My CXA81 didn’t come with the antenna for some reason, so I had to find this spare part. Glad it finallly worked out. I have been playing various kinds of classical music in FLAC format via my phone and it sounded great, albeit with a very slight metallic tinge.

The SUB connection I used prvioulsy was unreliable. Moreover, the volume could not be controlled from my Mac. This bluetooth connection is, surprisingly, much more reliable and offers volume control from my Mac.

Spent extra on the amp for Bluetooth, debating whether it's any kind of upgrade without the antenna. My 90s pioneer amp is miles better.