[Arcaneex]

My budget is 50$, looking for a good amp ( portable) to power up DT770 80 ohm. Source is a phone, namely HTC One X

 

[ender323]

I'd go for a FiiO E11. You can't use a line out from the HTX OneX, so you will experience a slight increase in white noise, but not a big deal when working with cheaper amps.