I2S - a newbie is confused.

[adhoc]

I read this over in another forum:

Data comes off the CD transport itself as I2S data, which seperates the bit clock and word clock out from the PCM audio data. This format is, for all intents and purposes, immune to jitter. It then hits a digital converter, which then spits out S/PDIF. On the other end, a DAC that has a S/PDIF input driver, or a S/PDIF to I2S converter, then the DAC. Now why exactly more high end transport/DAC manufactuers aren't using external I2S is beyond me. Audio Alchemy used it a lot, so did Sonic Frontiers. I think Camelot still does, but I'm not sure as their web site is garbage. You'd think on a $2000 CD transport they could put $1 worth of parts in for an I2S jack.

Now I'm really confused. What's with all the jitter readings for USB-to-I2S convertors then? What would be a good transport for getting I2S data out then?

[jeff mai]

Originally posted by adhoc

This format is, for all intents and purposes, immune to jitter.

That statement isn't true. Does that make things a little clearer?

[adhoc]

Originally posted by jeff mai


That statement isn't true. Does that make things a little clearer?

care to elaborate why? if i buffer this i2s signal and then clock it, would that eliminate jitter (disregard drifting)?

[Guido Tent]

Originally posted by adhoc
I read this over in another forum:

Data comes off the CD transport itself as I2S data, which seperates the bit clock and word clock out from the PCM audio data. This format is, for all intents and purposes, immune to jitter. It then hits a digital converter, which then spits out S/PDIF. On the other end, a DAC that has a S/PDIF input driver, or a S/PDIF to I2S converter, then the DAC. Now why exactly more high end transport/DAC manufactuers aren't using external I2S is beyond me. Audio Alchemy used it a lot, so did Sonic Frontiers. I think Camelot still does, but I'm not sure as their web site is garbage. You'd think on a $2000 CD transport they could put $1 worth of parts in for an I2S jack.

Now I'm really confused. What's with all the jitter readings for USB-to-I2S convertors then? What would be a good transport for getting I2S data out then?

Hi

The I2S interface conceptually is well laid out for low jitter data transport. However everything depends on implementation hence low jitter master clocks should be sitting at the DA, and reclock all incoming (jittery) data

With USB, the clock at the DAC cannot always be the slave, so there you go......

Philips CDpro2 is a good drive with I2S out

best

[adhoc]

Guido,

Thank you for that reply. I still have much to learn - which, surprisingly, I am pretty excited about!

Cheers!