For B7 tube rolling ( and 2 box L7 too) please direct your HK plas to this thread: http://www.audiocircle.com/index.php?topic=127660.0
The DHT Dac idea came from HK demand, as far as I know. They also had more L7s intially than the rest of the world. The Big7 has caught on big time in the US and I think the UK as well. DSD playback is so great that its seems to be ear catcher, according to the UK folks.
CH people are ex-Anagram technology pedigree, so they have it going on for digital and may even consider LPF DSD module for the future (wink, wink)!
interesting...I read something about the Allnic 5000 DAC which people say is excellent, particularly for the money. It is Direct Heated Triode as well, no?