DAC inside CD Player with aux digital input

[ergo]

I have a setup at the moment where I have an upgaded non os DAC inside the cd player. It's fed by I2S signal from servo/decoder IC. Now I'm in the point where I would like to make a proper PCB for it. But, as I also watch movies etc. and would like to use the same DAC I'd like to include SPDIF input to this setup.

Have any of you guys done something similar? The main point being to keep the I2S connection inside player but to add switchable SPDIF input with help of for example CS8412. What would be the best method to switch these signal. If I could program programmable logic then I quess that would be the way to go, but as I can't, is there any other solution you can suggest to me?

Ergo

 

[sonnya]

You can do the shift/routing between the I2S in the dac and CS8412 with 4 nand and 8 or gates.. i think . And still be able keep no timing difference in a the 4 signals.

It can be a bit difficult with PLD if you are a "beginner" at this point .. But hey we all have to learn somehow!

Sonny

 

[KasperM]

Maybe do the switching with an ordinary multiplexer. A device like the 74F157 should be up to the task.

Offcourse there is no control on where, with respect to the timing of the serial audio transmission, the four signals are switched. I mean when you switch from one input to the other you will probably introduce a strange signal to the DAC. If you build the DAC circuit yourself you can just hold the DAC in reset state when you change the input.

Kasper M