As ever, that is an excellent review. Thanks for taking the time to write it.

Going up in price to $1000-$1500, what would beat it?

To powerlifter450:
I think the Burson HA160D beats it. There's a whole lot more out there. I think Project86 would highly recommend the Anedio D2. What is going to be your primary intended use? DAC, pre-amp, head amp? Or maybe all the above? What kind of sound do you like?

Warm.n musical. I think.this pairs well with my LCD2 rev 2. I've owned this for about 3 months now. I love the built in pre amp. I feed it into my Lyr.

Warm.n musical. I think.this pairs well with my LCD2 rev 2. I've owned this for about 3 months now. I love the built in pre amp. I feed it into my Lyr.

I think the Tube DAC-11 definitely satisfies that desire for warm and musical. Your headphones are very revealing so beware of some other DAC/amps that might be tilted to "too much detail"....perhaps a bit of a misnomer, but take for instance the Benchmark DAC-1 or W4S DAC-2...by all accounts, decent gear but in the wrong system can sound overly aggressive and strident. I think if you lean towards warm and musical, you would not like either the Benchmark or W4S. Try those out and I think your ears will tell you pretty quickly.
I think stick with the DAC-11 and try some higher end tubes and see where that goes......there should be no regret in owning a great performing piece of budget gear......
As mentioned before if you have not tried the Burson HA160D, it would fit in the "warm and musical" category...I think many have found it is a great pairing with the Audeze's, though I have never heard the combo personally.