@donquichotte
sorry, i lied... :)
i never had the 40.2 anniversary model... i had the original 40’s, then 40.1. then 40.2, then 40.3xd (the anniversary series are identical to the .3xd sonically except the badging, the model designation was changed when time passed the actual anniversary year...)
the original 40’s i had were a pair of the pro version, with britex vinyl cabinet veneer and metal side handles, this generation had very hard-to-tame bass, quite boomy especially in the midbass, a somewhat wooly midrange and a laid back tweeter -- but had that big, life sized sound and a magic with certain voices and acoustic instruments (it got solo piano right!!)
40.1 revision somewhat tightened up the midbass (slightly reduced efficiency too) and midrange wooliness, this resulted, i suspect, from crossover changes and some subtle changes to the cabinet panels so they became less resonant
40.2 further deepened the deep bass and pulled back the midbass and further cleaned up the midrange wooliness, treble brought forward a noticeable step in this version from the .1 - a more balanced speaker was my takeaway
40.3xd is very very close t0 40.2... i was expecting a significant change, but could hear none... if blind a/b-ed i could not confidently pick one over the other with confidence... perhaps the treble ever so slightly livelier... but once again, if there is a difference it was so subtle i could not be sure even with very concentrated comparison - these speakers remain with a laid back treble relative to midrange and bass (thus their wonderful easeful presentation over all)
in each and every case, i felt that tube amps could not sufficiently control the woofer and bass presentation, irrespective of placement -- in my view, these big harbeths require high level high-ish power (sweet sounding non grainy) solid state amplification -- which deals with lower efficiency, controls the woofer for deeper deep bass and cleaner midbass, slightly leans out the midrange (and makes it less diffuse and larger-than-life sounding), and slightly brings forward the highs, thus enhancing imaging