You definitely need an amp, even if it's built into your playing device. The thing is there are junk amps and good amps. If your device has a poor amp, chaining another amp to it will not do any good. You would need to take the line out of your player and route that to a good amp and then your cans. If your player does not have a line out and its amp sucks, get a proper player. I left DACs out of this discussion for now.
Once you get to good amps, there is little difference in what can be truly perceived, even if you spend thousands of dollars. Yes some of you will get upset at what I just said, but you would need to learn about expectation bias, suggestion and the way we color our perception as well as the way auditory memory works. There are excellent studies on this topic.
So I would avoid the bad amps. Ones that are designed and built well are what you would be looking for. Don't expect much for $50 and you don't need to spend a grand or more either.
Be wary of some of the chit chat on the forums, you will find all sort of impossible claims and observations. Someone posted the below video in another thread, it is worth watching and will open your eyes to how brains work. Try the below link, it's worth it.