What the Best Dac have you heard or owned. How could you tell it was that good.

I have not heard expensive dacs in my system but my modded PS Audio DSD sounds good for a $3500 dac. I experienced my dac improvement with added mods and now fully upgraded with APS nickel transformers, VOCM mod and analog power supply board powered by a Keces P3 with a Neotech 20ga silver dc cable connecting Keces power supply to power supply board in dac is the best sounding dac in my system so far. All that said I have not tried a lot of different dacs in my system.

The timbre, impulse and transient information coming out of my Ayre Acoustics QX-5 Twenty ($15,000) with L5xe is fantastic. Horns, voices or anything else in the midrange sounds rich, relaxed and has information around the notes normally missed in dacs such as the Bartok Apex ($20,950) which I sold. The bass with QX-5 is incredible as it has texture, extension and detail galore without sounding bubbly, bloated, unnatural or lacking. The QX-5 has made me a better listener because now I know what I was missing. Compared to the competition, the QX-5 should cost 2-3x as much. Happy listening!

The best DAC I have heard is the MSB Select.   I have not heard the Nagra, Wadax or Playback designs.  I have heard all the others mentioned in this thread and it is not even close to my ears.