Question about Yamaha A-S701

I am very satisfied with this amplifier. It has power and the sound is perfect in every register. The price-performance ratio is very good.
I have connected two floor-standing speakers (CANTON-Nestor 803) and a subwoofer (JBL- Arena 100). I can't answer this question because I only use the amplifier for listening to music.

no problem. simply put: to make less out of more channels is possible, to make more out of less channels is impossible (except maybe virtual surround). an optical/coaxial digital signal is then processed accordingly by the D/A (digital/analogue) converter of the amplifier, an analogue signal, via the Cinch, is already processed in the player. Both are possible. the choice then falls in favour of the device with the better D/A converter. for example, with 5.1, the .1 stands for subwoofer. but if you don't connect one, the bass is simply distributed to the existing speaker set-up: e.g. 2.0 (2x front), or 5.0 (front,centre,surround).