Honestly, I've only had a few ales...
Hello Dominic,
A Neurochrome could be the solid state solution but here are a couple of left-field suggestions.
Perhaps too far out in the weeds, but worth a look over a drink or two.
If you want to modify rather than build from scratch, I have flashbacks to an amp called a BAT VK-60.
(BAT = Balanced Audio Technology)
It will take no nonsense from your Troels, of that I'm confident given the spec, but caveat emptor in all other respects.
Scoot over here:
https://www.stereophile.com/tubepreamps/766/index.html
Oooh! Check this out.
https://www.ebay.co.uk/itm/BAT-VK60/...IAAOSwwBZfb5L4
(Nowt to do with me.)
If the DIY spirit is strong, then you may wish to become best mates with this chap:
http://soundmovements.co.uk/diyaudio/KK_PP300B.html
Perhaps a power amp with differential operation will dance with your DCB1?