I’m still using the (ancient) Squeeze system (lyrion.org these days). Default setup for new things are a raspberry with a DAC or digital out (picoreplayer), feeding into active speakers. It’s open source, just works, with plugins for almost anything and has all the multiroom sync etc. You don’t even need a separate server unless you want to, just add some disk to one of the raspberries and let i be your media server.

Almost. -k is to supply the passphrase directly, while -kfile does what OP believes -k does. That’s why it reports “bad decrypt” as well.