SF Extremas

I owned the Extremas and really loved them for their rich, refined midrange, great dynamics and silky smooth and detailed top end. Very musical and involving speakers. The ARC 100 mkiii will drive them OK, but if you listen at higher levels (and that's what Extremas really like), you may find the dynamics somewhat compressed. To really open up they would need 150 - 200 good tube watts or even more if driven by solid state.

The Extrema is one of the best monitors ever made,
the drawback is that they require a lot of power.
I first used them with an Audio research vt200 and they sounded good,what a difference when i changed amplifiers
The Plinius SA250MKIV made them sing and had dynamics to die for.

I used to own Extrema and Merlin VSM. No contest, Extrema is in a different league and VSM is not even close even with BAM, and I am not just talking about bass. Extrema was much more musical and less fatiguing even though they use the same tweeter (according to Dynaudio, there are 12 versions of Esotar 330).

No, VT-100 is not enough, nor will VT-200 be enough. In fact, I doubt any tube amp can do justice of the speakers. I powered them with SF Power 3 for most of the music, but had to run solid state (Pass or Rowland) on some. My recommendation is a good solid state, Pass or Plinius should do well depending on your taste.

Semi is correct. There is no way in history a 100 watt tube amp will be able to power the Extremas.
The Extremas need so much power. The only tube amps that can power them are the big Conrad Johnsons, Jadis or the Audio Valve tube amps.
You need amps like the Rowland 7 mono blocks.
When the Extremas have the power, they sound incredible. The best midrange I ever heard in my life.
That Skaaning midbase is unreal.