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. 
@thewatcher101 - The  Pathos Aurium is a headphone amp. I'm not familiar with it, but I looked it up. The only "outputs" it has are for headphones, plus an 1 XLR and 1 RCA "Tape" output. In this unit, I'm not sure what the difference might be for a "tape" output vs a traditional pre-amp output. I'm not sure you are using it as intended and I'm not sure any advice you may get will be valid considering it is not a traditional pre-amp.

Just curious, how do you have this connected to the amp that powers your speakers? What amp are you using?
I guess this brings up the old issue of active pre or passive pre...or no pre! Everyone has a different opinion of course, and many listeners seem to think that the more that you can eliminate form the signal path the better. I have tried nothing as well as passive twice, and for me, I will always use an active pre. Something is just lost without it...body and three dimensionality.
After bypassing the ignition system in the Morris Minor the engine became dead quiet. No grain, no jitter, no dither, no digital glare.
Update, after a few more session of listening with it on and off, the conclusion is still to keep it. When the volume is turned to listening levels. The tubes even though impact no significant sonic signature that I can pin point, but the higher sense of realism it imparts. Usually with gear, you can tell  what it is doing, but with this preamp and the tubes I am using, the changes are so subtle but significant. By trying to identify what it was doing, I kinda of lost the point to just feeling how my system was delivering music. Very interesting
@thewatcher101 - What Amp are you using to power your speakers?