Which of these digital interface schemes would be best ?

[percy]

For extracting digital audio from a PC and sending it to a DAC, what would be the best scheme to implement ?

1. An all out integrated USB DAC - like something based on PCM2702(example).
2. Convert USB to I²S and send to an I²S DAC.
3. Convert USB to spdif and send to a spdif DAC.
4. Use a PCI soundcard that has an I²S output (and has bit and rate accurate output i.e. does not resample), then send it to an I²S DAC.
5. same as above except S/PDIF instead of I²S
6. others ? please feel free to suggest any other that might be worth considering.

Any tested and tried firewire DAC solutions out there yet btw ?

[Hattori Hanzo]

I would generally prefer I2S connections over SPDIF (correct implementation assumed). You get 1. and 2. in one by using a PCM2707, see e.g. www.dddac.de. If you choose the SPDIF route I would just get one of those external USB audio interfaces that offer digital out via toslink or coax.

[ble0t]

You can check out this thread for some additional ideas...

http://www6.head-fi.org/forums/showthread.php?t=157955

[Ulas]

Originally posted by percy
For extracting digital audio from a PC and sending it to a DAC, what would be the best scheme to implement ?

None of the above. They all use PLLs and/or clocks that are remote from the DAC itself. If you really want the best PC/DAC interface you will have to make it yourself. All you need is a good DAC with a local clock. Software on the PC reads portions of the wave file, as needed, into a FIFO. The DAC reads samples from the FIFO at the rate determined by its own clock. The FIFO needs to be large enough to accommodate the expected latency of disk reads to keep the FIFO full.

[percy]

Ulas,
I have absolutely no idea what you are trying to suggest.
It will be a diy dac however.