Basic Question on Jitter on PC audio
Jul 15, 2007 at 4:05 AM Post #16 of 401
Quote:

Originally Posted by Gatticus /img/forum/go_quote.gif
The fact is that PC as source has less jitter than CDP. Some people were saying otherwise. They are simply wrong. End of discussion.


First, calm down. lol!

The article seems to be comparing apples to oranges. And the conclusion that PC's have less jitter is subjective, not absolute. The scenario in this article is a PC using HDD(or other non-optical data storage) based audio, producing less jitter than an optical disc based system, whether it's the PC's ROM drive or an external CDP. But what of a PC playing CD-A compared to a CDP playing CD-A? What of a PC playing storage based audio vs. an external standalone unit which utilizes the same or similar storage based audio?

How do you define what the source is? If you're using an external DAC, then the PC is really only an extension of the source, where the data is kept; the PC is just the storage unit. But the external DAC is where the conversion and line driving takes place, as in the CDP so it only seems fair to consider the external DAC as the source, and not the PC. So the "fact" of the article appears to be that a PC produces less jitter using non-optical storage based media than a PC or standalone unit does using a drive to play CD's.

But IMO to be fair you would have to use the PC's internal hardware for it to be considered the source, otherwise it is again only a form of storage media and not truly the source.
 
Jul 15, 2007 at 8:33 AM Post #17 of 401
Quote:

Originally Posted by audioengr /img/forum/go_quote.gif
There can be a LOT of jitter in the USB signal from a computer.



And BTW, when I say "well-implemented", I'm talking about the USB interface, not the PC.



Ah, but you see, I don't use my EMU 0404 USB via the USB connection. I implement it correctly to get the least amount of jitter, less than any optical CDP. I use a digital coax connection from my X-Fi to my EMU. That connection has the least amount of jitter and not USB.

@Logistics. Sorry for getting uppity. Too much coffee.
smily_headphones1.gif
The article is talking about using digital files off the HDD compared to optical CDP and not a PC's optical CDP. That is how I play my music and rarely use PC optical CDP. In that scenario the PC is superior compared to a stand alone optical CDP. But as has been pointed out by Bigshot, it is probably an inaudible difference so is moot but it is a measurable difference.
 
Jul 15, 2007 at 6:12 PM Post #18 of 401
Quote:

Originally Posted by Gatticus /img/forum/go_quote.gif
Ah, but you see, I don't use my EMU 0404 USB via the USB connection. I implement it correctly to get the least amount of jitter, less than any optical CDP. I use a digital coax connection from my X-Fi to my EMU. That connection has the least amount of jitter and not USB.

@Logistics. Sorry for getting uppity. Too much coffee.
smily_headphones1.gif
The article is talking about using digital files off the HDD compared to optical CDP and not a PC's optical CDP. That is how I play my music and rarely use PC optical CDP. In that scenario the PC is superior compared to a stand alone optical CDP. But as has been pointed out by Bigshot, it is probably an inaudible difference so is moot but it is a measurable difference.


Digital S/PDIF is certainly better than Toslink, but a far cry from eliminating S/PDFI altogether. A 1.5m cable is recommended.

What I just discovered is that the 0404 can be slave-clocked from my Pace-Car reclocker. This will make jitter inaudible. The problem is that my current generation reclocker only outputs I2S, so you must have an I2S input DAC. Version 3 coming out later this summer will have S/PDIF output, but will have slightly higher jitter due to the S/PDIF interface.

Steve N.
Empirical Audio
 
Jul 15, 2007 at 9:18 PM Post #20 of 401
Quote:

Originally Posted by Redo /img/forum/go_quote.gif
That's all dependent on the external sound card. I doubt most external sound cards can match the nicer dedicated CDPs for jitter, though I don't really have any proof one way or the other.


something is wrong with your dog mate...
 
Jul 15, 2007 at 9:50 PM Post #21 of 401
Quote:

Originally Posted by maarek99 /img/forum/go_quote.gif
There is no difference in sound between usb or coax. You guys are unbelievable.


Maybe not but I've seen plenty of people post about issues using USB for sound. Probably because their mb has crap USB implementation.
 
Jul 15, 2007 at 10:23 PM Post #22 of 401
Quote:

3) reclocker - best


The Stello does a reclock. So it's jitter is dependant on it's internal clock, and the signalpath. If you prevent against buffer underruns, you're about set.
 
Jul 16, 2007 at 12:01 AM Post #23 of 401
Quote:

Originally Posted by Gatticus /img/forum/go_quote.gif
Maybe not but I've seen plenty of people post about issues using USB for sound. Probably because their mb has crap USB implementation.


I remember those posts, too! But IIRC, the concern was about the power rail coming off the USB; that it was dirty. However, wouldn't this mean that the +5V rail in the PSU is dirty and really has nothing to do with the USB?


Edit: I can't stop drinking teh coffeez, either. I've had periods where I stopped drinking it and I felt better overall, whereas I would otherwise be worked up and irritable, but... MUST HAVE TEH COFFEEZ!
 
Jul 16, 2007 at 3:11 AM Post #24 of 401
Quote:

Originally Posted by LeonvB /img/forum/go_quote.gif
The Stello does a reclock. So it's jitter is dependant on it's internal clock, and the signalpath. If you prevent against buffer underruns, you're about set.


If you believe that, I have some land in Florida I would like to sell you.....
 
Jul 16, 2007 at 3:12 AM Post #25 of 401
Quote:

Originally Posted by maarek99 /img/forum/go_quote.gif
There is no difference in sound between usb or coax. You guys are unbelievable.


No, you are inexperienced.
 
Jul 16, 2007 at 4:00 PM Post #27 of 401
I read an article about some guy who was a symphony musician and he claimed his $10,000 speaker cables made a huge difference to the sound quality of his stereo. He was definately placebo'd. Poor sucker.
 
Jul 17, 2007 at 5:43 PM Post #29 of 401
Quote:

Originally Posted by korben_dallas /img/forum/go_quote.gif
Steve,

Have you experimented with HDMI as a transport?


No. I2S will be better anyway. It is the native interface for the D/A chip.

Steve N.
 
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