I recently had a chance to briefly compare the M51 and the M12, one evening after hours in a Hifi store in Denmark. Quite interesting experience.
I only spent perhaps 1 hour to compare the two, so the variance of music etc. was minimal and the impressions remained only that - impressions.
I had no expectations to the differences between the two, or how they would behave sonically. My personal perception was that the M12 felt as having a higher resolution in its conversion compared to the M51. Whether specs will support this, I have no clue. The "air" around the notes (lets just call the significant sounds "notes") in the music was more pronounced with the M12 and the notes themselves were more sharply painted/defined than with the M51. This allowed me to feel that I had more "access" to the nature of those sounds in the music I was listening to.
Perhaps as a consequence, ambience in the sound stage was also easier to decipher, as the sounds it was made of were quite a lot clearer with the M12 than the M51.
The M51, by contrast was a tad warmer in its sound, seemed a bit "fuller" in its bass reproduction - while retaining very good definition of the notes. Simply not as defined as the M12. The ambience was harder to decipher, though. Not hard-hard, but still a win for the M12.
For lower quality music productions, the M51 was more pleasant to my ears than the M12, especially when played at very high volumes. The M51 did this very well in my opinion.
Both DAC's were really good, I think. Surprisingly good actually. What I haven't yet described as part of my impression is, that I also compared the two to another, very well known and often referenced DAC, which I have owned for years. They both faired really well - and both better overall - than that one, which I currently own. Meanwhile, I'm selling that one at the moment, so I'll only lift the veil on what that is, when I've sold it
I loved the clarity and brutal honesty of the M12 and really cherished the tad warmer sound of the M51, as it still retained much of the detail of the M12. I am strongly considering purchasing the M12. In addition to simply being an extremely forward-looking and upgrade-flexible piece of hardware, I think the sheer clarity and insight it provided will win the day for me.
However, I need to get back to the store at another point in time for some more in-depth listening. Especially when I've sold my current DAC and have the money to go forward. I'll report back to this thread upon doing so.
Best of days to all, Jon.
