A couple of questions about I2S

[captain]

A couple of question about I2S. My DAC is set up to input via I2S and I am considering using this as the input to the DAC.
I realise you need to open up what ever CDP you are going to use as a transport and connect it up internally. Just need to know will all CDP connect up this way when used as the transport, also I am presuming connecting this way will bypass the clock in the DAC and use the one form the CDP. Finally is connecting to a DAC via I2S better then using SPDIF or Optical if so why.

[leo]

Not all cdp's use I2S, it really depends on the type of chip set used, you need to know the circuitry

Obviously theres much more to it but to keep it quick I2S tends to be better as long as its not run above its limits , main limit being the distance, I2S needs to be kept as short as possible where as spdif is better suited over longer distances

One of the reasons I2S is better is because your running direct rather than having to convert I2S to spdif back to I2S

[captain]

Thanks Leo

[Themis]

Another advantage of I2S over SPDIF is transmitting separately the clock and the data.

[harrylime6]

A couple of question about I2S. My DAC is set up to input via I2S and I am considering using this as the input to the DAC.
I realise you need to open up what ever CDP you are going to use as a transport and connect it up internally. Just need to know will all CDP connect up this way when used as the transport, also I am presuming connecting this way will bypass the clock in the DAC and use the one form the CDP. Finally is connecting to a DAC via I2S better then using SPDIF or Optical if so why.
On my set up the I2S signal is taken directly from a Philips CD-PRO2 module via a JST PH series six pin connector. Having a CD module with an I2S "out" makes life much simpler. Leo has explained the nut of I2S above, so all I can add is that, in my set up, I prefer the I2S sound to the sound of SPDIF or Toslink. I have any number of friends who feel it their mission to convince me that there cannot possibly be a difference in sound between I2S, Toslink, SPDIF or any other means of digital transfer ... but, to my ears, there is a difference. Will the difference be to your liking? Don't know. The crucial part for your project, I would think, would be to determine (in your CDP) the tapping point from which you can steal the I2S signal ... if there is one. Sourcing a service manual for your CDP would be my next step if I were myself in your position. Hope this has helped.
-harry

[Primalsea]

Im fairly (dont quote me) certain that most of the old Marantz players with TDA dacs use I2S. Also fairly certain the Cambridge Audio D300SE has it also. You can pick these up quite cheap on ebay these days. I have the service mnauals for a CD94 & the D300SE somewhere if you need them.

If you know for sure a CDP uses I2S and you dont have the service manual you can check the datasheet for the DAC and see what pins the signals go to and then follow them with a fine line pen on the PCB back to the origin. You would have to check the datasheets of any other IC's that the signal goes through to establish there purpose, such as data reclocking etc. Be warned following PCB tracks is a maddening experience!

I dont know for sure but at a guess I would say that you could make a buffer with 3 high speed single opamps so that the I2S cabling could be longer if required.

[captain]

Thanks for the info