What should I do - PS Audio DAC with or without Preamp

Finally, gave it a test and using the preamp with tube stage was the clear winner.

I have been through this several times testing my Wadia 321 DAC as a preamp as it is balanced as well as the power amp.  But my Mullard Rogue RP-1 only has single ended. Even with Balanced and some relatively nice XLR Audioquest cables the system always sounds a touch better (smoother) to my ears with my tubed pre in the mix.  

About once a year I switch back to the Wadia pre only to return to the Rogue.

I guess, bottomline is that a good preamp is the way to go.

👍😊 For most every system this is true. The preamp is the heart and soul of a system.

Most, but not all D2C brands will cost 50-80% less than their "traditional retail" equivalents because they do not have to have added margins for distributors and retailers. PS Audio is slightly different in that when they went D2C in the US, they did not change their pricing.