For digital, removing noise from your system in the form of EMI or RFI really helps produce smoother sound. You've taken the first steps by getting the Blluesound Node streamer. Other steps that can help are:
- Turning off the Wi-Fi receiver in your streamer and using an Ethernet cable. One way to use an Ethernet cable without running cable all through your house is to use a Wi-Fi extender to create an Ethernet access port which then connects to your streamer via an Ethernet cable. That at least gets the Wi-Fi receiver and the RFI it generates away from your streamer.
- Local files can sound better than streamed files.
- USB cables matter. I'm using a Stordiau Phasure Lush.
- An Audioquest Jitterbug noise filter on the USB output of my streamer seemed to make a positive difference.
- For streaming, the fairly inexpensive Supra Cat 8 cable works well in my system.
- My latest upgrade is an Audioquest Niagara 1200 power conditioner. That seems to have taken out any remaining harshness that was causing listening fatigue after several hours of listening.
I also rejected digital audio for a long time because it caused listening fatigue for me. From 1989 to 2021, I didn't have any digital in my home system. I would stream Qobuz using my laptop or phone and headphones. That changed during the pandemic when I was doing a lot of music listening while doing work and I started building up a digital source for my home system.