@goodnightpaul I'm Glad you made two things known.
One being, "I built and own a Dynaco ST-70, Dynaco ST-35 and an Elekit TU-8600S".
Two being, "while maintaining clarity, detail and the experience of being inside the music space".
I can't recommend enough, the Nelson Pass Korg Nutube B1 Pre-Amp'.
It has been in use within my local HiFi Group for many years now.
For the money to build the working model, there is not much out there that can offer a lucidity and insight into a recording.
If the design is built modular in a nice aesthetic casing, the basic cost will creep upwards.
Within the local HiFi Group, it has been selected over other Pre-Amps numerous times more expensive to purchase, when entered into comparison demonstrations.
One Group Member took one over a very expensive EAR Pre-Amp.
It does carry a little extra injection of gain as a basic model, but this is easily resolved if wanted to have more control.
Well worth an investigation and there is endless build support available through the forum whare it was conceived as a design.