Schiit Lyr and Valhalla both look good. I am really anticipating the big expensive tube headphone amp they have in the works.
Here I have a Darkvoice 336SE and a Loxjie P20.
To my ears, the Loxjie is pretty transparent and a great value. I am guessing it is buffer + op amps, but I haven't looked into it. Amir said he had purchased ome for testing a while back. I am hopong he reviews it at some point.
The Darkvoice is wonky and I pretty much only use it with HD6XX and cheaper cans because it pops and zaps and cuts in and out on one channel and I am afraid it will fry something. It is a fun piece of gear. Nothing special with Clear, but really seems it bumps up bass on my high impedance cans. (HD800s and 6XX here.)