Discrete DAC i2s

[hugobors]

Hello,

I red with a lot of interest the threads speaking of dicrete dac and want to build one.

I want a direct interface with i2s and r2r ladder.

My problem is how to do the serial to // conversion from i2s. So I made a measure on the i2s signal inside a Marantz CDPlayer, and it look like there is 24 BCK during low LRCK and 24 BCK during high LRCK.
So I made a schematic with 74HC164, and wanted to have your advices...

Do i2s signal always have 48 BCK during one LRCK period, so 48x Fs?? I've red on pcm2707 datasheet, that the i2s from it is 64xFs... If that's right, I have to put 2 more 164 to interface i2s with the r2r ladder...

Interrest on my design (if it works) is that Left and Right will arrive at the same instant...


Another question on i2s that is not clear (for me at least) is wich chanel comes first... For what I understand it's left. Am I right???

Thanks
Hugues