USB DAC with conventional transport ???


Does anyone make a conventional CD transport that outputs an asynchronous digital signal via USB? Wouldn't it be nice to be able to use one of these excellent (and relatively inexpensive) USB DACs without a computer as the transport? If nobody makes such a CD transport, is there any reason that one could not be made if someone wanted to do so?
poetcatullus
Could you use an spdif-usb converter? I have heard good things about them, though acknowledge each time you insert a new component in between 2 existing components, there is a risk of degradation. Nevertheless, it is just a thought, in terms of getting you to where i think you want to be. perhaps you have already investigated? If so, curious as to your findings. thanks.
Lloyd, you may be thinking of USB to S/PDIF converters, or perhaps devices that can convert a S/PDIF signal such that it can be provided TO the USB port of a computer. I'm not sure that a S/PDIF to USB converter, that can EMULATE the USB port of a computer, exists.

Supplying a USB signal to a USB DAC requires that the signal source act as a "host," rather than as a "slave," which means that either it has to be a computer, including CPU, driver software, etc., or it has to emulate one.

I don't know of any transports or converters that are designed to do that, although perhaps some exist that I am not aware of.

Best regards,
-- Al
Thanks, Al...guess you can tell i am only a redbook cd guy with a transport! ;) Only fleeting interest in servers for now. will make sure to post here before i ever do investigate servers properly!
Thank you, Al; for that excellent description!

I doubt that anyone currently makes a conventional CD transport that emulates the USB port of a computer - and "emulates" is the key word here. But one would think that such a transport is theoretically possible and could be relatively inexpensive. The CD drive would have to be smooth and quiet, unlike many found in computers. I have heard tell that Sanyo makes such an OEM CD drive (for conventional players) and I imagine that Matsushita/Panasonic does also and perhaps Sony.

This could result in a $1000 CD player that sounds like a $30,000 CD player.
This is round-about way to get the signal reclocked. Its not available as far as I know.

There are two better and cheaper scenerios:

1) use the clock in the transport and transmit I2S to the DAC. You can do this for instance with PWT to W4S DAC2.

2) add a reclocker to the transport by inserting in-line. Then you are using a good clock, maybe better than the transport. Still S/PDIF coax or Toslink output to the DAC.

Steve N.
Empirical Audio