Thanks, Nsgarch, I agree with your general view, it is more like, how many systems to care for, and in my case, some portability would mean more use.
But OK, I am considering a Darkvoice 336SE, which the seller suggested instead of the Little Dot mk3 that I inquired about (although it weighs the double of the LD3).
If I should be warned before setting out on the single ended tube road (or go to some other product type, like OTL), please tell me. Since the amp will mostly be used away from my analog rig, my source will be digital files (ripped from analog LPs). These are a bit hard even in the much-improved DSD format - Polices Humanize yourself comes to mind.
So, to get the best tube sound, I am willing to forsake a few other things, but please not too much. And that is where it costs, I guess - my limit is around usd 500. Advice welcome!
Thanks Stanwal, for the Creek suggestion, and to Hens for Audio-Gd C-2C, which gets much attention at Headfi. These look like good semiportable designs and I might end up there. I agree Headfi is a good forum, but find it hard to search and get an overview of what goes on there.