I too, have a Cambridge Azur, but not the 840.
I've compared my Ultra DAC with my Cambridge Azur for a long time, and now the Azur is being used in my second system.
The reader's description on the Azur is very accurate and I couldn't have said it any better.
I have two British designed CD players, the AMC 8B, and the Cambridge Azur, they both sound very similar, and both cost me $200.00 each during sale price.
They both have the edge on the high treble than the Ultra, therefore, give a more 3 dimensional perception to the listener. But the Ultra offer more bass, better midrange details, and more natural sounding vocal. The British designed CD players have that too, but not as much.
If I had compared these CD players to the Ultra DAC in a stereo store, I would have picked the $200.00 player in a heartbeat due to the huge price difference. But I bought the Ultra DAC as an upgrade and wanted something better, and I've achieved that.