It s about internal clock, reduce jitter and electrical noise, and good stable power supply.
This is also for a DAC, and here the filtering is important.
Digital signals are in fact transported in an analogue way and it is important how good this is done.
the link below talks a bit about that:
View: https://www.youtube.com/watch?v=AzJEvGWWtqg&list=PLMbsmejHnP8FqbhDskGnwKW7dPQjRWIVm
I also have a link of a review from your streamer from this channel, very interesting with some measurements also.
View: https://www.youtube.com/watch?v=lmw5GRJDRqA
The reviews of your streamer and amplifier are generally very good/good. The wii does a very good job for the money (which means you should spend at least a 1000 to make a audible step forward) .
I found a review with measurements of the amplifier on ASR, their conclusion mainly is that the DAC is average..... Before that I thought, you have a great hifi set up, what s there to upgrade. It might be an idea to audition a seperate DAC (instead of the internal Cambridge DAC). Or indeed another amp with internal dac.
With your budget and those reviews in mind, the first two things to consider are the DAC and the streamer if you really want to upgrade. (though you say it sounds good....) If separates, both above the 1000 dollar/euro .
This way you get the source right.
What helped me is to look in reviews of hifi and read what details they hear in music. for example in this list on what hifi:
https://www.whathifi.com/features/10-best-songs-to-test-your-speakers
and for example, one part describes to test bass of you system:
"
To test bass control
Massive show-off Thundercat (Stephen Bruner) delivered one of the more critically acclaimed albums of 2017 with
Drunk. And on
Uh Uh (a brief but exhausting exploration of the six-string electric bass guitar), he plays with such frantic virtuosity your speakers have no hiding place.
Bass extension, speed, tonal variation, and attack and decay all get the sort of examination that speaker engineers dread. What’s required here is well defined, well described variations in note tonality and intensity. In the right hands it’s a remarkably athletic piece of playing, but in less capable care it’s just a low-frequency mess of overlapping information."
There are a lot more tests and reviews with song descriptions. This way you can discover where your set shines and where not. And find out what is there to upgrade. Also try to match your equipment.
There is lean-sounding equipment and "warm"sounding equipment and so on. Matching a lean sounding amp with lean sounding speakers for example may result in a too analytical sound which looses on musicality, for example. Lots to discover...
This is a review and detailed measurements of the Cambridge CXA81 MKII integrated stereo amplifier with digital inputs (USB, Toslink, Coax) and Bluetooth. It was kindly drop shipped by a member and costs US $1,199. There are no visible changes from the original CXA81 I tested. I *think* the...
www.audiosciencereview.com