Preamp no longer makes a difference after caps and wire

The Pathos Aurium is a headphone amp, not a pre-amp. I read the user manual. According to the user manual, the "tape" outputs are a bypass. To me that implies that the tube and headphone amp are not in the circuit at all if you use the outputs.

I suspect you may not be using the Pathos properly. That would explain why you don't hear any difference when you turn off the Pathos. 

How are you "skipping" the tube in the pre-amp"? Are you turning off the Pathos?

All this tells me is that your DAC is much better than the rest of your system, and your speakers must not be very good. I've heard good balanced systems from moderate to very expensive and the preamp always makes a large difference!

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. 

I would talk with Pathos and describe your goals for the unit and how it is hooked up, I think they are in a better position to tell you how to proceed