Ask AudioStream: USB or S/PDIF?

I recently bought a Wyred 4 Sound DAC1. I also have a Musical Fidelity V-Link.

Would you expect better performance with 16/44.1 files using the USB input or the coaxial RCA S/PDIF input (through the V-Link) on the DAC1?

Also, what are the relative merits of the coaxial RCA vs. TosLink S/PDIF inputs, assuming grounding is not a problem with RCA?


Hi Steve,

Thank you for asking AudioStream!

In theory there should be no audible difference between S/PDIF (TosLink or Coax) and Asynchronous USB connections as long as they are properly implemented. We're talking about passing a signal without sonic degradation and it can be argued that each offers a theoretical approach to do so.

In practice, when passing a digital signal from a computer to a DAC, the connection is susceptible to jitter. So the real answer to your question is it depends on how well the Wyred 4 Sound DAC1 rejects jitter through each of its inputs. Also, there very well may be sonic differences between the inputs—jitter aside. While this is more than likely the last thing you want to hear, the best way to know which connection sounds best is to listen.

I'd also recommend reading John Atkinson's review of the V-Link. Here's a relevant quote, "The electrical output of the V-Link doesn't appear to be connected with a pulse transformer, which means that it's possible that the grounds of some DACs will not be galvanically isolated from that of the host computer. This, presumably, is why Musical Fidelity's Antony Michaelson recommended to me that I use the V-Link's TosLink output if possible." This would suggest that your better S/PDIF option is TosLink but I'd still recommend giving Coax a listen.

I've heard very good things about the Wyred 4 Sound DAC1 and I'd be very interested in hearing which method you find works best. I also plan to get this DAC in for review at some point and when/if I do I will make it a point to try the various scenarios you've asked about (I have the Musical Fidelity V-Link here as well).

Thanks again for Asking AudioStream.


John C Freeman's picture

Hello Ask Audiostream,

I am presently using a Logitech Duet and accompany reciever to get my music to my Stereo System that is a room away from the computer. It seems to work realy good, but I have some questions about the operation of this hardware and software. Does the computer use the sound card to process the bit stream?  Would a external DAC help and how wuold I hook into the Logitech system.

Thank you.


firedog's picture

Lots of users report improved sonics using the V-link or other quality USB>SPDIF converter. (Including. by the way, Steven Stone of the Absolute Sound.) Apparently lots of setups are improved by the quality of the Vlink implementation relative to the USB implementation of the DAC,

YMMV of course

jllaudio's picture

I'm trying to find a US supplier of an enhanced power supply replacement for the Logitech Touch.

Mark916's picture

This is a great site by the way, just found it from your Scott Wilkerson video interview. I like this site allot as it covers allot of computer related gear, software and Audiophile side of the house.

I was at my local computer electronics store over the weekend checking out the latest sales, and found the Creative Sound Blaster X-Fi HD USB Headphone DAC which claims to have Audiophile components. Has Audiostream had a chance to review this unit, it seems fairly priced under $100. I know Creative is not really considered high end when it comes to audio gear, but they have been around for some time making sound cards for years. Is this unit something to consider if looking for decent DAC or Headphone DAC. My years and years of CD buying has been converted to FLAC format with DbPowerAmp software in the last 2 years, so I do listen to many tracks uncompressed nowadays. Could I benefit from this DAC from Creative?


Mark / Sacramento

Michael Lavorgna's picture

I have not reviewed (or heard) the Creative Sound Blaster X-Fi HD USB Headphone DAC. Can you shoot me an email and tell me as much as you can about the rest of your setup? Specifically what headphones do you have and what computer do you use.

nebojones's picture

I am looking for a simple (and, I hope, inexpensive) device.  I have ripped my 1200 CDs to FLAC files using dBpoweramp and saved them on a 2T USB 3.0 hard drive.  I have an NAD amp and a pair of PSB tower speakers.  What is the simplest way for me to play my music on my system?  It seems to me that networking my hard drive should not be necessary.  I can imagine a small box that has a USB input for the hard drive and a stereo pair of analog outputs for RCA cables that connect to the jacks on the back of the amp.  This box should have a remote control that would allow me to select the music I want to hear; when I pick a song, it should read it from the drive, convert it to analog, and send it along to the amp.  In analogy to record players, cassette players, and CD players (all of which play actually music, albeit from a specific medium), I think of this as a hard drive player.  It should be dead simple to use, with no installation required except to plug it in and connect the cables.  Does such a device exist?

Michael Lavorgna's picture

The Logitech Squeezebox Touch.

Cost = $299.99 (but I’ve seen it for less if you shop around. Amazon currently has it for $233.24)

Connect your hard drive via USB, plays FLAC files, has a touch screen, a remote, and a remote app for Android or iOS devices, and RCA output. It also has digital outputs (Coax and Toslink) if you ever want to add a higher grade DAC.

I should mention the SBT does all of this by installing its own music server software on your hard drive (but it does this automatically when you first connect it).

nebojones's picture

Thanks for the suggestion of the Logitech Squeezebox Touch.  I followed your link, but still have a couple of questions.

(1) Suppose I have a cabin by the lake (I don't, but let's assume that I do) and that I already have an amp and speakers there, but no computer, no wireless router, no cable modem, no cable service, no cell phone service, and no internet access.  I buy the Logitech Touch and take it to my cabin, along with my hard drive filled with wonderful music.  I am anticipating being able to sit on my couch and conveniently select and listen to my music without having to get up and walk all the way across the room (did I mention it's a big cabin?) to my hi-fi system .  Will the Touch enable me to do so?

(2)  Also assume that I have an iPhone (which I actually do have), and that I wish to use it as a remote for accessing my music.  Will that be possible at my cabin?

Michael Lavorgna's picture

(1) I believe you can use the SBT with just a USB-attached hard drive since the SBT has a built-in server. There are some limitations relating to the size of the library when using it this way but from what I’ve read you should be OK with around 1200 CDs.  And the included infrared remote will work just fine unless that cabin-in-your-mind is really big and you are really far away.

(2) Since you do not have a network or cell service in your hypothetical cabin, your iPhone can’t talk to anyone or anything except itself. So no, you cannot use it as a remote.

nebojones's picture

Thanks for the information; it looks as if this come pretty close to meeting my criteria for a hard-drive player.  You clearly know more about this device than Logitech's own web site provides.  Logitech seems to be emphasizing its networking capabilities and not to be publicizing the possibilities of using it in a no-network environment. 

Now all I have to do is to decide whether to spend my money on the Squeezebox Touch or to save up to buy the cabin....

Michael Lavorgna's picture

And you could always buy a nice used ukulele for a few bucks. You wouldn't even need electricity.

stephhance001's picture

Depending on the circumstance, they may work equally well. Both have the potential to be sonically transparent, that is have no audible effect on sound quality. Either can possibly be sonically perfect and ideal. -Steven C. Wyer

discojets's picture

I need help evaluating my computer audio set up.  This is how my system works.  I buy CDs and rip them as lossless files into my iMac.  The signal is then sent from my computer via CAT 6 to a router in a closet, then on to an Airport Express which sends it via CAT 6 to an Apple TV box connected optically to my Arcam AVR 350 receiver.  Here are my questions:  Can problems occur while ripping CD's into my iMac?  Can the digital signal suffer any degredation as it travels over the CAT 6 throughout the house?  Is the DAC in my Arcam (Wofson 24 bit 192 kHz) adequate?  Thanks for any insight you can provide.

Michael Lavorgna's picture

I believe that Apple TV only outputs 16/48 which is not really an issue unless you want to try HD music or are concerned about bit-perfect playback of 16/44.1. If you have any HD tracks, they will get downsampled before getting to your Arcam's DAC.

In terms of your Cat 6 network, this should not present any issues and ripping with iTunes is also fine. Make sure you have the "Use error correction..." checkbox checked under Preferences > Import Settings.

kiwi2000's picture


I am new to computer audio and I like ti. I have transferred all of my CD music to a desk top hard drive apparently utilizing windows media audio lossless to rip the music. It shows a bit rate of 470 to 940 kbps. This is then routed thro0ugh my pre amp processor a Marantz Av-8003 via a computer cable from the hard drtive. The cable looks like a big phone jack and it is red.


Question how do I know that wht is being ripped is lossless? It sure does not sound that way. If that is as good as computer audio gets it is not that good. A real disc blows it away in terms of sound quality in my home set up.

Question Is there a product I can incorporate that will provide for superior audio playback? Replacing the Marantz is not an option.

I woudlike to ty the HD downloads but cannot incorporate playback as it currently stands.

Thanks for your time.