Unlike previous generations of our AVR’s the Concert AVR-7 and 9 CAN send signal out the RCA Zone 2 pre amp outputs from a digital source, not just analog.
It is good to note since the Zone 2 output is analog, the AVR WILL downmix the digital signal to be compatible with the analog output.
For example, if Zone 1 is receiving a Dolby Digital signal via HDMI, the AVR will convert that signal to a compatible 2 channel signal which would be Dolby Surround to send out the Zone 2 output.
This is true regardless of the multi-channel digital signal. For example, if the AVR is receiving a DTS Master HD signal, it will still downmix to a Dolby Surround signal to send to the Zone 2 output.
Because of this feature, this means that any higher resolution format (Dolby Digital, Dolby Atmos, DTS HD Master) will be disabled when Zone 2 is feeding from that input.
Concert AVR product pages