Do You Need To Use A USB TO S/PDIF Converter Instead of Direct USB?

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Bernard

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There are two schools of thought about how you should go about connecting a music source with a USB output to a DAC:

There is the Roberto school of thought that says you should go USB from your music source to a USB - S/PDIF converter (such as a Bel Canto RefLink), then S/PDIF to the DAC. This is because the Ref Link clears up jitter and other such crap. You should also not spend a pile of money on the DAC as improvements are coming out frequently.

Then there is the Bonzo school of thought that says forget the RefLink, and go direct USB from source to DAC. Spend the money you have saved in not buying the RefLink on a better DAC.

What do others think?

I hope I have represented correctly the views of Roberto and Bonzo expressed in another thread; gentlemen, please correct me if I have not.
 
I don't use either because I have a Squeezebox. :) But I would say it is eminently dependent on your DAC Bernard.

The USB interface's job is to take the data out of the computer and clock that data at the appropriate rate for the DACs to then convert. It's an important step in the chain. It is where computer data is becoming audio/music, and that step can either be built into your DAC or done separately. Bearing in mind though - many DACs also have buffering and jitter immunity/reduction on the S/PDIF input, which go various means of effectiveness at reducing the importance of the USB interface.

Exactly the same as saying "do you use a phono preamp or do you use the one in your preamp"? Answer: either can give good results depending on the quality of the one inside your preamp.

So I would not say Roberto has a "school of thought" so to speak - simply that in this instance, he prefers his specific Bel Canto USB interface over the one built inside the M-DAC.

So the same as most other things in audio - try both and see which you prefer. But bearing in mind that what might sound best with one DAC might not sound best with another DAC.
 
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Hi Bonzo school of thought is ranked no.1 in Businessweek for Economics and audiophilia

That said google the CAD dac founder's paper on optimizing your computer for USB. Generally by buying a ref link you keep your dac limited to the ref link quality. Ref link is required if your dac is not async, and very few of them are that way today. I also think you need to represent Justin here, if for no other reason than that he agrees with me on his point.


There are two schools of thought about how you should go about connecting a music source with a USB output to a DAC:

There is the Roberto school of thought that says you should go USB from your music source to a USB - S/PDIF converter (such as a Bel Canto RefLink), then S/PDIF to the DAC. This is because the Ref Link clears up jitter and other such crap. You should also not spend a pile of money on the DAC as improvements are coming out frequently.

Then there is the Bonzo school of thought that says forget the RefLink, and go direct USB from source to DAC. Spend the money you have saved in not buying the RefLink on a better DAC.

What do others think?

I hope I have represented correctly the views of Roberto and Bonzo expressed in another thread; gentlemen, please correct me if I have not.
 
Hi Bonzo school of thought is ranked no.1 in Businessweek for Economics and audiophilia

That said google the CAD dac founder's paper on optimizing your computer for USB. Generally by buying a ref link you keep your dac limited to the ref link quality. Ref link is required if your dac is not async, and very few of them are that way today. I also think you need to represent Justin here, if for no other reason than that he agrees with me on his point.
Justin is a big boy; he needs no help from me :devil:
 
Hola Chicos and Bernard, you got me here. I use the Reflink because I do believe that the junk sound that I get from FM Internet broadcast and Youtube are truly cleaned up by this device. Also, the sound quality is more organic, more spacious, more of what I am used to, from my cd transport. Also, my M-Dac does not support 192KHz via USB, only 96KHz, but it does. if I use coax or optical. I truly believe that the Reflink is doing a great job with my computer music. I had take away the Reflink from my system, and boy, I am truly now very be accustomed to it. Getting a better DAC than my M-DAC? Yes, but I just tried the new Exasound, a very interesting DSD DAC, not so expensive, and one next to the other, there are things that both do very nicely and others not so. So, right now, I am still at first base safe. Yes, on the other hand, Kevin has on his hand, a lot of nice toys to play with...and his conclusions perhaps could be mines too. But again, what I am getting, and what I am listening, and using quality recordings, my ears are happy, and I could say very happy. For those who have M-DACs, there is an upgrade for it. Here is the link:
http://mdac.referata.com/wiki/Main_Page

Happy listening!
 
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Ok, Bernard. Just for fun I will add one more: the Rich school of thought. I just got a good deal on the PS Audio PerfectWave Transport (aka memory player) and plan on purchasing the PS Audio DirectStream DAC with an integrated network card. This allows you to interface the DAC directly to your network via Ethernet. Check out this DAC if you haven't already. They have a great implementation to keep Jitter and noise down while maximizing the signal. Very simple signal path compared to traditional DACs. Very cool. I can't wait to get it all in place. Until I buy the DSD, I will use my Wadia as my DAC for the memory player (assuming I can figure out what is wrong with the Wadia and get it fixed).
 
Sounds like a cool idea. I don't like the devialet yet, but I really wish they improve on it so we get a cordless amp and dac in one place
 
...and thinking loud, I spent $ 2400.00 in the RefLink and the M-DAC, and still, with DACs costing twice this much, the sound that I am getting is very nice too...I am not saying that they do not sound right, what I am saying is that I have another good sound presentation, and have some money in my pocket. My ears are happy. I do know that yours are too. It is another way to go. Happy listening!
 
I used an MF VLink with the MF Tri-Vista and had no end of timing issues with it. Async USB is morer betterer than USB->SPDIF as the DAC issues and event or asynchronous callback to request the next batch of data from the PC. A USB to SPDIF link cannot do this. Therefore, the DAC can run a small data buffer, and clock the data in very nicely thank you, using its own internal clock.

Trust me - it is a better solution technically. Here's a more complete explanation why - a good one, I think. http://www.audiophilleo.com/definitions.aspx?Asynchronous%20USB

An Ethernet implementation like Rich's can do exactly the same thing I can safely say - having done loads of socket programming on various platforms over the years.
 
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Hm... I really think the man has gone nuts in that paper. I really don't think most of what he is suggesting will make one iota of difference if a decent async USB card and internal clock it present in the DAC.
 
Hm... I really think the man has gone nuts in that paper. I really don't think most of what he is suggesting will make one iota of difference if a decent async USB card and internal clock it present in the DAC.

+1.

Going on like that guy shows abject lack of understanding of how computers and data work. I mean "Windows 8 sounds better than Windows 7", and "having music and OS sharing a drive then sound quality will suffer"......what a joke!

Millions of petabytes of data are transmitted around the world every day.

And it's highly sensitive data like banking data, safety data, military secrets, commercial data and data we rely on to stay alive - aviation, water sanitation, electricity generation, etc.

In general - far more critical to get right than your version of Mahler Symphony 6 in A minor.

This sensitive data goes through water, cheap cables, telephone lines and satellite links, wireless networks, SANs and data centres.

The quality does not suffer. Then integrity of the data does not suffer.

And FFS - my banking records aren't more accurate because the bank ensures the OS and my account details are on different drives! Or because they are using Audioquest USB cables on the teller's desk. Or because they changed their switch-mode power supplies on their SAN for linear ones! Get outta here!

Getting data that happens (by chance) to be music from a computer to a DAC is no different. Getting it down a USB link is a trivial task.

Audiophiles need to understand that computer data and analogue audio are two entirely different beasts.
 
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As already mentioned Bernard, it does depend on the DAC. In addition to asynchronous mode operation, not all formats are supported on all inputs in every case. On the new DAC I've got inbound right now Toslink, S/PDIF and AES/EBU all support up to 24/192K, however only USB supports 32/352.8K, DSD64 and DSD128. Using a USB to S/PDIF converter would actually limit the capabilities of the device.
 
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If it's "jitter" that is the concern then, my opinion is, it doesn't matter what implementation is used so long as any jitter, like any type of distortion, is kept down to inaudible levels. These days that's a trivial task for most any decent USB implementation.
 
If it's "jitter" that is the concern then, my opinion is, it doesn't matter what implementation is used so long as any jitter, like any type of distortion, is kept down to inaudible levels. These days that's a trivial task for most any decent USB implementation.

It is not even that. Jitter does not exist (by definition) on an async USB connection.

asynchronous
əˈsɪŋkrənəs,eɪ-/
adjective 1. not existing or occurring within time.
 
Actually, Bernard, comments from some members on other forums suggest that different dacs respond differently - some do better on spdif and some do better on USB. USB needs laptop to be optimized, and some usb power (like the iFi usb (cheap)) to sound better. The Lampizator according to its founder sounds better on spdif hence his transport is made for spdif, and yes, I can confirm it sounds better, though I have no way of telling if it's because of the transport being better than my macbook or because of the the spdif input. That kind of implies your transport, cable, and dac will all play a role in deciding what sounds better
 
Kedar, so the answer to my original question is the same as the name of that famous hygiene product: "Depends"! :)
 
Actually, Bernard, comments from some members on other forums suggest that different dacs respond differently - some do better on spdif and some do better on USB. USB needs laptop to be optimized, and some usb power (like the iFi usb (cheap)) to sound better. The Lampizator according to its founder sounds better on spdif hence his transport is made for spdif, and yes, I can confirm it sounds better, though I have no way of telling if it's because of the transport being better than my macbook or because of the the spdif input. That kind of implies your transport, cable, and dac will all play a role in deciding what sounds better

I think the USB input sound a bit more relaxed than the SPDIF input on my Lampi but I might be imagining it. I probably am. The Lampi transport is a pretty crazy device, though, with its tubed SPDIF output.
 
Yeah so it's tough to say whether it sounds better because the transport is better than my unoptimized mac (which it is), or if the spdif itself is better than the USB. Lukasz (lampi founder) says the spdif sounds better, and he also says he doesn't know why
 

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