To drive what? If you tend to go with efficient low impedance high SPL/V headphones/IEM's you are better with a deacent smartphone not cut a lot and able to give 500 mV out, if you are in mid efficiency and impedance tire then a DAP or smartphone that can give 2 V preferably still unbalanced. If you want to drive high impedance low efficiency obviously more but don't use gear that's not meant to be portable as it. With smartphone in the middle and as player you have software DSP capabilities advantage and streaming services support of course and most of it works and over BT so you might also go for a deacent budget LDAC BT small receiver with a deacent DAC and such can be found for as little as 50 $/€ this day's. Of course replaceable batteries are ancient history and if you want one that doesn't pull much electricity and give 2 V or close so that battery life is good then something based on CS43131 DAC.
