My advice is tread lightly....
I picked up some headphones and enjoyed listening through my preamp.
Then decided to try a headphone amp - the Chord Mojo2...it was a drastic improvement. Oh, yes you guessed it then I listened to a 'high end' non-portable headphone amp. And now I have two headphone amps - 1 for travel and 1 for the bedroom. I'm happy listening to them. But if I know the type of rabbit hole I was going down I might have joined another wine club!