I say replace your solid state preamp with a tubed one. You already have an excellent phono stage, I suggest holding on to it. Find a used quality tubed preamp from Conrad-Johnson, Audible Illusions or even Audio Research. Don't get me wrong, the Threshold is a fine unit, but if you're looking for a little extra warmth, tubes are the only way to go! Or..., since you already have a tubed phono stage, try running it straight to your amp with passive preamplification - that is just volume control, no active line stage. Try one of the the passive attenuators from DACT, EVS, Placette Audio or Audio Synthesis. With this configuration, I believe you'll get the added warmth you're looking for plus much improved transparency. I just wish I had 4K to spend on a preamp!!!
Good luck and happy listening!
Jojo
Good luck and happy listening!
Jojo