Preamp no longer makes a difference after caps and wire

I just wanted to check if anyone else had this experience. My tube preamp use to be pretty important at removing the harshness from my dac. Since I’ve upgraded the wired in my whole system and caps on my speaker they gave the system a tube like quality. I’ve been skipping the tube in the preamp and the difference in sound is almost minimal. I think I would have a hard time a/b the difference.