Which model?

Hi. I have bought a second hand directstream which was upgraded to. The instructions say "perfect DAC Mk 11 upgrade kit. This is an upgrade from MK 11 our to a MK 11.
How can I tell ?

It’s easy to tell between a MK II and a DSD based off the firmware. If it’s a DSD, it’ll have a name like Redcloud or Windom for the firmware. If it’s a MK II, it will have a number representing the firmware like 3.0.4.