What is the best DAC ever made?

Dev, you right! AA had stock tubes and cable was just ordinary, but we used the same for Berkeley.
I believe that we can say something about component only in compare with another. Or sometime we say in compare with something we heard before. Like, best I've ever heard. And the question is what you really heard? Yesterday I said Berkeley is the best, Today I'm saying dCS is the best, may be tomorrow I'll find something better and it will be my new reference. This is all about your personal expirience, I believe.

i am still enjoying my Zanden every day, and feel no need to look any further, despite knowing (as with all things), it too will be surpassed.

I don't know about the "best DAC ever" but the Tranquility SE pretty much maximizes my needs and especially my wants. Before I tried the Tranquility, I had no idea what a well-engineered and manufactured DAC could accomplish. And I was very skeptical of the claims made for the Tranquility. Now I see why the early adopters were ravers!

I have it setup with a 2010 MacMini (8GB ram) and Pure Music with a 1TB Oyen MiniPro firewire HD to store the files and RSAD Alethias USB from the Mini to the Tranquility SE.

The Tranquility is a consistent pleasure (and often jaw-dropping) for ripped files (AIFF) for streaming audio.

The customer service is amazing. Always interested in making the most of the system you have.

I neglected to post that I now have the Weiss Dac202. It is very impressive.

last years i have owned , berkeley alpha, weiss 202, AA tube dac SE, and tried dozen of others dacs.. and now landing with an Diy AudioNote dac 3.1 . it is the first one i can listen hours and hours like my other analog stuff..