Preamp no longer makes a difference after caps and wire

I can turn the preamp off, and it just bypasses it. 

Even when I turn it on the difference are extremely minor to warrant keeping it in the system generating heat. 

replaced all IC, and speaker cables. 

Pathos Aurium

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

It took a lot of tube rolling to get here, I've tried some really nice 'holy grail' tubes from telefunken, siemens, mullard, and russians. 

Turns out they all had coloration, the only ones that were neutral to my ears were matsushita/national - some very inexpensive tubes. 

They are biamped - audiosource 310v for woofers and mini mite monos for hf. 

The preamp was recommended in one of the last few articles written by Arnie Nudell. 

You might be right, the dac is Mirus Pro speakers are JBL 4319 recapped with mundorf supreme. The DAC by price is twice the speakers.

But the preamp now is significant if you don't try to look for what it is doing, because after some time, the music isn't very engaging without it.