Just put in a newly installed MDx board in my M1. The M1 has always been stunning, but I’d say the MDx brings extra precision, yielding impressive and clean dynamics, to the table. Clean clear but without any hint of brightness or glare.
Reminds me of an an experience I had years ago. My first 2 CD players- first Technics then CAL did some things well, but the music didn’t “make sense”. Vocals were irritating. By 2000 I picked up a meridian 508.24. While dynamics were not its forte, it was the first digital player that made sense and where I liked the vocals. Here, the MDx makes total sense.
Removing the old board, while taking photos, and installing the new board, was easy. My initial mistake was not removing the lock washer and nut from around the S/PDIF input.
These are the tools you need- torx driver for the lid, Philips screwdriver, and a 5/8” driver or wrench for the nut on the S/PDIF (I used a 16mm with masking tape inside). A small flathead screwdriver is needed (or at least extremely useful) as well
cost was $700 plus shipping. You have to return the old board.
Essentially, you get an entirely new digital section. Power supplies and analog boards, which are mature technologies, are untouched.
The only thing so far that I see you loose is auto detect of input source.
If you have an M1 and are ok with the cost, this is a rock solid choice.