Apologies if I'm asking a question that's been answered already, but I couldn't find anything related (or making sense to me) after long searches. I'm a total beginner and don't know much about the field of electronics / sound, so apologies for such basic questions. Would really appreciate any help.
I've got a house with 2 zones of speakers - outside (2 speakers) and main floor (2 speakers). Both zones have in-wall volume controls by Russound (a turn knob with 12 positions, older version of ALT-126R). In my basement I've got 4 wires (2 for each zone) - one CAT5E and one with 4 conductors inside. I presume the latter is for actual sound, and have no idea what the CAT5 is for (they both are marked for each zone, so clearly there is a reason for it).
I want to be able to play music in those zones and for that, it seems, I need HiFiBerry AMP2 (I've already got RaspberryPi 3B+ that I could re-purpose). I've got a home server running Debian Linux which I use as a storage for my music. Ideally I want to have a way to control what's playing over some UI (web would work) via my WiFi - so, with a phone connecting to some App/OS. It seems there is a choice of such OSes - HiFiOs, Volumio, etc.
If someone could please help me answer the following:
- Is AMP2 what I need to drive my speakers?
- Can I use AMP2 with Russound volume control in between it and the speakers?
- I presume Russound volume control provides power to the speakers (since I can turn them off?), but maybe I'm mistaking. Would such setup not work with AMP2 (logically I think it shouldn't matter but I'm not 100% positive)?
- I've seen (https://www.hifiberry.com/docs/archive/connecting-power-supply-and-speakers-to-the-hifiberry-amp/) and am not sure what the "alternative power supply" is. Would I need that?
- I understand that this would be a stretch, but any idea what that CAT5 cable would be for?
Thanks a bunch in advance!