For those who own MK1, the APS/VOCM mod is really a better bang for the buck. Comparing the unmodified MKII with the modded MK1, I can concur that the latter sounded better than the former. The MK1 although is getting old, is a mature product with a pretty stable firmware.
Modding the PS Audio Directstream DAC MK1 and MK2
I would like to continue discussing all the mods we have created for these two DAC's as it seems PS Audio is no longer allowing discussions about them on their forum.
For reference here is a link to the closed discussion.
https://forum.psaudio.com/t/modding-the-directstream-dac-mki/2680