You are here

Log in or register to post comments
satkinsn
satkinsn's picture
Offline
Last seen: 2 years 4 months ago
Joined: Aug 19 2008 - 4:23am
usb not ready for prime time?

There's a section in a competing audio publication this month dealing with USB DACs - the conclusion of the lead author is USB is simply not ready for prime time.

In particular, he argues the sound of USB pales in comparison to s/pdif.

I'm curious; what's been your experience?

Scott A.

note to mods: I assume mentioning a competing publication in this context is ok. If not, please let me know.

tks

s.

hikejohn
hikejohn's picture
Offline
Last seen: Never ago
Joined: Jan 20 2009 - 7:24pm
Re: usb not ready for prime time?

I read that article in TAS...as I recall he annointed SPDIF as the best...mmm, first time I have ever heard that. I do think that Charles Hansen of Ayre and Gordon Rankin of Wavelength...I have also heard that often from guys who should know. Whenever I compared USB to Digital to SPDIF...SPDIF came out on the bottom...Digital much better to me...but I have been listening to USB/DAV devices...to me clearly the USB will be better than SPDIF...

It would be interesting to have a technical comparison between the two interfaces....as I understood...and its perhaps what I heard SPDIF introduces more jitter...but I would love to learn more about this topic.

Editor
Editor's picture
Offline
Last seen: 3 years 9 months ago
Joined: Sep 1 2005 - 8:56am
Re: usb not ready for prime time?


Quote:
I read that article in TAS...as I recall he annointed SPDIF as the best...mmm, first time I have ever heard that. I do think that Charles Hansen of Ayre and Gordon Rankin of Wavelength...I have also heard that often from guys who should know. Whenever I compared USB to Digital to SPDIF...SPDIF came out on the bottom...

I haven't seen that article, but if you look at the measurements sections in Stereophile's reviews of USB-interface DACs, S/PDIF generally performs with lower jitter (depending on the quality of the data-receiver circuit). See, for example, http://stereophile.com/digitalprocessors/cambridge_audio_azur_dacmagic_da_converter/index2.html . This is because, as conventionally used, the USB interface only averages to the correct sample rate over a fairly long time period. In the short term, the sample rate can be different, which is by definition, jitter.

One exception is the Benchmark DAC 1 usb, which follows the USB receiver chip with a sample-rate converter; see http://www.stereophile.com/digitalprocessors/108bench/index6.html .


Quote:
It would be interesting to have a technical comparison between the two interfaces....as I understood...and its perhaps what I heard SPDIF introduces more jitter...but I would love to learn more about this topic.

The measurements sidebar in the dCS Scarlatti review in the forthcoming August issue (p.67) includes jitter comparisons between Toslink S/PDIF and USB, though the dCS's USB input operates in the same asynchronous mode as the Wavelength Cosecant - see http://www.stereophile.com/digitalprocessors/wavelength_cosecant_v3_usb_digitalanalog_converter/ .

John Atkinson
Editor, Stereophile

rlodad
rlodad's picture
Offline
Last seen: Never ago
Joined: Oct 17 2007 - 5:16am
Re: usb not ready for prime time?

Mr. Atkinson,
You should read the articles in the 8/09 TAS by Alan Taffel. I will send you my copy, as it is making me sick. It will help you sleep better at night when you realize they have a writer who knows nothing-zero-ziltch about his subject matter. There couldn't be a person on earth who has spent 3 minutes on Computer Audiophile.com who knows less about computer audio than Mr. Taffel. There is a review on the USB interface in general, and one comparing mid-end USB DACs S/PDIF inputs vs. the same units USB interface. Neither a single well known USB DAC nor a USB only DAC (Wavelength, Ayre) was listened to or reviewed. If you haven't heard about this yet, you will. It has exploded on forums on Audiogon, AA, Computer audiophile and others. It will make any gen x or y'er who is limited to an ipod now think that the only route they had to better sound, i.e. their computer, is useless. The audiophile community can afford neither such lack of logic from Mr. Taffel, nor such lack of editorial ability from Mr. Harley. Congratulations- you win! And we all lose.

rlodad
rlodad's picture
Offline
Last seen: Never ago
Joined: Oct 17 2007 - 5:16am
Re: usb not ready for prime time?

Just to pick nits,
DCS does not use the same asynchronous mode as wavelength as they do not license it from Gordon Rankin as Charlie Hansen does. DCS uses AN asynchronous mode, which I believe they developed.

satkinsn
satkinsn's picture
Offline
Last seen: 2 years 4 months ago
Joined: Aug 19 2008 - 4:23am
Re: usb not ready for prime time?

I don't care as much about the writer as the underlying point: when I started to pay attention to audio a couple of years ago, the single thing that excited me most was the idea that computers + USB would let me have an audiophile set-up, at a fraction of traditional audiophile prices.

Does that premise hold? Or is there, sadly, once again no free lunch?

Scott A.
Watertown NY

btw - I'm cross posting this note over at CA as well, because the readerships are somewhat different and I really do think this question is important.

linden518
linden518's picture
Offline
Last seen: Never ago
Joined: Dec 12 2007 - 5:34am
Re: usb not ready for prime time?

Scott, there is a new crop of USB DACs that let the DAC control the data & the attendant jitter issue instead of the computer. These are the 'asynchronous' models that have been written about in Stereophile (Wavelength Cosecant & dCS) and elsewhere (the upcoming Ayre USB DAC). I've also heard nothing but praise regarding the Weiss Minerva, which does the same thing but with Firewire. I have a Paradisea USB DAC, which is not as fancy as these DACs, but nonetheless, it sounds awesome via USB connection.

I really think people spending $10K+ on digital right aren't playing the hands right if they're looking for PC-fi option rather than the traditional transport/DAC option; great digital could be had for much less money, and it can only get better.

linden518
linden518's picture
Offline
Last seen: Never ago
Joined: Dec 12 2007 - 5:34am
Re: usb not ready for prime time?

I saw this reply from Gordon Rankin of Wavelength himself, on the CA forums:


Quote:
Gang,

I pulled out after talking to Alan and feeling he had no right to do a review like this because he had no understanding of the topic and had such sub par hardware that I could see nothing more than an Absolute Train Wreck.

TAS said he was the computer go to guy. When I talked to him on the phone he had never even done ANY computer audio.

What surprises me is why didn't other companies request their hardware back like I did????

Thanks
Gordon


Jee-zus. So TAS referred Gordon Rankin to Taffel as the computer guy, only to have it revealed that Taffel had NO experience with PC-fi!?! Obviously, Mr. Rankin did the sensible thing in demanding for his product to be returned to him before damage could be done, but like he says, looks like some manufacturers did not wise up.

Check the following link for Alan Taffel's response & Gordon Rankin's rebuttal:

http://www.computeraudiophile.com/content/State-USB-Audio-Alan-Taffel

Editor
Editor's picture
Offline
Last seen: 3 years 9 months ago
Joined: Sep 1 2005 - 8:56am
Re: usb not ready for prime time?


Quote:
I don't care as much about the writer as the underlying point: when I started to pay attention to audio a couple of years ago, the single thing that excited me most was the idea that computers + USB would let me have an audiophile set-up, at a fraction of traditional audiophile prices.

Does that premise hold? Or is there, sadly, once again no free lunch?

Sorry for the tardy response, Scott. I am sorry to confirm that there is no such thing as a free lunch. The USB Standard wasn't conceived with streaming high-quality audio in mind, so DACs using conventional USB receivers feature high jitter.

The Benchmark DAC 1 gets around that problem by using a sample-rate converter chip but the true solution is to emulate what happens in a FireWire link, which is to slave the PC to the DAC, which is to operate the USB link in asynchronous mode. As I said above, the latest DACs from Wavelength, Ayre, and dCS work in this manner, with a drastic reduction in jitter - see, for example, fig.13 at http://www.stereophile.com/digitalproces...ter/index5.html . Unfortunately, none of these products are cheap enough to be regarded as a "free lunch."

The Wavelength Cosecant was reviewed in July, the dCS Scarlatti USB DAC is reviewed in our August issue, and the Ayre QB-9 USB DAC in our October issue.

The EMu 0404, which uses a driver program on the host PC, costs $199 and has been claimed to offer low jitter, but I didn't find that to be the case - see http://www.stereophile.com/digitalprocessors/bel_canto_usb_link_2496_usb-spdif_converter/index4.html . However, the $99 M-Audio Transit USB, which I also tested in the Bel Canto review and which also uses a driver program, did offer relatively low jitter (though still an order of magnitude greater than the asynchronous USB DACs). It is cheap enough that I recommend buying one just to see how it performs in your system, to set a sonic benchmark.

John Atkinson
Editor, Stereophile

Editor
Editor's picture
Offline
Last seen: 3 years 9 months ago
Joined: Sep 1 2005 - 8:56am
Re: usb not ready for prime time?


Quote:
So TAS referred Gordon Rankin to Taffel as the computer guy, only to have it revealed that Taffel had NO experience with PC-fi!?! Obviously, Mr. Rankin did the sensible thing in demanding for his product to be returned to him before damage could be done, but like he says, looks like some manufacturers did not wise up.

I have mixed feeling about this. Stereophile's policy is to proceed with the review once the product has been received. But that in turn implies the responsibility of the magazine and its editor to ensure that the reviewer have the appropriate skill set and experience to be able to perform a fair review.


Quote:
Check the following link for Alan Taffel's response & Gordon Rankin's rebuttal:

http://www.computeraudiophile.com/content/State-USB-Audio-Alan-Taffel

Thanks self-divider.

John Atkinson
Editor, Stereophile

satkinsn
satkinsn's picture
Offline
Last seen: 2 years 4 months ago
Joined: Aug 19 2008 - 4:23am
Re: usb not ready for prime time?

John -

Thanks.

In light of your note, do you folks have any plans to review the Musicstreamer/Musicstreamer +?

More broadly, while I've got your ear, I want you to know how important your budget component listing is to me. I don't see myself as ever spending upwards of a thousand dollars on a component - which means, I know, that I'll miss a lot.

But thanks to you folks, I've found great, great pleasure at the low end. Please keep some of your writing for those of us who measure our spending in $10s and $100s.

Best,

Scott A.

Lick-T
Lick-T's picture
Offline
Last seen: Never ago
Joined: May 14 2006 - 8:04pm
Re: usb not ready for prime time?


Quote:
However, the $99 M-Audio Transit USB, which I also tested in the Bel Canto review and which also uses a driver program, did offer relatively low jitter (though still an order of magnitude greater than the asynchronous USB DACs). It is cheap enough that I recommend buying one just to see how it performs in your system, to set a sonic benchmark.

I own an M Audio Transit and it worked and sounded great on my old XP based laptop, especially when you consider the price. When I switched to a Vista based laptop, I could not get the beta drivers for the Transit to work without seeing the dreaded "blue screen of death." If you are a Vista person, beware - the drivers may not work even if M Audio says they will. I know, I know, I shouldn't be a Vista person...

To get hi-rez files off my laptop and on to my Benchmark DAC1 I bought an M Audio Fast Track ultra, which not only allows high rez playback, but I can record through it as well. Its worked great. In fact I've used this to digitize LP's to to 24bit, 882khz files to great result using Sony Soundforge.

Editor
Editor's picture
Offline
Last seen: 3 years 9 months ago
Joined: Sep 1 2005 - 8:56am
Re: usb not ready for prime time?


Quote:
In light of your note, do you folks have any plans to review the Musicstreamer/Musicstreamer +?

Yes, we had some internal confusion about who was going to review these products, but I have now received samples and will be writing about them in the fall.

John Atkinson
Editor, Stereophile

scottgardner
scottgardner's picture
Offline
Last seen: Never ago
Joined: Apr 11 2008 - 11:35pm
Re: usb not ready for prime time?

John,

I'm a fan of RME gear and I believe you use one of their pieces as a reference in some of your tests.

Are you aware that they will be releasing a USB version of their Fireface 400 called the Fireface UC? Do you think this piece will ever be reviewed by Stereophile?

It's not pretty to the avg consumer or audiophile but for a computer based theater system it will be a beautiful fit.

audioengr
audioengr's picture
Offline
Last seen: 2 months 1 week ago
Joined: Sep 23 2008 - 6:17pm
Re: usb not ready for prime time?

IMO, it was not the reviewers results that were so surprising given the system, but his conclusions that were inappropriate.

The conclusions should have emphasized "these particular S/W packages driving these particular devices using this particular computer with this OS etc.", rather than concluding that USB was not competitive yet with S/PDIF from a CD player, which is complete nonsense IMO.

It is up to the manufacturers to insure that the computers, rippers and playback programs are up to snuff for these reviews. There are such a wide variety of these elements, that very inconsistent results can happen. There is no way that I would stand-by while a reviewer used inferior S/W packages and computer to review my products. It's like sending a high-end turntable, and tonearm and having the reviewer use a really inexpensive turntable preamp, cartridge and cables. If you want a good result and a fair review, you provide these things, or at least insure that the reviewer has them.

I am a strong believer in "separates" for computer audio rather than integrated "servers". This gives the consumer a continuous upgrade path for playback software, computer OS, rippers, formats and other variables that they do not have control of with an integrated server.

The downside of this is that the consumer must stay informed of the latest developments in all of these S/W pieces. Fortunately, there is instantaneous communication now with the Internet, so everyone should know when a new version of iTunes comes out etc. These are often inexpensive or free tweaks that improve sound quality for the computer audio enthusiast.

Steve N.

struts
struts's picture
Offline
Last seen: 1 month 1 week ago
Joined: Feb 1 2007 - 12:02pm
Re: usb not ready for prime time?


Quote:
The USB Standard wasn't conceived with streaming high-quality audio in mind, so DACs using conventional USB receivers feature high jitter.


I disagree with the first part of this statement John. I would argue that the designers of the USB did anticipate the needs of streaming audio. Consider the following from

  • X
    Enter your Stereophile.com username.
    Enter the password that accompanies your username.
    Loading