Whether you need a discrete sound card depends on how many inputs you have on your multizone setup. Win 7 will use one sound output (e.g., HDMI) and all other outputs on your motherboard can be managed by Casatunes. There are many choices of motherboards with HDMI, coax, spdif, and 7.1 (I.e., 4 analog outputs). With a separate DAC, you could use the coax and spdif to give you additional analog outputs.
My setup is the following:
- Intel SB w/on-board HDMI and 7.1
- generic 7.1 PCI sound card
2) Emotiva UMC-1 preamp
3) Nuvo Technologies Grand Concerto (6 audio inputs)
- HDMI to preamp for local room
- preamp zone 2 output to input 6 on Nuvo
- CasaTunes manages discrete sound card and outputs to inputs 1-4 on Nuvo
- CasaTunes manages onboard 7.1 and outputs 1 to input 5 on Nuvo
My old Russound only had 4 inputs so I did not need the discrete sound card. With the Nuvo, I got a cheap 7.1 sound card off eBay.