Ray over at the diyAudio forum has been working on his flip-flop/BCF project:
I’ve just finished a project to roll up the developments into a more ‘finished’ build, feeding the balanced outputs from the flip-flop board into a Broskie BCF buffer stage. I’m using Nicks MJ Statistical Regulator for the B+ and one of Andrew’s indirect filament supplies
Project info at diyAudio forum.