my friend uses a pass aleph 1.2 monoblocks (200w/8 ohms) to drive his extremas, and they sound fine. 100-200w of QUALITY amplification should get the ball rolling. i wish SF would consider making them again, perhaps with an improved stand.
stereophile's review stated they sounded good right out of the box!! if that isn't amazing i don't know what is. the amatis got a good review, only m.fremer sold his pair before anyone could say wattpuppy7. the strads look nice but didn't do anything new for $40k. the new amati anniversarios haven't created much of a stir thus far. but the electra amators and the extremas were compact and sounded like full sized full ranged state of the art imaging etc. the drivers can probably still be replaced (dynaudio), and the woodwork for those of us who admire it will endure for many years with a little polish. i own guarneri homages, and they give chamber music appropriate character without having to apply any further audio terminologies. are the latest versions better? probably. but whether or not they convey music with more emotion is a big "maybe".
ANYWAY, MY big speech is prompted by the 1st time i heard extremas, which was at the stereophile show in miami and i stayed for a very long time in that room where, for me, i heard the best music making in the building (only the MBL-101's impressed me as much). so naturally, with big eyes and a small wallet,
i yearned for a pair, but could not find a demo or used sample (my budget was $5k, and THAT was a big stretch).
much later, traveling down the road of absurd desire for ridiculously expensive audio stuff, i came upon eggleston andras with the same tweeter used in the extremas, and got a used pair. so what if they lacked the sonus faber "look"?
at least they sounded ALOT like the extremas, with even more bass (down to 20Hz!) but you never lose sight of a beautifully executed design like the extremas. enough already. get a pair.(!)