DAC input selection

[pixpop]

I've built my version of a DDDAC, and am adding a TOSLINK connector. But I don't want to add a switch to select coax or optical.

Can I simply feed both inputs into the CS8414 via separate capacitors? Obviously, I would only have one source connected at a time.

Alternatively, does anyone have a suggestion for a minimal parts count auto selector that would, for example, select the optical if there was a signal on the optical, otherwise select the coax?

The signal from the optical receiver is digital, CMOS levels, but I'm not sure about the signal on the coax.. can I receive it with a standard digital component, such as 74HC14?

thanks,

Neil

[EC8010]

S/PDIF is only 500mV into a 75 Ohm load. To receive it properly, you need a proper receiver chip. Alternatively, you need a video op-amp to amplify it, then AC couple and DC restore it (to make the signal swing 0V to +5V, rather than -2.5V to +2.5V). Once you've got logic level, it should be easy enough to add some circuitry to detect which input is active and to select it.