Don,
I believe Jeff’s description relates essentially to tonality and timber and detail.
I’ve been sort of obsessed with live versus reproduce sound for as long as I can remember. I used to do live versus reproduced tests of recordings through different speakers in my own home, and I’m constantly closing my eyes when the presence of un amplified sources, and taking in what to me are the salient characteristics.
Certainly there are the type of life like dynamics tend to distinguished live, even just somebody fingerpicking a guitar.
But in tonal and timbral terms, it is always struck me how relaxed and unforced and unmechanical and organic the detail is in voices and instruments. And the other thing always strikes me is how much richer, in terms of the sense of body and fulness, and the thicker richer level of harmonics. Even a single pluck string of an acoustic guitar or a single high note on a violin sounds thicker and harmonically richer and in that way warmer than what I hear through most reproduced sound.
So my may take away it’s just like Jeff’s: Real voices and instruments have an effortless clarity and presence, no technology between you and them, while the detail doesn’t seem heightened or mechanical or artificially boosted, but just “ there” and relaxed, along with the greater richness and warmth of harmonics.
So often in high-end reproduced sound, when we are struck with the effortless clarity of a system it can come from systems that are exaggerating detail, or that are tonally or harmonically lean.
Jeff’s trying to capture that combination of effortless clarity it doesn’t come with the expense of aggressive or lean/cool, but which combines both.
That’s what I feel. I’m getting in my system. So that’s helped along even further by using CJ tube amplifiers.