How easily can you distinguish between different DACs?

DACs use similar standardized chip sets. So the differences will be in the analog conversion, which in theory is also a standardized algorithm. However, some manufacturers don't follow the standardization and do their own inaccurate conversions. According to the book Schitt Happened, Schitt used to program their analog conversion by ear. In effect, turning their DAC into an immutable tone control, which IMO is definitely not the purpose of a DAC.

Having been a programmer who has written conversions in other areas, I understand that there isn't anything magic about it. It's either as accurate as the standardized algorithm allows it to be or it's inaccurate. Which means you shouldn't hear a difference between properly programmed DACs.

True, looking at this as software. But ever subcomponents… resistor, capacitor, and turn on the circuit board… the distance between the power supply and all the other subcomponents, the resistance to vibration from the outside world makes a difference in the sound. So, any given chip set can sound very different given the circuitry and environment they are dropped into.

+1, @ghdprentice on implementation. I’ve heard some of the perfectly measured DAC’s and they choke the life out of music. 

It is necessary to have the good audio gear to begin to hear differences in DACs easily. Common audio gear like Denon, Pioneer, etc do not have the resolution to bring out the differences that we can hear.

If music is background then common audio gear is sufficient for enjoyment of music and most DACs produce decent enough sound.

But if you are really into music and listen to music as a main activity (not doing anything else and focused on listening to music) then it is worth it to seek out better audio gear and better DACs.

@mapman - the A/B test I did was not from two vanilla $500 streamers.  The actual SOtM streamers were both SMS-200 neo SE ($1000) both connected to a Sean Jacobs DC3 dual-regulated PS ($2000). Both streamers connected to an SOtM sCLK-0CX10 ($4000) (it has 4 outputs) itself powered by a Farad Super3 PS ($700). So, if using $ as a measure of quality each streamer cost around $8000.  This is a good piece of streaming kit. It should be capable of discerning differences between an expensive and cheap DAC, if they exist.