The hardware version of M500 is the same as Ver.1.2 at the time of release, and I think there is no change to date.Because version 2 is the most current with the manufacturers best effort on this product that's why . Honestly if it didn't matter I'd buy a Stello Signature Dac2 from 2012 because it worked wonderful till it melted down from over heating
The firmware of the system was Ver.1.4 at the time of release, but has since been upgraded to Ver.1.5 and remains the same.
The firmware of the USB interface was Ver.1.5 at first, but has since been updated to Ver.1.07 >> Ver.1.08.
Which M500 is Ver2 you say?