Holo Audio May DAC

break-in is going to take a while

I think break in is a valid exercise for mechanical things, like phono cartridge suspension, speakers roll-surrounds, maybe even laser suspension etc etc.

But with electronic devices dac, pre, amps etc I believe if your not getting "off on it" after 10hrs, which by then even the most stubborn of caps have polarized/formed properly, then your only going to talk your self into it waiting for 500hrs.
BTW: Also, nothing will measure any different from 10hrs to 500hrs.
But compliance in the mechanical things above do. 

Cheers George

As break-in goes, I heard great things from the May KTE right out of the box.  Once I got 20-30 hours on it I thought it sounded slightly better (10% improvement?).  Beyond that it sounds great and I haven't really thought much about it.  I doubt I have more than 200 hours on mine so far (I spend a lot more time listening to records) but I am still very happy with the May.  
I have not heard the Audio Mirror DAC, but have heard good things about it.  Either way, the May DAC holds its own among the Super DACs, and for me this is enough.  As I mentioned I mainly listen to records, so naturally I prioritize my efforts around my analog set up.  If these priorities change at some point, I will likely pursue DACs that cost more and perform more highly than the May.  
Happy listening!
Peter

George, agreed that you know the basic character after a day or two. 

That said, I've had two experiences that have convinced me that electrical break in is real and can take a full week or so. 

I had a Pass Labs xa30.5 and decided to get their int30a integrated with the same exact amplifier circuit. Two days into listening (48 hours of play time) it still sounded worse than the original amp. I was told they would sound identical after a week by renohifi and they were correct.

I also built my own First Watt f4. Eventually I decided to build new boards with the highest quality parts available and when I excitedly powered up they sounded way worse. That remained true for a couple days. After a week of 24h/day play it became the significant upgrade I'd planned for. 

Termi vs Termi +. Had them both in my house side-by-side.  I so badly wanted to like the plus better.  Latest model, oven controlled clock, has  to be better right??? I kept the Termi.  The plus was great, a slight, very slight, bit more “drive” behind it. Almost like digital equalization slightly tweaked. I didn’t find the change necessary or better, just different. Also, when listening to very delicate detailed highs (“My Foolish Harp” Isabelle Olivier) the Plus couldn’t quite match the  delicacy of the Termi.  Forced my wife to listen too (yeah, I know) she also preferred the terminator over the plus.  Tried both with and without the Gaia.  The Gaia provided a barely discernible improvement to both—kept it. Toying with trying the May but with no trial period, and being extremely satisfied  with Termi I just can’t bring myself to do it...Yet. 

Roon Nucleus+. Mark Levinson pre and monos. B&W 802D3s

@73max, how many hours on both? With such a close sound and the Plus not handling delicacy as well as the standard, sounds like just a break-in thing. When I had a Termi, delicacy and final details is what took the time... Not saying your observations are not true, just aways a chance with something ‘new’. Especially since they’re so close.