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

As the title suggests, what was your overall system and DAC at the point where you bought only a new DAC and said “DAMN, that sounds SO MUCH better than my last DAC”?

I’m a novice and so many people talk about improvements from new equipment as if they were only listening to varying degrees of static until they bought more and more new equipment which added up to them finally being presented with music. It’s like Salome and the seven veils. But when does the last veil get peeled away? 

So what system did you have and what DAC did you swap in that made you say “DAMN!!!!”?

I guess I’m looking for night and day differences, not gradual progressions……