Optical Audio - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 9 Old 09-28-2009, 10:48 AM - Thread Starter
Senior Member
 
redtyler1's Avatar
 
Join Date: Jan 2007
Posts: 423
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I have a simple question. I am creating a 2 channel listening area and will be playing FLAC files from my HTPC. The HTPC will be connected to an external Digital Audio Converter (DAC) then to an all tube amplifier. My question is how should I connect the HTPC to the DAC? There are three options 1. optical, 2. coaxial, and 3. USB.

I have been leaning towards optical, because of the lack of noise, but I am happy to hear other thoughts.

Given that I am leaning towards optical, can i use the on-board optical or do I need to invest in a sound card with optical out? Will there be a difference in the sound quality?

Thanks for any help!

Alex
redtyler1 is offline  
Sponsored Links
Advertisement
 
post #2 of 9 Old 09-28-2009, 12:02 PM
Member
 
posies2323's Avatar
 
Join Date: Nov 2005
Location: Seattle, WA
Posts: 85
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The chip supporting the USB connection often will not support 24-bit files and can be subject to jitter. Between coaxial and optical, I would use the optical. Optical usually sounds cleaner to me than coaxial. I would have said a few years ago to obtain an external sound card. But recent computers are using better chips for their internal soundcards as the chip's computing power increases and their unit cost decreases.
posies2323 is offline  
post #3 of 9 Old 09-28-2009, 12:30 PM - Thread Starter
Senior Member
 
redtyler1's Avatar
 
Join Date: Jan 2007
Posts: 423
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks very much!
redtyler1 is offline  
post #4 of 9 Old 09-28-2009, 12:34 PM
Member
 
abelincoln's Avatar
 
Join Date: Feb 2007
Posts: 149
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Posies, can you elaborate on the usb interface being subject to jitter? Isn't it the common perception that usb has less jitter since it sends music through buffering and asynchronous transfers?

Also, at least one popular usb dac, the Benchmark DAC1 USB, accepts signals up to 192/24. Is it really that unusual to find one that can play 24 bit material nowadays?

I have no experience with usb dacs myself but was just wondering since what you're saying seems to conflict with other things I've read.
abelincoln is offline  
post #5 of 9 Old 09-28-2009, 02:48 PM
Senior Member
 
ENiGmA1987's Avatar
 
Join Date: Feb 2009
Posts: 288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
If I had to guess, I would say that most modern external DACs use USB connection since that doesnt rely on a sound card or onboard sound to give it a coax or optical connection. ALL computers have USB, not all has an optical or coax output. That is the main reason I would see as to why external DACs use USB. Not because of better sound or anything. It really shouldnt matter at all what connection you use.
ENiGmA1987 is offline  
post #6 of 9 Old 09-28-2009, 03:34 PM
 
duvetyne's Avatar
 
Join Date: Dec 2008
Posts: 1,635
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:


I would say that most modern external DACs use USB connection since that doesnt rely on a sound card or onboard sound to give it a coax or optical connection.

A "USB DAC" is a "soundcard".
duvetyne is offline  
post #7 of 9 Old 09-28-2009, 04:20 PM
Senior Member
 
ENiGmA1987's Avatar
 
Join Date: Feb 2009
Posts: 288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by duvetyne View Post

A "USB DAC" is a "soundcard".

I know it does the same thing, but what I meant was that if it had analog inputs it would be pointless because it would be limited by the quality of the sound output on the computer. If it has an optical input, it is limited in the fact that not all computers have an optical output built in to the motherboard and it still runs through the processing chip on the motherboard, which sometimes would limit the bit depth and sampling frequency. Same thing for coax.

So the purpose of the USB input is not from a sound perspective but from an ease of use point of view.
ENiGmA1987 is offline  
post #8 of 9 Old 09-28-2009, 04:34 PM
 
duvetyne's Avatar
 
Join Date: Dec 2008
Posts: 1,635
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:


So the purpose of the USB input is not from a sound perspective but from an ease of use point of view.

You could replace the "USB input" with a PCI bus and it would still be a "sound card".
The only motherboards with optical or coax outputs are motherboards with onboard sound cards, which, in turn have optical or coax outputs.
duvetyne is offline  
post #9 of 9 Old 09-29-2009, 09:59 AM
Member
 
ktaillon's Avatar
 
Join Date: Jan 2006
Posts: 82
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
It sounds like your DAC has all 3 inputs, coax, optical and USB. If it's a built in sound card, either the coax or optical should be clean. If you need a long run to the DAC I would use the optical.

USB devices(sound cards) are getting better all the time. But if your computer can output a digital signal, why buy another sound card.

I too use a HTPC for my music source. I use the Roku which outputs a digital signal(coax) to my Pre/Pro. The DAC in the Roku was pretty bad.
ktaillon is offline  
Reply 2 Channel Audio

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off