Quality of Digital-out is always the same regardless of manufacturer?

[datura647]

I have searched around for a while, and I found some info but nothing that really answers my question. Some time ago I purchased a Creative transport on b-stock because it was very cheap and it looked cool(I don't have it with me at this moment, I will post info once I get back into town). Basically it's a small plastic box with USB connectivity to a computer. It has optical/coax output, as well as L/R RCA output (maybe it has RCA input too..).

The noise of my computer was bothering me with my open headphones, so I decided to move all my gear (see sig) to the living room, and stream my music from my noisy comp over the WLAN to my quiet laptop. Previously I was feeding my DAC coax from my Audigy Platinum. The Creative box is so I can get a digital signal from my laptop.

So I have optical going to my dac from this Creative box. I don't know how to describe it, but the music seems more "muffled" or "unclear". My first question is, is it possible for this Creative box to be degrading my sound quality? I ask because it seems to me if there were problems with the digital stream, I would hear serious artifacts/noise/distortion, but it only makes it sound slightly muffled, the opposite of "open".

And my other question, I am planning on building a HTPC and the only things I care about audio-wise are silent operation and a perfect digital output for my DAC. I was looking at ESI Juli@ because it is clearly high quality, but I will not be using analog outputs so I might be wasting money. What is the cheapest solution that has 100% perfect digital out (no resampling, bit perfect, etc)?

 

[satshanti]

As a suggestion to the laster poster, but also the OP, who has a sound card with Cmedia chipset:

I've been using the cheapest PCI sound card I could get my hands on via eBay with Cmedia chipset and coaxial SPDIF out to feed my stand-alone DAC. The deciding factor is a set of custom-made bitperfect drivers, developed by a guy named dogbert especially for sound cards with a Cmedia 8738/8768 chipset. I can only recommend these. They can be downloaded at his website, on which more information can be found, like a list of all sound cards with these chipsets.

Use Foobar and Kernel Streaming through these and you don't need more.

 

[Currawong]

I posted a blog entry on jitter which people might find helpful.

 

[datura647]

Wow satshanti that is exactly what I was looking for, thank you! This should seriously be a sticky or something

 

[dvw]

There are a lot of information that are factually accurate but may or may not be applicable in the audio application.

in the early days of digital audio, jitter was identified as a major contributor to the deficiency of digital audio. Over the years, designers have improved jitter performance quite a bit. Most DAC chips are now quite jitter tolerance. The question is how much jitter can a person hear.

BTW, Curra, the graph that you're showing is not jitter. It's the rise time of a digital signal. For visualization of jitter, an eye diagram might be better. I don't want to go into the technical detail.

But, jitter do exist and they do make a difference. Is the difference acceptable, that's up to the individual.

The significantly worse case of jitter is in the telephone network. If you can't tell the difference between jitter in each individual call, most likely the jitter in the digital audio is not going to bother you.

 

[bass_nut]

i was looking for answer(s) to this one: kimber usb cable better than ordinary ones with regards music SQ output from laptop >> usb cable>> dac>> amp>> headphones?

thanks

 

[gregorio]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif It's probably a happy accident that you can stream dolby digital over these interfaces.

You've probably got it the wrong way around, which is not surprising as you are obviously music oriented. Digital audio for music has to a large extent been defined by the red-book standard for audio CDs which is 16bit, 44.1kFS/s. It is only because of this CD standard that you have this 44.1k sample rate fixed in your mind. All other areas of digital audio, TV and Film for example, have always been 48kHz. So it's not a coincidence that DD, DTS, etc., work with these interfaces.

G

 

[dvw]

Quote:

Originally Posted by bass_nut /img/forum/go_quote.gif i was looking for answer(s) to this one: kimber usb cable better than ordinary ones with regards music SQ output from laptop >> usb cable>> dac>> amp>> headphones? thanks

No. USB is a complete different animal. USB protocol uses packets to transmit data so jitter is not in the transmission path.

There will be people that give different answer. But if you looking for a logical and scientific answer. The answer is USB cable does not make a difference.

 

[datura647]

I'm back home and I realize this Creative "box" is actually a sound card. It is model SB0270. So does anybody think that doing USB to optical using this box can degrade my sound quality? Again, what I believe I am noticing is a slight drop in overall clarity of the music and not any obvious noise/artifacts.

 

[gregorio]

Quote:

Originally Posted by datura647 /img/forum/go_quote.gif I'm back home and I realize this Creative "box" is actually a sound card. It is model SB0270. So does anybody think that doing USB to optical using this box can degrade my sound quality? Again, what I believe I am noticing is a slight drop in overall clarity of the music and not any obvious noise/artifacts.

In principle the Creative box shouldn't make a difference. In practice though it's difficult to know exactly what processing the box is actually doing and therefore, it's possible that what you are hearing is a real phenomenon rather than imagined.

G