Why does source matter when I'm only using a Digital Output?

[lipidicman]

This is a really informative thread for those of us contemplating moving from CD to using a computer and DAC. Will anything ever approach even my lowly CD63KI. Somehow I doubt it. So maybe I upgrade to another dedicated CD player.

It is very helpful to understand the drawbacks of SPDIF and the clocking signal. Is usb DAC any better eg in the headroom desktop amps?

 

[hciman77]

Quote:

Originally Posted by lipidicman This is a really informative thread for those of us contemplating moving from CD to using a computer and DAC. Will anything ever approach even my lowly CD63KI. Somehow I doubt it. So maybe I upgrade to another dedicated CD player.

Now here is the kicker. Marantz CD players are notoriously bad in terms of measured jitter - they not iinfrequently top 500 - 670ps yet they still sound fine. In one test a guy on TNT accidentally added 500ps jitter to a playback - he never really explained how - and he did not find the sound notably worse - actually he preferred it - I pass no judgment on this finding.

 

[alex_cs]

Quote:

Originally Posted by regal This couldn't be further from the truth. Jitter has little to do with reading the CD. It is mostly introduced in the clocking and clock transmission to the DAC. Computers soundcards have measured much worse than even mediocre CDP's. This is because of the rippled SM power feeding the soundcard's clock. When have you ever seen a decent powersupply feeding a soundcard or even just its clock? Until then a computer even when used as a transport to a DAC will have more jitter than a CDP. The question at hand : is that jitter difference audible?

where is this proof? what cards where used, what power supplies?

 

[freeflier]

Quote:

Originally Posted by Scrith Actually, in the case of a CD player, I think the thing to consider is how good it is at accurately retrieving the digital information off of the CD in real time. As anyone who has tried to accurately rip a damaged (visible or not visible) CD can tell you, the process is often time consuming because the CD/DVD player cannot read it well without many, many passes. It's quite possible that a higher-priced player would contain a larger RAM buffer and a faster reading mechanism so that it could read further ahead in order to devote more time to difficult-to-read parts of the CD. The reality is that many CDs cannot be read without errors in real time. This is the main reason why using a CD player, no matter what the cost, is inherently inferior to using a computer as your source.

What he said!

Personaly I wouldn't have beleived it if I hadn't inadvertantly stumbled on this blatantly audible difference myself when I went to a PC/Squeezebox as a digital source feeding the processors in my main high end rig. (and I've had some very good digital gear in the past and heard most of the best there is)