hi,
the output is gud but not smthng that will
jump at you.the highs are not tinny but not that pleasant either but the details are there.
so let me say that if u r someone who loves the yamaha sound signature on an avr or amp u can live with this but if u love a marantz type or more of a rounded warm sound signature stay away frm it.
i didnt pair it with any portable amp.i used my desktop,my phone and my marantz Pm6007 headphone output.
i liked the signature of my senheisser momentums more.though they too are towards the brighter side but the sound from the senns overall is not kind of flat to be precise compred to the ATH.
A piece of advice:-
if u can pls do try to audition the mezee neo 99 which is around this price.headphone zone will let u audition the headphone.i cudnt due to this pandemic and was a bit in a hurry to buy one.