USB Vs. Optical Vs. Coaxial

[SVghost]

I just purchased a Headroom Desktop Balanced Amp and a pair of recabled 'fatpipe' balanced DT880 cans. Im going to be using my computer as a source, i currently have a total bithead (so this is going to be an enormous upgrade as is)

Im wondering, and i think i may allready know the answer, what will give me the best sound quality possible. USB, Optical, or Coax?

I think optical because its not an electronic connection, its light, and that means 0 interference and 100% pure signal. I have a wifi router sitting on my desk, and if i put my total bithead in the wrong position i can hear the router (tho i think its actually interfering with the dac inside the amp, because when i rotate it it comes and goes) I think when my new toys come, ill be relocating the wifi router, so lets just keep the discussion to the thread title.

Thanks guys! Hey i think this is my first post btw! Hi im Dexter, a 21 year old, now poor, college student obsessed with sound quality and music. All my friends think im insane, with the exception of one.

 

[hypoicon]

Though it seems counter intuitive, in my experience the SPDIF coax has a bit of an edge.

 

[Kurotetsu]

Optical isn't necessarily the best due to lack of error correction and, depending on the cable, can be quite lossy.

USB has the edge due to error correction, however due to bandwidth limitation it can only support a 24-bit/96KHz signal (which, quite frankly, is PLENTY unless you have a receiver or something that can support anything higher). USB also bypasses whatever sound card you might be using, so you won't get any sound card specific capabilities like EAX if you use it. At the same time, bypassing the sound card can improve the sound dramatically depending how much the sound card messes with the signal.

Coax takes second place due to having more durable and easier to come by cables. You can also run it for a much longer distances than optical, and you can curve it around obstacles without degrading anything.

Optical's biggest advantage, compared to coax, is that it has an 'always on' signal. Some DACs or receivers open or close their digital connection depending whether a signal is being received or not (this is usually heard as a 'click' or something when you computer turns on, for example). With coax, you could possibly be hearing clicking more often as the connection opens and closes due to the presence or absence of a signal. Since optical is always on, this isn't an issue.

For music, I'd go with USB if error correction is supported, then coax if not.

 

[krmathis]

I put my vote for USB, since it allow direct conversion to I2S (no intermediate S/PDIF conversion).
Probably no major audible difference though, as all are great interfaces.

 

[Andrew_WOT]

Quote:

Originally Posted by krmathis /img/forum/go_quote.gif I put my vote for USB, since it allow direct conversion to I2S (no intermediate S/PDIF conversion). Probably no major audible difference though, as all are great interfaces.

How many USB DACs actually do that? Pico for once, anything else?

 

[krmathis]

Quote:

Originally Posted by Andrew_WOT /img/forum/go_quote.gif How many USB DACs actually do that? Pico for once, anything else?

No idea how many there are.
But I know the RWA Isabella and Isabellina does...

 

[SVghost]

Thanks for all the informative responses guys! And so quickly too!

I didn't think of that, but i think i agree with you. I'm a fan of a path of least resistance, and if the soundcard and DAC in the amp both have to work, the sound will be degraded.

USB it is! Ill be relocating my router then.

 

[HeadLover]

I don't know, I belive that if a COAX is good, it can better than a USB that isn't well implemented.

A lot of DAC's have USB now days, but not all of them has good ones.

 

[sonci]

Quote:

Originally Posted by SVghost /img/forum/go_quote.gif Thanks for all the informative responses guys! And so quickly too! I didn't think of that, but i think i agree with you. I'm a fan of a path of least resistance, and if the soundcard and DAC in the amp both have to work, the sound will be degraded. USB it is! Ill be relocating my router then.

Not if you have a RME or Lynx as the soundcard.
I have an EMU 1212M and I planning to use its digital out to an external DAC, not sure if I should bypass or not...

 

[Bredin]

If you are using windows, will a USB dac support ASIO or will it be better with a soundcard that supports ASIO and using a COAX cable to the dac.

 

[gabrielo]

Quote:

Originally Posted by Kurotetsu /img/forum/go_quote.gif Optical isn't necessarily the best due to lack of error correction and, depending on the cable, can be quite lossy.

I don't think errors are expected on optical link unless you broke the cable Quote:

USB has the edge due to error correction,

IIRC there are are error corrections defined for USB-Audio
Reason is that errors are very rare and it is much easier to simply drop the packet than retransmit (after all this is not critical data)

Quote:

Coax takes second place due to having more durable and easier to come by cables. You can also run it for a much longer distances than optical, and you can curve it around obstacles without degrading anything.

I think you are wrong here and optical should be able to carry the signal for longer distance without loss.
Still both will do fine for any reasonable setup.

 

[Phelonious Ponk]

If all are properly implemented, which is neither difficult nor rare, I doubt anyone would hear a difference (I doubt there would actually be any difference) in an blind listening test unless there was RF leaking into the non-optical lines. Even then, the interference would have to be pretty loud.

P

 

[faberryman]

There is an interesting article in The Absolute Sound this month about USB DACs. The USB interface does not recieve a very favorable rating compared to coax. The are a lot more choices among DACs if you go the coax or optical route. There are only a few USB DACs currently available.

 

[tosehee]

USB, in theory, should be superior, but how many usb implementations that actually have a good review?

Like HeadLover says, there is not that many usb DAC that provides really good implementations. When there is one, I'll sure look into that. But then, like Krmathis said, there might be no audible difference at all. So, don't sweat one over the other.

 

[Justin Uthadude]

Quote:

Originally Posted by Bredin /img/forum/go_quote.gif If you are using windows, will a USB dac support ASIO or will it be better with a soundcard that supports ASIO and using a COAX cable to the dac.

USB dacs supports asio and wasapi.

This is an excellent read. Look at the bottom for all the other hifi gurus' responses.