A preamp recommendation

Hello everyone,  I'm looking for a "neutral" preamp that does not emphasize and de-emphasize any frequency range but has just a tiny bit of warmth.  Accurate harmonic information resulting in natural instrumental timbre, outstanding sound staging and imaging, solid extended bass without typical under controlled bass of typical tubes or over damped bass of transistors, crystalline smooth extended high frequency, excellent micro and macro dynamics, and clear transparent sound are all important to me.  I don't like hyper detailed sound typical of some transistor preamps or overly smooth warm sound of some tube preamps.  Currently, my favorite preamp is an autoformer passive preamp which gives many of the sound quality I like, but it lacks the drive and impact I get from active preamps. I have auditioned some top preamps from Audio Research, D'Agustino, Pass, among others, but was underwhelmed due to lack of transparency, inaccurate timbre, and/or significant deviation from overall neutrality.  I don't care if the preamp is solid state or tube, long as my requirements are met.  All of my amps have input impedance of 50KOhms or above. Which preamp would best fit my taste?  Any preamp new or used $15k or under would be on my list. Thank you.