Since the round remote is IR and both devices can be controlled by a Beo 4, I would assume that the remote uses usual B&O IR commands. Therefor both remotes would be the same and allow at least volume control to Audio devices.

Thanks I've ended up with one of these remotes in a package of B&O stuff, which is why I ask.  I don't have a Beosound 8 or Beoplay A8 and have no intention of buying one, but it's a nice little remote, and if it would have controlled my other equipment, I would have kept it. However when I test it, it does not control my Beosound 4. Since I added the original post I have done the 'phone camera test' to check that the IR LED is blinking when a button is pressed, and it is, so I would have to assume that it is working, but it does not send the same signals as a Beo4. Shame, but not a major issue for me, I'll just sell it on eBay.  Thanks for your help.

Just for info - since posting this yesterday I found

Location: Liverpool

My B&O Icons:

BeoCenter-9500.png

Beoremote-Beo4.png

Beovox.png

Beovision-11.png

Beotime.png

Beosound.png

Beosound-Moment.png

Beosound-9000.png

Beosound-5.png

Beosound-4.png

Beoremote-One.png

Beoplay-Portal.png

Beoplay-EX.png

Beoplay-Earset.png

Beoplay-A2.png

Beogram-400x.png

Old enough to have gazed at classic B&O HiFi in Plumbs shop windows in the 80s...

There is a little info in this older thread, but it does not seems to be conclusive 

Location: Denmark