and S&V several years ago, and perhaps it will still happen, but from what I've seen home theater is going in a different direction. Blu-Ray is capable of great audio, but few seem to care. Just look at how CES has changed since the 90's. The high-end exhibits get smaller, weirder, and more marginalized every year. While the main show floors have gone from having a few dozen sit down home theaters with decent audio systems to today's Android tablets, cell phones, and acres of flat screens. The cheap flat screen seems to be killing off most home theater. Typical buyers of 55" flat screens just get some crappy sounding 2.5" deep flat speakers to slap on the wall next to it. Today's serious theaters are more sold to the multi-million dollar McMansion crowd. A buddy designs six figure installations and the owners often make all the buying decisions based on pictures of the gear without ever listening, or viewing, anything. The dealer brings a 3 ring binder full of marketing brochures and a gallery of their past installations, and the whole deal is done at the dining room table. They're often more concerned about the fabric and leather swatches than the speakers. Obviously most wouldn't consider these folks audiophiles without ever listening to a single piece of gear before they drop $100K even if some of what they end up with has audiophile brand names on it. So times really have changed. I'm not sure what qualifies as an audiophile anymore?

For what it's worth, Virgin Mobile in the USA (Sprint) just came out with the LG Optimus a few weeks ago. It's a decent android 2.2 (Froyo) phone--especially if you like something that fits in most pockets. Sprint and T-Mobile sell essentially the same phone so there are lots of accessories already out for it. But the kicker is they have a $25/month plan with unlimited data, unlimited text, and 300 min talk time and no phone taxes and NO FREAKIN' CONTRACT. That's 1/3 or 1/4 the monthly price most I know are paying for their iPhones on a 2 year plan and still less than half the price of the closest competitor I know of. The phone is $150 which pays for itself in just a few months. The bad news is the headphone output isn't great--especially in terms of output level. You need efficient phones if you like it very loud. I suspect it meets the EU hearing protection regs. And I second the recommendation for the PowerAmp android app. It's the best music player I've found.

As Tyll said, output impedance is a complex topic. He knows more than I do about what headphone designers aim for. I've talked to several vendors at trade shows and, when I could find someone who even knew what I was talking about, they usually told me they design for "zero ohms" with their consumer headphones. I think this is because as balanced armature and multi-driver designs have become more popular, it's forced a lot of sources to lower their output impedance to deliver good sound with those headphones (i.e. partly the "iPod effect" Tyll mentioned). Even considering just conventional dynamic headphones (which usually have a relatively constant impedance with frequency) the damping changes significantly with different output impedances. As Tyll implied, the headphone designer has to balance the electrical vs mechanical damping. And it's a delicate balance if you want tight, clean, bass with deep LF extension. If you screw up that balance with the wrong output impedance, the quality of the bass gets worse. If it ends up over-damped the bass rolls off too soon and sounds weak. If it ends up under-damped you get an upper bass peak and lousy transient response making the headphones sound boomy with "flabby" bass. (EDIT: fixed "under" and "over" being swapped) I'm a fan of "zero ohm" output impedances for the reasons I've already mentioned. And I'm also a fan of more headphone designers aiming for that target. The more we get of both, the more the world will be a happier place. You can have your cake and eat it to. First, some of the better amps/dac/etc give you a choice of internal gain settings. This lets you better match the amp to high or low impedance cans. And a few companies let you select the output impedance as well. I'm surprised more haven't done so. That would let people experiment with what works best with their cans and their subjective tastes. You can find lots more in my article on this very subject: Headphone & Amp Impedance

No worries, I just wondered what the "bigger picture" was. I'm new here and VLSI layout isn't a common topic on audio forums. So I was just curious and wondered if I'd missed something.

Ah. In theory I agree a higher impedance load would have been good to add to the listening test mix. But as it was, it took a lot of time to put it all together, and many of the listeners didn't even bother with all the trials I offered. So adding more sets of files with different headphones wasn't really practical this time around. Based on similar assumptions, the tests also show the line outputs of the uDAC-2 sound pretty good. And the $29 Behringer gives the uDAC-2 a good run scoring similar or better in most areas. It also doesn't suffer from the well known channel balance problems, misleading specs, etc. I've readily admitted they were only informal listening tests not a rigorous full blown trial. My bench measurements, however, I fully stand behind. And there's just no real excuse for some of what I discovered. That said, I've also said many times on HF there are obviously plenty of happy uDAC-2 owners. And if they're happy, that's all that matters. It obviously works well enough for many people. I also think there are significant differences sample-to-sample (especially for channel balance). So some may have a better one than I tested. Like I said, my 8000 words wasn't all about the uDAC-2 itself. Much of it was about the rest of the story, NuForce, similar companies, etc.

I'm not sure what you mean? I listened to the NuForce, before I ever tested it, using HD590's, Denon D2000's, the SuperFi's and Mee M11+'s. All represent significantly different sounds and loads. When someone is deciding which amp or DAC to buy, if they can't try it with their personal headphones first, what they care most about is knowing how it's likely to perform with their headphones (or the headphones they plan to buy with it). If the amp or DAC has a relatively high output impedance, the answer is there's essentially no way to know. But if it has a low output impedance, it's a safe bet the amp will perform very similarly in terms of sound quality with any headphone they use it with. You can just about arc weld with the output of the Benchmark DAC1. It literally doesn't care what headphone you plug into it. It cheerfully delivers the same performance regardless. To me, that's the ideal. A higher output impedance, however, will change the sound with many headphones. And for some it might even change in ways that person likes. But that's entirely dependent on the particular headphone used. So if you rave about the uDAC-2 with say the Mee M11+ headphones (which are almost a constant 16 ohms). And I like your review so much I run out and buy one but I have UE SuperFi's, Shures, Etymotics, etc (which have widely varying impedances--very different than the M11's). I'm not going to be so thrilled with the uDAC-2. My lowly $29 Sansa Clip portable is likely to sound better. This is supported by all the people who didn't like the uDAC-2 in the listening test with the SuperFi's. It depends on what you mean by "affect the sound". If you mean different headphones sound different, yeah. But that's due to the headphones. I'm talking about reviewing sources, not headphones. I can assure you the Benchmark DAC1 Pre's "sound", for example, will NOT change in any audible way with different headphones. But yeah, my Denon's certainly sound different than my Sennheisers plugged into my DAC1. That's entirely because of the headphone and has nothing to do with the DAC1. It's, obviously, impossible to review every possible headphone with every possible source. So you have to do what you can to isolate the two from each other if you want to provide anything resembling meaningful reviews unless someone else is interested in the exact same combo you happen to review. Hmmm... thanks for subscribing. But if there have been updates, and you're not getting them, I'm at the mercy of Google there. Hopefully if there's a problem they'll fix it.

I wouldn't say 90% for electronics, but I would agree for speakers, headphones and a few other things. And sometimes, like you say, it's a matter of clever wording. Amplifier power specs got way out of hand a long time ago so the Federal Trade Commission stepped in and, for a long time, strictly regulated it. But that's no longer the case. But still, most manufactures make an attempt to have some element of truth to their specs--especially ones that are easily verified. Even cheap $200 A/V receivers usually have multiple power specs if you dig out the fine print with some of them actually being reproducible (usually with 2 channels operating rather than all 5 or 7). And some companies, like even Apple, provide very few useful audio specs. But NuForce was literally off by orders of magnitude with the uDAC-2. They claimed 0.0018% THD+N when the real number is 0.05%--about 27 times worse. And they made a similar huge cut to the dynamic range after my review was published. Both of those measurements are pretty black and white and easy to verify as standards exist for both. In my experience, most gear at least gets close to achieving the claimed specs in these areas. The usual exceptions are the little "boutique" audiophile companies like NuForce but even some of those do it right. It's also fun when a company makes say 3 versions of a similar product. And as you move up in price the specs get slightly better. But, in reality, all three measure the same (typically as good as the most expensive one). That's just pure marketing. And I don't mind so much if they make the cheaper versions look worse than reality.

Good point! That's a feature I'm not used to forums having so thanks for the suggestion. And thanks also to Tyll for the encouragement.

So, as the newbie here, I'm curious why you're needing/wanting to do a VLSI layout with open source tools? I wasn't sure of which of your nearly 4000 other posts might provide a clue?

Let me start by saying I agree with the above and many other posts in this thread. This is my first post here, and after reading this thread, I can see I've already had a rather mixed reception. As a general rule, anyone who's come out against the snake-oil side of the audiophile world hasn't fared very well or has otherwise been marginalized. The most obvious example is probably Peter Aczel and the Audio Critic. He had more people hating him than liking him. But, to my knowledge, the poor guy never said anything that was actually wrong. He was just trying to expose the truth which can be a rather thankless job in this business. And while I hope I'm not coming across like Jesus, if someone accused me of evangelizing objective measurements I'd probably have to plead guilty. These forums are filled with 98% subjective posts so, to me at least, there's plenty of room for a bit more of the objective side. I've been told Head-Case has lots of smart people and I don't see ads and links plastered everywhere for the products being discussed. So that's why I'm here. The admins at HF have become increasingly hostile over my saying bad things about one of their sponsors. I'm hoping to find more open minds here. Is that wishful thinking? Yeah, my NuForce review is by far the longest. But much of that is due to how NuForce responded before I even wrote it. Had they said just about anything other than (paraphrasing) "yup, the crappy measurements are correct, we designed it that way on purpose" I would have just reported the measurements, made some brief comments, and left it at that. The 8000 words are not so much about a $130 DAC, but about the company that designed it, how they've marketed it, and how they respond to having their product measured. The NuForce CDP-8 sells for $1500. CarlSiebert here asked the question "I wonder how it would sound if he had never measured it". I'm glad you asked! That's why I conducted a blind listening comparison of 3 DACs to find out. It's also why I listen to anything I'm going to review before I measure it. CarlSiebert went on to question the 0 dBFS clipping issue. As others here have pointed out, it's a valid concern. And a few even identified the NuForce distortion in the blind listening test. And even if you argue it's inaudible, it's not something I've ever seen in all the other devices I've measured. 0 dBFS is used as the reference signal to which many other tests are calibrated against. So it's something you have to run on just about any piece of digital gear you're testing. It's easy for a DAC to reproduce 0 dBFS without breaking a sweat let alone clipping. CarlSiebert said "The Beringer unit, according to Larry, sounds like ass. So it loses the war after winning all the bench tests. " Actually it faired pretty well in the blind listening test. And it didn't exactly win all the bench tests, only about half of them. The uDAC-2, for example, was quieter--both subjectively and objectively. Larry's sounded bad as he admits he used IEMs--exactly what the measurements would predict. Grawk said, "If the objective quantitative and repeatable measurements don't result in a better listening experience, what's the point?". If you look at how the listening test turned out, there is some good correlation between how things measure and how they sound. The high output impedance of the NuForce, when combined with IEMs, created flaws that were easily heard and strongly disliked. Larry's observation of the UCA202 could also be predicted from the measurements. Pars said, " ignoring things on a technical level shouldn't be tolerated either" and I agree. A "high-end" power amp fried my tweeters because of a really half baked current limiting scheme. The manufacture, much like NuForce, could only say "we designed it to sound great". That amp also didn't come close to meeting their published specs. I don't think anyone should have to put up with such sloppy designs that can cause real problems--especially when they're avoidable at zero cost to the sound quality or the manufacture. Grahame said, "would it sound better if they fixed those glaring technical problems?" and the answer is generally yes. He went on to say, "Why put up with fixable / avoidable glaring technical problems? If Beringer can avoid them for $29 it seems to imply that cost is not the issue in avoiding the problems? If you have a defined test regime, then you can apply the same tests ( + measurements) to different devices irrespective of the cost of the device, and compare them. In the absence of measurements, how do you get a (process/product) improvement feedback loop to make better stuff?" As Lord Kelvin said "If you can not measure it, you can not improve it." I think the above is all very true. But then I'm an engineer and we tend to think in these terms. Even companies like NuForce should either have a competent engineer or hire the services of one. So some of their mistakes are hard to dismiss. Atothex said, "I get a vibe that they wouldn't have done anything if they never got called out" And that's another reason for my 8000 words. Does anyone here remember the early days of "Secrets of Home Theater" when it was one guy testing DVD players? He'd write these really long detailed reviews of any DVD player he could get his hands on. He'd find $200 players that did most everything right and $2000 players that got far too much wrong--geeky stuff like how they handled various flags, 3:2 pulldown,etc. Lots of people were blindly buying those $2000 DVD players and "accepting" all the visible problems in their movies until he came along and exposed all the problems. Over the following years, even the huge manufactures had to start paying attention because little companies like Oppo were among the first to pass all his tests. It really can make a difference to call out the manufactures who are getting it wrong. Shouldn't someone keep the low volume guys honest? Headphone addict said, "I agree that a higher output impedance can sometimes make a difference in the sound but not always" and this is true. With balanced armature IEMs even the NuForce's 6 ohms is enough to cause audible problems. It scored an epic FAIL in the blind listening test when used with IEMs for just this reason. And I show the graph of the response which makes it pretty obvious why. To Failes, I listen with all sorts of headphones but some of the best in-ear types are balanced armature designs--Shure, Etymotic, UE, and many others. So what's wrong with explaining what happens if someone wants to use them? Yeah I do have ideas on how gear should be designed--mostly basic engineering 101 stuff. I'm fine with gear that's tweaked in a way to deliver a predictable "signature" or "sound" (say a soft high-end or whatever). But the problem with any output impedance over 2 ohms is you get an unpredictable sound that varies widely with different headphones. What benefit is that to the Average Joe reading reviews online? Yeah, if you can even find a retail brick-and-mortar audio store with all the gear you want available for demo, and they let you try enough different combinations, you might find some combo that's "synergistic", but how realistic is that? To Elnero, please see above. I'd say anything under about 8 ohms is (marginally) acceptable with conventional dynamic headphones. Under 2 ohms is best for balanced armature, multiple driver, or other more esoteric cans. There are more examples on my blog such as this one which shows the Behringer with it's original 50 ohms and after being modified at around 2 ohms (note the 14 dB of total deviation for the original): All of the above is my attempt to "catch up" here. I'm happy to answer questions, or whatever. Here's the link to the listening test results I mentioned above: DAC Listening Challenge Results