its a little bit diy.very easy.
open up this logitech and de connect the in built amp.
connect the speakers from your marantz..
be cautios not to increase vol very much..
imo these sepakers are not a true compliment to maratnz or alike..this may harm the maratnz in full vol...dont know exactly..i am not expert
it will work btw guaranteed..
i did this in my student days to a 2.1 set speaker set up when it stopped working....and i opened it and disconnected the in built amp and connected the speakers from a cheapy multiplayer speaker level outputs