To answer my own questions about the usage of Zone 2 with A4A in case it could be useful to someone else. I guess the same or similar logic can be applied to A6A/A8A and their appropriate zone configurations.
It turned out that Zone 2 output is controlled by the speaker settings in “Speaker” > “Power Amp Assign”.
When this one is selected Zone 2 is powered by its pre-outs
. No sound is coming from its speakers terminals. All amps are used for the main zone only. Depending on whether a speakers channel is set to 'Small'/'Large' or 'None' it outputs sound or not. When Zone 2 is switched on there is no audio drop out
in the Main zone.
2. 7.1/5.1.2 +1Zone:
When this one is selected Zone 2 is powered by its speakers terminals
. No sound is coming from its pre-outs. The amps for Zone 2 are assigned explicitly
to Zone 2 (when it is powered on) and they could be used in the main zone to power surround back or front presence speakers only when Zone 2 is not powered on
When Zone 2 is switched on though there is audio drop out
in the Main zone as the AVR has to reassign the amps used in the Main zone to Zone 2.
So, technically it is possible to power Zone 3
with A4A by using two scenes with different speaker configuration set for each of them. The only restriction is that sound can be output only to Zone 2 or Zone 3 but not both at the same time.
And I am wondering the exact same question about Polk Reserve series