WOW! By making this 2 posts, I am now a Senior Member. Is anyone impressed? I hope not.
Anyway, Part Due.... "Now that you have our interest, you aren't going to crap out now, are you?" No. This is the point for someone who is skeptical to go: "Hey, aren't you the bozo who told us to get a decent CD player, and ............... Yes. "But here you are telling us how bad they are, and how the Duet is better, and since none of us even have CD players any longer............." Yes, true. But....... A CD player only has one sampling frequency. One sampling frequency, one frequency source. (IOW, only one clock.) "Uh.........I think I know where you are headed." Right. Back to get my lithium level adjusted again. Uh, where was I? Oh, yeah; one clock as opposed to two clocks. I would suggest for those of you who are interested in jitter to use a single clock device (that has a SPDIF output) as opposed to a multiple clock device. That is why I said CD player, as opposed to one of the fine products that the owners of this forum produce. So, that gets us (finally!) to what you are really interested in: the jitter in your outboard DAC. Admittedly, there are some brands that deal with the issue better than others. I do not know one brand from the next, so I would honestly have no way of knowing. "But can you give us some hints on what to look for?" Well, any DAC that uses a ASRC, even as much as I don't like them, will address the jitter issue and reduce it. How much? Without having one in my hands to measure, no way of saying. Look, at one time, the SPDIF receiver chips generated as much as 1 nSec of jitter. Horrible. Some brands claim that they got down to 200 pSec or so. I don't believe them, but in all honesty they should be able to perform better than the ones that only did 1 nSec. (Should, because there are ways to muck them up.) We presently have brands that claim to be under 100 pSec. I have some of those in the queue to measure, but have not yet done so. But let us assume that they will do 100 pSec, and that nothing happens internally to muck it up. (Wishful thinking, perhaps.) So............let's say the typical outboard DAC -without any fancy jitter reducing circuitry- will be no better than 100 pSec. Compare that to say........5 pSec for a really good CD player. Or should I say what a really good CD player -should- be. (More wishful thinking.) So, is that important? I dunno. You are the ones listening to it. Not me. You have to decide for yourselves. Unfortunately, there is really no way for the consumer to know how much jitter a unit has. Sure, you see some gibberish in a magazine, but that really says nothing except how special the magazine thinks that they are. Read the marketing goop that comes with the unit? Probably about as useless. So, here is the best advice that I can offer: If you have a typical CD player, it probably does not have enough jitter to worry about. Yes, could be better, but better comes with a price tag. Price tag does not promise performance, though. If you have Duet, or SB3, it is probably low enough. *Especially when you consider what they cost*. A lot of stuff for not a whole lot of money. Sure, there are ways they could be better. I assume that is the genesis of the Transporter. If you have an outboard DAC thingie: Listen to the source's analogue output (assuming it has one). Listen to your DAC thingie. -If the output, in comparison, has loose and flabby bass, and/or rough and harsh top end, then you may have jitter issues-. If it sounds good enough, then it doesn't matter. Even if it could be better. Better means more money. And more money does not mean better. Only more money. Any more questions? I am typed out, and still have e-mail to answer. Pat -- ar-t http://www.analogresearch-technology.net ------------------------------------------------------------------------ ar-t's Profile: http://forums.slimdevices.com/member.php?userid=13619 View this thread: http://forums.slimdevices.com/showthread.php?t=56425 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
