I would suggest that the Wadia 922/931 with modifications from Great Northern Sound belongs towards the top of the list. It has taken me over a year to begin to appreciate what the Wadia DAC does, and I remain amazed. For me, the Wadia is such an essential part of a system that brings me into a performance with the greatest musicians. The Wadia will not add anything to the performance, but extracts all the detail about the music, the technique, and the venue. The Wadia is absolutely realistic when it comes to dynamics, image size, detail, and soundstage. It does all this without exaggeration.
As an example, I am a bit of a pianophile, and I like to hear the differences in technique. With Richter, he was a big man and used his entire body to play the piano it can be quite aggressive and even violent. Horowitz has a bell-like quality to his right hand that remains clear even at high-speed. Bolet coaxes notes from the piano, Pletnev lobs notes from the piano each has a characteristic intonation. I am now listening to Schuberts Sonatas by Uchida. She is such a cerebral pianist, and can play with such light touch, tenderness, and beauty.
