TAS 194: The State of USB Audio
September 6th, 2009 -- by default
Source: The Absolute Sound
Source: The Absolute Sound
Q: How does USB sound?
A: I regret having to report that, at this stage in its development, USB does not rise to the level of an audiophile-quality interface. With carefully chosen equipment and accessories, USB can sound perfectly pleasant. At the other end of the quality spectrum, it is nearly unlistenable. To one degree or another, though, the interface consistently exhibits a distinct sonic signature characterized by three negative attributes.
First, USB sounds synthetic. Instruments are cardboard-flat, lack substance, and have a distinct “plastic” quality. In this respect, the interface is remarkably reminiscent of TosLink. USB’s second primary attribute is sloppy timing. Accordingly, would-be steady beats are only approximated, and rhythmic propulsion never materializes, all of which takes a major toll on musical engagement. Finally, USB tonality is pale and washed out, robbing instruments of both richness and distinctiveness. Under optimal circumstances, USB’s undernourished instruments can sound blandly agreeable; but they are never convincing. Strings suffer disproportionately; through this interface they are invariably shrill.
On track after track, device after device, these particular characteristics, though varying in degree of severity, proved constant. Nor is USB strong in other areas—imaging, bottom and top-end extension, dynamics—that could help compensate for its failings. Upon first hearing USB, you may well find its sound encouragingly acceptable. But listen longer. Over time, the interface’s artificiality, rhythmic imprecision, and lack of sonic substance become increasingly evident and unsatisfying.
Q: How does USB compare to S/PDIF?
A: There is no comparison. USB sounds much worse. All four of the DACs I tested support both USB and S/PDIF, making differentiating the interfaces a cinch. For each DAC, I compared the S/PDIF output of a good CD transport—as well as that of a budget CD player—to the USB output of a laptop, with both sources sending the same bits at the same rate (44.1/16) to the same DAC. In theory, if USB was at least as good an interface as coax S/PDIF, the PC would sound better thanks to its hard drive. Yet regardless of which DAC I used, that was never the case. USB was always a pale shadow of S/PDIF, due to the former’s tell-tale synthetic glaze, washed-out timbres, lackadaisical rhythms, and screechy strings. In contrast, S/PDIF—even when anchored by modest gear—is quite capable of a measured pace, faithful tonality, and fleshed-out instruments. (For a more detailed comparison between USB and S/PDIF, with examples, see my review of the Bel Canto and the Focusrite format converters by clicking here).
Q: Does the equation change at higher resolutions?
A: No. To answer this question, I used the custom-built PC since it natively supports both USB and S/PDIF at high bit-rates. Opposite the PC sat the Benchmark DAC1 Pre, the only DAC on hand that also supports high-resolution rates over both interfaces. The Benchmark was also a salutary choice because it incorporates the same top-quality USB input module as the Bel Canto USB Link 24/96, thus allowing USB to put its best foot forward. With this setup, I was once again able to play the same bits—this time more of them—from the same PC to the same DAC, varying only the interface. And once again I heard the identical differences between S/PDIF and USB that I had heard at lower resolution levels; that is, high-res USB was inferior to high-res coax S/PDIF, and in precisely the same ways.
Q: Do all USB DACs sound the same when playing USB?
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Comments
"Q: How does USB compare to S/PDIF?
A: There is no comparison. USB sounds much worse. All four of the DACs I tested support both USB and S/PDIF, making differentiating the interfaces a cinch. For each DAC, I compared the S/PDIF output of a good CD transport—as well as that of a budget CD player—to the USB output of a laptop, with both sources sending the same bits at the same rate (44.1/16) to the same DAC."
To be fair, this question should have read: "How does USB compare to S/PDIF" using this particular set of devices at this point in time"
IMO, jumping to generalized conclusions based on a small sample of products is like listening to 2 CD randomly selected players and declaring that all CD players sound harsh. There are other USB solutions out there and have been for many years that were not included in this shootout.
Alan! Full Steam Ahead!
How can you be staying the course with a reprint of this article when you have run aground with audio experts on so many fundamental points?
Is bad publicity better than nothing?
Alan,
The problem here is that you did not really prepare for the article. In the first place you are using totally outdated computers. From a background such as yours this just seems silly. Using a sub standard laptop, a totally outdated G series MAC... but here is the kicker... A Win2000 computer. Maybe you didn't read the fine print in the 2000 release notes but Win2000 is not even USB Class 1 compliant. Meaning it does not even support all the functionality required to reproduce audio.
I have had many reviewers use the same laptop Alan is using and said they could not even get 24/96 to operate. I even had one of these sent here and the USB port had error rates so high the output did not classify as MP3 quality.
Next Media Monkey... Alan come on it is a well known fact that Media Monkey is not even bit true.
Gang this is why I withdrew my Cosecant from this review. At the time Alan had never even used a computer for high end audio.
It just seems ashame from a magazine that totes Absolute Sound that they can't even get the basic needs of the computer right for this. Especially in an age were power cords are going for +$800 and he can't even spend that much for a decent computer to do the review with.
It would have been very easy and very appropriate to buy a maxed out Mini for about the same cost as the power cords he is using and merely dual boot the unit into Vista or OSX and have a stable platform and consistent for each operatiing system.
To the editors who I sent many emails before this train wreck occured and numerious afterwards.... I just throw up my hands.... what were you thinking????
Thanks
Gordon Rankin
Not here to plug my own products, just here because I believe in the technology and feel Absolute Sound did a total injustice to it.
Furthermore Taffel and perhaps even TAS have a beef to pick. There is no possibility IMHO, that Alan Taffel could write such an unscientific, biased article unless he was trying to boost sales for the "formerly mainstream" audio hardware manufacturers who support his rag. Have you seen a Wavelength or Ayre ad in TAS recently? No, TAS has refused to have an educated reviewer listen to and comment on asychronous USB Dacs. Notice how the Benchmark products which don't use Gordon Rankin's USB implementation, but are well reviewed nontheless, were panned by Taffel? He couldn't say they sounded good, it would blow the whole article to bits. (As if it could stand on its claims, anyhow). The fact is the newer, USB only DACs sound great. Many DACs that Taffel listened to, with SPDIF and USB inputs, sound poor through the USB inputs because they were placed as an afterthought. The ultimate responsibility here lies with Mr. Harley. This junk article should never have been printed. And to have Steven Stone print an article drooling on about the Music Streamer on the next page is more pathetic. Fact is, get your opinions at Computeraudiophile.com, Stereophile, your local dealer, audiosylum- anywhere but TAS.
Furthermore Taffel and perhaps even TAS have a beef to pick. There is no possibility IMHO, that Alan Taffel could write such an unscientific, biased article unless he was trying to boost sales for the "formerly mainstream" audio hardware manufacturers who support his rag. Have you seen a Wavelength or Ayre ad in TAS recently? No, TAS has refused to have an educated reviewer listen to and comment on asychronous USB Dacs. Notice how the Benchmark products which don't use Gordon Rankin's USB implementation, but are well reviewed nontheless, were panned by Taffel? He couldn't say they sounded good, it would blow the whole article to bits. (As if it could stand on its claims, anyhow). The fact is the newer, USB only DACs sound great. Many DACs that Taffel listened to, with SPDIF and USB inputs, sound poor through the USB inputs because they were placed as an afterthought. The ultimate responsibility here lies with Mr. Harley. This junk article should never have been printed. And to have Steven Stone print an article drooling on about the Music Streamer on the next page is more pathetic. Fact is, get your opinions at Computeraudiophile.com, Stereophile, your local dealer, audiosylum- anywhere but TAS.
I've spoken with several engineers who thoroughly understand USB and there should be nothing in USB, as a physical transport layer, that should affect audio quality. However, because I read this artical and tried a different setup with my system, I now know that for whatever reason, USB does affect quality. I have a PC running XP (in the basement with cable running through the floor so I don't hear the PC's fan and disc seeks) and iTunes. All of my CD are ripped to Apple lossless and I had been playing them via USB to a PS Audio DAC for the past two years. Before I purchased the PS Audio DAC I was using a CardDeluxe sound card. The PS Audio DAC via USB sounded so much better than the analog out of the CardDeluxe I kinda left it at that. I did do an experiment of plugging in a low end CD player (my good CD player was busted) to the DAC via coax, but the PC to USB to DAC sounded much, much better so I left it at that for the past two years. After reading this article I decide to try connecting the PS Audio DAC using a high end coax to the digital out of the CardDeluxe. OMG!! Night and Day. Immense improvement of clarity, soundstage, transients, frequency response...you name it...it all sounds better. Vocals, percussion, strings, everything. Its like I've never heard my CDs before.
I still don't understand why - USB physical layer? Window's USB audio-class driver? or what? But I sure do like it!!!
THANKS FOR WRITING THIS ARTICLE!
I've spoken with several engineers who thoroughly understand USB and there should be nothing in USB, as a physical transport layer, that should affect audio quality. However, because I read this artical and tried a different setup with my system, I now know that for whatever reason, USB does affect quality. I have a PC running XP (in the basement with cable running through the floor so I don't hear the PC's fan and disc seeks) and iTunes. All of my CD are ripped to Apple lossless and I had been playing them via USB to a PS Audio DAC for the past two years. Before I purchased the PS Audio DAC I was using a CardDeluxe sound card. The PS Audio DAC via USB sounded so much better than the analog out of the CardDeluxe I kinda left it at that. I did do an experiment of plugging in a low end CD player (my good CD player was busted) to the DAC via coax, but the PC to USB to DAC sounded much, much better so I left it at that for the past two years. After reading this article I decide to try connecting the PS Audio DAC using a high end coax to the digital out of the CardDeluxe. OMG!! Night and Day. Immense improvement of clarity, soundstage, transients, frequency response...you name it...it all sounds better. Vocals, percussion, strings, everything. Its like I've never heard my CDs before.
I still don't understand why - USB physical layer? Window's USB audio-class driver? or what? But I sure do like it!!!
THANKS FOR WRITING THIS ARTICLE!
Again, in computer to USB audio, quality depends on lots of factors in setup. If you got such a difference with the coax out of your sound card, then you probably needed some software or hardware tweaks to get comparable or better sound from USB. USB done right can sound as good or better than just about any soundcard output (even from COAX). But if you're happy with what you're doing now, that's all that matters for you.
I don't know your "engineer" acquaintances, but I'm willing to bet they have a computer and not a sound background. Computer people will tell you that there is nothing in USB that should affect sound. Audio people with USB experience will tell you that USB can sound great if you know how to use it and set it up for audio.
The problem with the above article is that the reviewer didn't know how to properly use USB for audio, and went on to conclude that "USB can't" give high level results.
I'm an oudiophile that is approaching the world of music on FLAC on hardrives and I'm reading as much as I can to get more info.
Well from all what I read in the previous comments we can assume that if on one hand the quality trhu SPDIF is a no brainer, on the other thru USB, unless the user has a solid foundation in informatic to implement all what it takes to have the USB the perform at it's best, the results are likely to be way below it's true potential and this is a serious issue that makes this technology not very user friendly so far. Is this correct?
It's not that simple. USB takes a little effort to learn the setup, but it's not rocket science.
See http://www.benchmarkmedia.com/wiki/index.php/Computer_Audio_Playback_-_S...
for the basics.
SPDIF is simple, but in many cases unless you have a pro level sound card like a Lynx, won't give sound at the level that properly setup USB will.
USB has some convenience factors in its favor also, once it is setup.
It's not that simple a dichotomy. USB takes a little effort to learn the setup, but it's not rocket science.
See http://www.benchmarkmedia.com/wiki/index.php/Computer_Audio_Playback_-_S...
for the basics - not hard to apply to any server.
SPDIF is simple, but in many cases (unless you have a pro level sound card like a Lynx), won't give sound at the level that properly setup USB will.
USB has some convenience factors in its favor also, once it is setup.