Transport/DAC upsample question

BB, a "transport" only reads data contained on a disk. It doesn't sample (upward or downward). The D(igital) to A(udio) C(onverter) does that.
So, no problem. All you need is an output fm the transport (usually labeled "digital out" on cdp's). Cheers

THANK YOU!
As simple as it was for you,Greg,for me it was valuable.

Typically the DAC does the upsampling. This could be a standard upsampling frequency, say 24/96 or 24/192, or some DACs allow you to select the upsampling frequency

However, my North Star transport also upsamples. Using the XLR output I can set a switch to allow 24/96 upsampling. Using the I2S output I can set a switch to allow for 24/192 upsampling. If I do this, then in XLR mode I can upsample the 24/96 signal to 24/192 at the DAC (which also happens to be a North Star), or with the I2S mode the DAC just accepts the 24/192 signal and passes it through.

Hey BB,

The answer to your question might be somewhat manufacturer dependent but one thing is certain, the interface between the transport and DAC will determine what sample rate is being communicated. In the most likely situation, the transport will be connected to the DAC with a S/PDIF connection. This Sony/Phillips Digital Interface is defined as a 44KHz 16bit data interface. Even if you are using a balanced interconnect, the data interface is the same. Some manufacturers have proprietary interfaces that use a different data communications interface. These interfaces might support higher data rates and the transport could in this case do some up/over-sampling. In any case it is most likely that the up/over-sampling is done in the DAC.

The Theta Digital web site has a good article on up/over-sampling at:
http://www.thetadigital.com/upsampling.htm

Hope this helped,

John