Are you asking if the SR60s sound better with an amp than without an amp?
The "right" amps amplify without distortion, provided that they are not fed a distorted signal; some amps filter distorted signals because you will have to turn down the volume, and in doing so the distortion is lessened; the bass will sound non distorted for the same reasons.
my amp does make the music better, that's the whole reason I bought it. If I listen to a CD using my marantz,( good source), and going through my NAD amp it doesn't sound as musical and uplifting as through the marantz and into my chiara. From what I've learned here and since experienced, the complete chain is key to making music sound good.
A good amp provides headphones with enough electrical current and voltage at all times, so that they accurately reproduce the input signal, with as little change in the sound as possible (i.e. just a wire with gain).
Amps provide enough current and voltage swing do let headphones accurately do their job. Without a decent headphone amplifier, a lot of headphones sound muddy, boring, uninvolving, bass-shy etc.
However, it all depends on the headphone. With HP-1000s for example, the difference is like night and day.