Do you recall "instant improvement" from your first stand-alone DAC ?

My first DAC was one of the first the Audio Alchemy DACs.   It was a step up from the Sony player I was using.   

My first DAC that really sounded good was a California Audio Labs Alpha DAC with Delta transport.  That was an expensive DAC for a young audio enthusiast,  it was $1500 in 1993 .   Equivalent to over $3k today. 

I've had a number of DACs since ,   my current DAC is a Lab 12 DAC 1 Reference.  Beautiful sounding DAC that i have no intention of replacing anytime soon.  

I'd have to try something that really blew me away before selling the Lab 12. 

Yes!  At every DAC upgrade I heard more resolution, more life, more engagement.  My upgrade path went Classe internal DAC > PS Audio DS1 > Auralic Vega G2 > Mola Mola Tambaqui.  (All using internal bridge).  Then I got a decent streamer, Auralic Aries G1 an that made things more lifelike, breathing air into the sound.  Everything does matter, and power supplies (if needed), cables, and tweaks to digital front end all add.  With your Tube gear @foamcutter, I would suspect a highly resolving DAC would be amazing.

@soix nailed it…

“fuller, richer tonality, more refined treble, and an expanded soundstage”

Having owned Merason’s DAC1 MkII, I would also expect you might hear improved bass.

DACs that have provided a noticeable improvement to my system have made the music sound more natural and less digital.

I would expect the Merason to immediately sound more harmonically correct with better performance at the low and high ends. However all upgrades carry the risk of unintended consequences, be prepared that masked weaknesses in the streamer may be exposed with a better DAC. The main difference between a $1k and $4k streamer IME should be more sophistication in detail and better resolution of background instruments. My first separate DAC years ago was a Dlink III and it was enlightening on how DACs were important.

Without a doubt.  My first dac was manufactured by Musical Fidelity and it made an immediate improvement to my Sony ES cd player.  I later purchased an MSB Link Dac III and there was a noticeable improvement with that dac as well.   After that, I tried a few newer dacs (Jeshelli) and I didn't notice as mush difference.  I just received a Denafrips Ares II / with a Cambridge dedicated Transport and haven't had it long enough to judge how much of a jump I'll get.   My experience though is dacs make a difference for the better.