As a manufacturer, I have to be careful what I say. But let me put this in a way that many of you can probably relate to.
If we put out a product that had as much jitter as the Wadia, do you think that it would get a good review?
Yeah, we all know the answer to that.
JA's assertion appears to me that jitter is the DAC's problem to deal with. Again, if our latest product had that much jitter........
BTW, out latest product has less jitter than the last CD transport that we built.
Getting back to the technical side of things:
There are 2 ways to take care of the jitter the transport creates. One uses a ASRC. Some of us designers feel that any ASRC is going to do something to the sound, and what it does isn't always for the better. The internal math functions of them is simply not enough to do the job the right way. IOW, without lots of internal truncation of data. You can not pass HDCD data through one, if that gives you any clue as to how much they operate on the sound.
The other way is with a secondary analog PLL. (An ASRC is essentially a PLL, done in the digital domain.) The harder the PLL has to work to correct the incoming data, the more likely it will be to affect the sound in an undesirable manner.
All PLLs have a range, both upper and lower, over which they are effective. To be really effective, they have to go very low. But this affects lock-up time. The worst jitter is the really nasty stuff that is close to the carrier frequency.
All of the jitter tests use test tones, of one sort or another. Things change a lot with music present. There is an extremely high correlation to jitter and the music. If you were to listen to the PLL pin on any SPDIF RX chip, you can make out what you are listening to.
So, in practice, while a "good" DAC can handle the incoming jitter and clean it up, it is not a perfect cure-all.
Make any sense to you guys?
Pat