I believe the 'sound' you hear is really the speaker and not the amp, unless you are listening to a truly bad amp
Each equipment in the chain is capable of colouring the sound, DACs have their own signatures be it a standalone or one in say a CD player.
Similarly preamp, amp, cables and speakers too can make a difference and ofcourse the listening environment also plays a big role.
The most important of the lot is the quality of music being played.
I am of the school of thought of never equing.
I like a balanced sound with decent amount of body in the midrange, so try to achieve this through the chain.
Music is psychoacoustic, but with time and a passion for critical listening, it is possible to overcome that, and yes equipments can be a big damn difference.
Some simple filters for ears are:
Bass: should be taut and not boomy or muddy
Midrange: the most critical area (can be warm, maybe a tad bright too but not muddy or hollow)
Highs: Can be detailed or a bit rolled off to taste but not screechy, sibilant or fatiguing.