If this were my money, given my room, my listening tastes and the rest of my system and using this combination today my gut reaction is that I would have to spend in excess of £2,000 at today’s new prices to get even a small sonic improvement (as distinct from a sonic difference) and probably £3,000-4,000 to have a noticeable, worthwhile, consistent and across-the-board improvement.

I can think of no finer testament to this classic engineering than that.
http://www.hifianswers.com/2017/08/b...howard-popeck/