Michele wrote:
I was told I could purchase the Beosound Core and connect them with the Powerlink cable so I could "transform" my MK1 into MK3.
Well, all you are doing there is connecting to the Core and it's sending the audio through a cable. The MK1 isn't becoming a MK3 in any way, really. You're just sending an audio source. But, if you want multi-room, it's a good option.
Personally, I've never quite understood the need for multi-room. I can't think I've ever needed my speakers to play the same audio across my house as I walk around it. I either listen in one room or move the audio with me. ie. I'll play through an A1 or similar portable device and simply move it on to my roof terrace.