Just got some thoughts i want to share about audio sources. I have got my computer, iphone, and finally heard a couple of amps.
First off the computer is an awful source with its built in headphone amplifier/dac. Very little bass, and the bass that might exist seem to be unaccurate and underpowered (but i guess this depends on what you plug in to the computer. For instance i use only 16 ohms IEM's). The middles aren't good either, and they sound un-musical and boring, and for the treble its just a pain. Just want to mention, that my motherboard is new, and it isn't cheap (120 dollars or so). Static noice is present here.
My iPhone seems to be a more capable source, and its quite neutral. Not good, nor bad, except the bass that doesn't seem to be very controlled, and kind of dull. Also static noice is present.
Going to the amps. you get an overall more musical experience, with more fullness and accuracy to the sound, and it just seems more musical in every way. The result is, that the earphone seems to be full and not underpowered. But ofc all this does vary depending on which amp you use, of course. The static noise may also vary, but it is less in general
Just wanted to say, that this is what i think of the different sources that i have tried/use.
You can put it like this: My iphone is a considerable opgrade from my pc, and an amp is a considerable upgrade over the iphone.
Definitely worth the money to get an amp, if you have got some decent ear-/headphones and are considering to spend more money on audio in the future.