Bricasti OWNERS ONLY:
The Bricasti web site says “The MDx was implemented in production on all products starting January 2020, and is now available for upgrades. In keeping with our upgrade philosophy, all past D/A converter products are eligible for the MDx upgrade including all versions of the M1, M3, M12, and M21”.
I asked Bricasti its explain how this applies to my Bricasti M21 DAC. They said "An updated MDx will gain me nothing sonically. The newer revision is solely for the implementation of the new graphics display and IS2 for the M19 Transport. The M21 is identical sound-wise”.
If you have questions, please call Bricasti Customer Support for advice.