For those that don't know, SPDIF splits the data and clock signals, introducing jitter and whatnot. The music has to go through this twice, I2S to SPDIF -cable- and then SPDIF to I2S. An imod does the same thing, straight to DAC with no SPDIF. All other external DAC that I know of use SPDIF.
Fair enough, I'm no genius. That's just how I remember Vinnie explaining it to me. I'll go find his email.
What's the correct info?
well firstly jitter is introduced into SPDIF, because of its fundamental design and the interface it uses (TOSLINK and Coaxial) jitter is actually greatly minimised by having a separate word clock and some DACs have this extra input to accept a clock from a master clock.
When an external DAC is used, if in conjunction with a CD player transport, then it may use I2S (depending on the chipset) which is then converted back to SPDIF and over the cable and into the receiver, but again, depending on the chipset at the receiving end may be converted back to I2S but afaik most don't.
As for the iMod, i think what vinnie is trying to say is that it doesn't use SPDIF at all, rather than the iMod bypassing it. He was comparing it to a 2 box solution, the same benefits could be applied to a single box CD player.
I think I've got it all right... =D
edit: also didn't mean to come across as an @$$ earlier, was in a hurry to make the post is all