Sound Card with External DAC

I see. Then I suspect that these transports doesn't maintain the purity of the signal, i.e. they manipulate the signal somehow.

I really want to see some strong argument that a bit is more than just a bit. In the analog world, we know how more expensive gears manipulate the signal to sound "expensive" with all the filters along the way. In the digital world, unless then data is manipulated, then it will remain exactly as what recorded on the CD.

I'm not questioning "high-quality" audio since my point is stressing that the digital data read by CDROM is as pure as what is on the CD. We all know that pure data doesn't necessarily sounds good, as well as expensive speakers never have real flat response. My point is audio signal purity, which comes from data integrity kept in a computer.

I sold my california audio labs transport/DAC pair, and am using my CDROM and my computer as the audio source. The signal is kept in digital from the CDROM till it gets out from the computer box, and converted to analog by the Stereo-link 20-bit DAC (CD audio is 16-bit).

I would never turn back.

data is data, audio or other data (word document, software, etc), they are all data.

If you say you can't rely on CDROMs to read audio data, then you also can't rely on the CDROM to read the Microsoft Office installation CD that you paid $700 for it. I don't know. Does not make any sense to me.

yes, CDROMs transfer data. If you don't do D-A conversion till the audio data gets out of the computer, then nothing is lost along the way. A bit is a bit. We are in digital world here. Until the digital data is converted to analog signal, then nothing is lost. Some error checking is performed when the CDRom is reading data, either by the operating system, or the IDE controller, or the CDROm itself.

Who uses CDROM's built-in DAC these days? Windows XP reads audio data in digital by default.

yes the computer transfers and works with data. Digital audio is one form of data. Data integrity is very important in computer design. It is an insult to a computer engineer to say that the computer does not maintain data integrity.

Once you got the data out of the computer, then it is pretty much up to the DAC to give you an interpretation of the digital data.

You're right. It is an insult to an audiophile to conclude that all his hard earned money and time are misguided on useless CD transports and high dollar digital cables.

My point is, CD-audio data is read correctly in digital by CDROM drives, and nothing is loss until it is manipulated or converted to analog. Whatever is stored on disk is read "as is" by the stupid CDROM drive. Hehe, you want pure signal path, the digital signal path is as pure as you can get. :) Data integrity is always the case in the computer. If it is not the case, imagine corrupted files and data happening all the time as you're working with a computer. Since corrupted files and data happen like once in a blue moon on a healthy computer, then you can be sure that data that contains audio information is kept in its full integrity as well.

Well, we're not talking about error-correction stuffs when reading the CD by the CDROM, but the same error-correction is used for other types of data (i.e. spreadsheet, documents) as well.

At the end of the pure digital path, you got a DAC. This is where the action is. Some DAC do tricks like upsampling and others do tricks like dithering. As long as the CD audio data is concerned, it remains pure until this stage.

Dejittering? for what? a bit, is a bit.