IDE CD-ROM to sound card signal - digital or analog ?

[percy]

Is the sound card DACs or the onboard DACs of the CD-ROM that do the work when you play a CD in a CD-ROM on a IDE channel ?
In other words does a digital signal go to sound card via the IDE/PCI bus or is it analog ? I am running WindowsME and Santa Cruz Turtle Beach sound card. I think the drive is a Lite-on CD writer.

If its analog, how can I make sure the drive is sending digital and the sound card is decoding it ? I would like to use the sound card dacs.

If its digital then is there any difference between the digital going through the IDE/PCI bus versus going through the 2-pin SPDIF connector that is both on the card and the drive ?

TIA.

[gmarsh]

Unplug the analog and SPDIF cables from the CDROM drive. If you still get sound, then the OS is reading audio samples directly from the drive via the IDE interface.

Most OSes (XP, OSX, etc) do this by default now.

[percy]

currently there are no other cables connected to the drive except for the IDE connector and ofcourse the power connector.

then the OS is reading audio samples directly from the drive

by "audio samples" you mean digital, right ?

[pburke]

Originally posted by percy
currently there are no other cables connected to the drive except for the IDE connector and ofcourse the power connector.



by "audio samples" you mean digital, right ?

well, yes - IDE cables don't have any wires reserved for audio transmission to the computer's motherboard.

Peter

[percy]

ah! ofcourse. didn't think that way.


There were no comments on the SPDIF v/s IDE connection question though.

What do people who have a serious PC audio setup do in this case ?

The SPDIF is just a short run (~6") straight to the card. IDE goes through the bus, memory, motherboard..
My mainboard is not the best - a cheapo PCChips.

[percy]

Ok sorry but now I am confused. Buried somewhere in the sound card manual it says about the CD Digital Input(2-pin) on the card -

"In WindowsXP, this connector is not needed, as the digital CD signal is sent directly through the PCI bus".

So if WindowsXP sends digital through the PCI bus, then what do the non-XP windows OS's do ? What do they send ? Analog ??


It goes further to say -
"Santa Cruz features a CD-ROM Digital input header for connecting to the digital audio output of the latest CD-ROM drives. Using this connector lets you make digital audio data transfers from the CD-ROM drive to the Santa Cruz card, which
reduces the small amounts of noise and distortion introduced by unneccessary digital to analog conversions ?"

what digital to analog conversions ???

[gmarsh]

Originally posted by percy
What do people who have a serious PC audio setup do in this case ?

The SPDIF is just a short run (~6") straight to the card. IDE goes through the bus, memory, motherboard..
My mainboard is not the best - a cheapo PCChips.

Well, the data doesn't lose its "mojo" when it's transferred through IDE... in either case your soundcard's DAC ends up playing the same data, bit for bit.

edit: and the 'old' way of hooking up CDROM drives was using a 4-pin analog link between the drive and the soundcard. That's what they're referring to.