I have both the AQ Dragonfly and the TEAC HA-P50 portable headphone amps/DACs
the TEAC is better sonically BUT it’s a LOT more money (.....like 3X......). For yeoman quality perfomance on a budget...the AQ Dragonfly ...highly recommended
One thing that is NOT highlighted in the reviews below, is that the new "RED" vs new "BLACK" is very headphone dependent as to which you may prefer.
With my over-ear portable Master & Dynamic MH40’s the "new" BLACK had a deeper lower register and an incrementally better overall pleasing performance....and its cheaper! By contrast my portable BEYERDYNAMIC portable over-ear cans preferred the RED......Go figger.
The M&Ds are a better set of cans .......hmmmmm
in any case: