EMM Labs Pre 2 and the latest iteration PRE, in my experience, are the best of the best. The best cost benefit ratio would belong to a used PRE 2 (available on the Internet).
High End SS Preamplifier Ayre, EMM Labs, ML, or Pass
I have Clayton M300's that I'm looking to pair with a SS preamp to drive Von Schweikert VR-5 Anni's. Looking for opinions on Ayre KX-R/Twenty, Pre2, or XP-20/30 or other as potential options (ML). Interested in members opinions on possible options. Looking for that neutral, transparent, accurate tonal harmonic musical reproduction that isn't analytical, dry, lean, or fatiguing.