It is great when you plunk down a new piece of equipment and the difference is instantly obvious and huge. That happens when one is working up to the higher echelons of equipment. But once you are there things can be different.
First, as pointed out by @audphile1, it is way too soon to make a judgement.
It is too soon even if the amp was broken in. I would make sure to get at least 20 hours or hopefully more on it in your system. (If it is new… then you really will needs hundreds). Second, you want to spend at least a couple weeks before swapping back… listening to the music not trying to listen to the amp. The music you listen to over time will reveal differences. The analytical thinking is only good for glaring differences in some very obvious parameters unless you are really experienced in doing it (like you are a dealer who swaps stuff for a living).
You are likely to hear the differences when you swap back to your old amp after a good long exposure to listening to music.
Having said all that. Yes, there is such a thing as synergy. It was not by accident I finally converged on my all Audio Research system (under my ID). In this case, dropping the DAC and amp in were earth shatteringly obvious. But I have compared very high end DACs and while the differences seemed miniscule and required lots of exposure to reveal, once revealed there was no question they had a very profound effect on my system.