You are indeed '100% correct' that what you have stated.

On the other hand, it's been my experience that some sound cards are not exactly clean (analog outputs); I have heard a variety of spurious low-level noises that come from the analog outputs of some sound cards. Thus, your zone 2 signal, if coming from the analog output of the PC, may not necessarily be all that free of noise - but then again, it might, depending upon the card and its immunity to noise from the PC chassis (your mileage may vary).

Since the adapter you mention is designed to provide analog outputs I would definitely recommend that approach as this would get around the problem of a potentially less than ideal analog section of the PC's sound card. That is, the adapter you cited does the D/A outside of the host PC's chassis. It's way cheaper than the NAD device that I mentioned and effectively provides the same degree of functionality (minus the wireless capability). For $3.19...how could you go wrong?

Anyway...good find and a great suggestion as a work-around for the (sometimes) noisy analog section of a sound card.