Empyrean Headphones/Sennheiser HDVD 800 + 'what DAC'?

I have a good headphone amp in my DAC/preamp, but for portable use (with Senn HD650) I use a Dragonfly Cobalt and my phone, streaming Tidal. I think it sounds excellent, very close to my rack unit.

The Sennheiser is an HDVD- it's only a headdphone amp- but a damn good one.  It drives my Meze Empyrean headphones.

I used the Dragonfly Red for a while when I was getting started in HeadFi and still use it for when I’m on the move, but your system would benefit from a better DAC IMHO.   What are you using for a DAC now (if any), and what sound characteristics are you looking for and are most important to you?  

Doesn't the HDVD 800 already have a DAC built in?

I used the Empy (a warm headphone) with a Benchmark HPA4 preamp/headphone amp and a Benchmark DAC3B. It was a great combo since the neutral Benchmark gear matched the warm Empy. A used Benchmark DAC2 maybe available for under $1000. It sounds the same as my latest DAC3B (I had both before).