I'm almost embarrassed to have to be asking this question as up until now I've known everything about sound (haven't even had a setup without surround since 1989), but after looking through options I'm just a bit confused. What I would LIKE to do is replace my current 7.1 receiver (which doesn't do Atmos) with another receiver that does do Atmos but WITHOUT the use of any additional amplifiers! If I'm reading the instructions for some of these correctly, you need an additional amplifier or more to run the extra Atmos speakers, OR you can disable the two rear-surround channels and play the Atmos channels through those instead. I of course want ALL channels to be working and not have to give any of them up. (Currently Atmos sound tracks play as 7.1 on my system; I would assume that they're intended to be heard that way with additional speakers for Atmos.) Some have terminals to hook up 9 speakers, but it appears that for Atmos it won't actually put sound out through all 9 of them at once, again forcing you to either disable some channels or use another amplifier to run the Atmos speakers. I have limited space right now (limited funds also) and it would just be a mess to have more than one "box" powering the sound. If it's not possible to do this with just one receiver/amplifier unit that can drive all the speakers, then I might just have to forego Atmos for the time being.