I would like to continue using an existing stereo system (amplifier, CD, tuner, and passive speakers) and feed it into the sonos system: - thus listen to music from the CD player/tuner on all sonos speakers and the existing passive speakers. - and have all the sonos functionality (multiroom, internet radio, spotify..), listen to all sonos speakers and also to existing passive speakers, and control them via the sonos app. -> is this possible? -> how is this to be wired, to which outputs? as i understand it, this requires that the existing amplifier has a line-out (OUT jacks output audio signal, cinch).... right? thank you