What DAC upgrade made you say “DAMN, that sounds SO MUCH better than my last DAC”?

+1, @jjss49 

Exactly! I’ve asked OP to reveal his system and budget for DAC. No answer yet! I am willing to bet majority of recommendations here are not even pertinent or far off from his consideration :-) 

A short money upgrade can be buying a linear power supply for any of the less expensive 5V DACs that come with an inexpensive wall wart. I got a pretty good one on Amazon for about $85 that made a significant improvement over the stock supply that came with my Schiit Modius. 

@chorus, well I'll mention Audio Note.  I was happily using a Border Patrol DAC in an otherwise AN system, and was happy with the sound.  Switched to an AN 2.1x Sig. and the difference was amazing.  It will only do CD quality sample rates, but the improvement in layering, decay and dynamics are very obvious.  Couldn't be happier!
@Pengun, switch to the Denafrips Pontus or Venus, and use the Pi2AES I2S output for a real upgrade in sound.  It certainly makes a difference going into my PS Audio DSJr as it has the I2S connection.  

The PS Audio Direcstream DAC. I cant even remember what I was using before it. It even gets better every time they have released software upgrades, which , by the way, are free. I highly recommend this DAC.

I have been listening to a recent purchase of an Esoteric K-03XD for not quite two weeks and am (coming to grips?) with its sound. It doesn’t sound like a SACD/CD player in the sense that I’m familiar with and it doesn’t sound like a turntable. As a "died in the wool" analog person that listened to digital music as an afterthought (used to listen to digital as an afterthought), has in the last few years realized just how good digital sound can be and I’m now at a crossroads. Just one example of the kind of music making this player produces is a rip of a Patricia Barber recording of "Blackbird" that I can only describe as the wettest cover I have ever heard. When I mentioned this to the seller the other day , he laughed and told me a wetter sounding recording of new music by Barber is on its way. A pile of CD’s that I was going to dump for what I thought were bad sonics, I now have a renewed interest in. I will be buying more used discs at local second hand shops. More fifty cent discs and less $135.00 plus vinyl. I’m getting older and getting up every seven minutes to change an lp is not what I’m interested in doing much of anymore. In a way, like purchasing a Degritter, it makes my life better by making it easier to enjoy my music and simplifying the process of doing it.