from my conversations with Herve Deletraz (Mr. darTZeel) my understanding is that he was working on the NHB-108 for possibly at least 10 years (maybe 15 years or since he graduated from Engineering school, can't recall exactly as this conversation was some years ago) prior to it's commercial introduction in 2002-2003. I think the number '108' refers to the number of versions it took to get to that point. not sure whether it was '8' or '108'.
it is amazing and remarkable that Herve's first commercial product, now 14-15 years young, is still a standard setting and totally current product. not many others out there like that. that is true value for customers.
if you read his owners manual for the NHB-108 there are nuggets in there regarding his view of circuit purity and the type of distortion that humans prefer and abhor. and of course, his views on interfaces between line level components.