Digital system upgrades

I think you already have a very good digital setup. I’ve heard the Qutest and it’s an excellent DAC. I’m not sure swapping out the streamer or inserting a reclocker would net you anything since the DAC’s USB interface measures well. If you’re dead set on adding to the digital chain, the M Scaler would be my choice among the options you listed.

You might also want to experiment with EQ if you can. There’s s a slight dip in the on-axis measured response to the Sonetto that’s centered in the middle of the presence region (~2.7 kHz). Boost that maybe around 4 dB and see how that sounds. A Hi-Fi News review also showed a large rise (~5 dB) starting at 6.5 kHz all the way past 20 kHz. You can cut that region and see if that changes the sound for the better.

https://hometheaterhifi.com/reviews/speaker/floor-standing/sonus-faber-sonetto-viii-speaker-review/

https://www.sonusfaber.com/wp-content/uploads/pdf/reviews/2018/Hi-Finews_Sonetto%20Review_Nov2018_UK...

@yage Sonus Faber Sonetto VIII

What speakers are in your system?

I’d do a trial of the Audio gd R8 DAC from Underwood HiFi that’s $1000 under your budget.  Not sure how you’re getting the signal to your Zen, but with the remaining funds I’d consider adding something like an Optical Rendu that also can also provide the benefits you’re looking for especially if you’re currently using a simple, wired Ethernet connection.  Best of luck.

@soix just looking to take my digital a step forward. More openness and bigger soundstage is always welcome. Was thinking of moving up to the Innuos Zenith

Depends.  What types of improvements are you looking for?

Sorry forgot to mention about $3000 budget