I would echo @dne statements, I have owned all 3. I could not tell a difference between 2 and 3. From 1 to 2 was a massive improvement for me. Allowed me to go direct to amp and sell a preamp. I think a preamp is still better but I needed the cash at the time and the 2 came to the rescue.
Benchmark 1, 2 & 3
Has anyone compared these DACs that can comment on the differences? or made upgrades to the newer model? I read through the Stereophile review of the 3 which kinda implies there is not much of a difference between the 1 and 3. Any help appreciated.