Thanks John and Gonk. I think I will use the tape out and have the switch as a back up plan...good idea.
Zone 2 from the 990 will only go to the great room speakers. The tape out or audio switcher will feed the Denon. The Denon will actually be feeding a set of speakers on the deck (A) and a set of speakers on the patio (B). Zone 2 from the Denon will feed an old Yamaha 2 channel receiver (eventually to be replaced) that goes to a Niles distribution/IM volume controls for speakers in the kitchen, master bedroom and master bath. So theoretically, with an analog feed from a CD or music station on the cable box, I'll be able to have music in seven separate locations. Different sources are not really needed.
Whew...complicated? yes...why?...because I can or why not?
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Growing old is mandatory
Growing up is optional