The best result we hope, enjoy your music now.
Also thanks for everyone who share their experience with others and help the others.
Well in that case, not really. If you just enjoy the natural sound signature of your headphones, then I don't think there's any need.
Many here will say that there are definite improvements, but how much of it is real and how much of a difference there is in reality are two separate things. An amp is mostly adding gain to the signal, its the same as before, just amplified. If you're looking to enhance bass/treble/mids then you can use the EQ, or maybe a third party app to do that.
Can we be clear that this is simply not true? If it were there would be no difference between a clock radio playing at adequate volume and a high-end stereo playing at the same volume. The quality of the signal the amp gets and the quality of the amp itself can vary tremendously. Volume is only a small component of the totality. In practice, yes, moving from the signal a DAP gives your transducers from of its own HP out to the signal that comes from line-out and an external amp can make a very significant difference.
An amplifier can improve sound quality, however that does not mean you will be able to perceive that improvement. Some sources don't need to be amplified. IMHO, and after all the money I threw away in this "hobby" I would not buy an amplifier if I were to choose again, unless the only source you have is a bad portable MP3 player.
To know more about it you should know the source's output FR range (measured by RMAA or similar) and the difference caused by an impedance load.