[PHC1]

A preamp can not improve sound beyond what is coming into it. What a great preamplifier does is preserves the signal in its fragile low level state and passes it on to an amplifier with minimal corruption. I still feel a reference level solid state preamp will excel at this task.

Back in day I owned an Ayre KX-R and that was truly a great example. The way the KX-R spot lit the soundstage and made all the instruments take their proper space on the soundstage, left to right, front to back in a virtually holographic way and brought forth clarity, dimensionality and tonal accuracy was mesmerizing. It did not achieve this with gimmickry or electronic trickery but preserved every tiny electron in the signal and guided it safely through to the amp.

I strongly believe tubes will have a different effect on that low level signal but if the design is great, it adds euphony, color, harmonic bloom and body to the sound without making mush and marshmallows out of it but we often perceive this as a positive and I’ll be the first to agree it can be very enjoyable.

Perhaps passive preamps just are not able to support the low level signal without active circuitry and the result is not quite as good, to my ears at least.

I ultimately sold the KX-R and kept my Lamm LL2.1 preamp because of the delicious tone and harmonic richness, liquid and seductive midrange but knowing damn well it was not even close to the accuracy of the KX-R which was OK for me.
We all have our taste and preference.

Taking a close look at what build quality, component selection and design that actually goes into a reference grade preamplifier like the KX-R and some others and what effort must be made to achieve a performance of that level, it becomes clear that we may not ever be able to measure and document such phenomenon in audio but our ears can certainly appreciate the effort even if our wallets can not...

I think like many things in audio, it is what it just is.