Hi John. You are lucky to get your hands on a Neoteric 60, it was a rarely seen amplifier even when it was being made back in the early seventies, probably due to costing the equivalent of two weeks wages for the average bloke. The design was extremely advanced for its time and claimed to exceed the spec of just about all others back then. The amp is a proper collectors item now and may well be worth a quid or two, it's really just too scarce to put a value on. I have the full details in my 1971 G.W.Smith catalogue and could scan it for you if you are interested.
It is impossible for anything digital to sound analogue, because it isn't analogue!