USB DAC Dumb

Thanks for the reply.
I haven't purchased the CD player yet.
Of course I will buy one with a digital output.
To keep costs down I'm planning on buying a older carousel player.
The DAC in my headphone amp is modern and reportedly very good.
So, how to use the USB to the digital out in the CD player?

Unless there is such a thing as a coax or optical to USB adapter, you won't be able to.  Have you looked for that?

Mahler's point is Question 2 in my previous post.

D99, Your CD player probably has a SPDIF output.

Sending SPDIF Input to the DAC's USB input cannot be accomplished by a simple cable type of adapter/converter

You will need an electronic converter. 

USB - SPDIF converters are common, but I do not know of any SPDIF TO USB converters

Are you sure your amp does not have any other type of digital input? Such as optical

What amp do you have

Check out the Mutec-3 or even less money the Mutec-1.2