Loud 'crack' before song plays

From how you describe the noise, I think I’ve had similar occurrences with certain digital combinations. 
 

Next time you listen try and note if the bit depth or bit rate are changing between songs. If so, the noise might be the Node and Emotiva DAC adjusting to the change. 
 

I just use physical media right now so I don’t have the issue anymore. 
 

I can’t remember any of that with Tidal. Qobuz is silent. Good luck wid dat.  

Ripped SACDs are quiet.

I have a Bryston DAC3, which has HDMI inputs, and I can output the DSD layer of 

SACD from my OPPO 105.  I get the crack on SACD replay but not through the non HDMI inputs, or not through a regular CD played through the HDMI inputs.

I start my SACD with the volume turned down to zilch with the player paused and then increase the volume and hit play

Sounds like the Blusound Node is the likely source of the noise. Any chance you can borrow another streamer to try? 

I don't have this problem, but have a couple Raspberry Pi's (using either PCP or HiFiBerry OS) which is connect to my local collection and Qobuz thru an LMS server and experience nothing like you're describing. 

Ah, the joys of streaming!