In the past, I've struggled to be able to stream music from my Linux Laptop. So I've always done it from an Android devices instead (tablet or phone via
BubbleUPnP). However, I thought I'd have another hunt round and
found a solution. Install
foobar2000 via Wine and then add the
foobar UPnP renderer component.
With everything installed, I can go to file > preferences (ctr-P) to open the Preferences window. Then go to Playback > Output, and in the Device dropdown my Marantz NA-7004 is listed. I select that and the music from my laptop is streamed to the NA-7004. Excellent.
There is another
component that lets you pull music from UPnP servers. With that I can browse my NAS (network harddrive), select and add music to the foo play list.
It's not pretty - but it's working a treat.