Wondering...direct digital out on a computer?

[noddin0ff]

I've been wondering about this for a while, and the Sndrox thread got me wondering again...

So, I have a cheap USB DAC on my laptop. But I know it doesn’t get a raw PCM from the computer because I can EQ the signal and adjust the volume with iTunes even if I’m using iTunes to play a CD rather than a file. That implies to me that the software is messing with the signal prior to digital output. Even if I turn EQ off in iTunes, the volume controls will still attenuate the volume throught the USB output. It IS as digital signal exiting the USB port, right? If I was after sonic perfection I’d want the signal passed directly to the DAC. I know a CD player with a digital out would do this.

Since you need software analogous to iTunes to listen to files on your computer. Is it possible to get an unadulterated digital output?

[Slosh]

If you have the eq/effects turned off and the iTunes volume all the way up and have the sound device manager set up for digital output only and at 44kHz/16-bit it should be no different than using a CD transport.

I set up my device manager to output 48kHz/24-bit so I can play PCM concert DVDs without down rez-ing (in most cases). I can bump that up to 96kHz if I want but then the receiver I'm using with the PC locks into stereo direct mode and I like to employ the sub. I don't hear any difference with CDs, wavs, or lossless files with it at 48/24 but it doesn't seem to slow the PC down any so why lower it to CD spec?

[noddin0ff]

Thanks, Slosh...it's that "should" part. (not that I'd notice sonic perfection if it happened).

...sound device manager...

This could be one of those areas where Mac OS X gives less flexibility. With my stock powerbook. I can chose USB output through the system prefs, but there's no further management (44kHz/16 etc.) beyond volume at the system level. Maybe this is something OS10.4 lets you do...I'm still 10.3.