An Amplifier Change for my Wilson Sophia 2's?

Once Bob Carver created best amp: Sunfire Sig 600. It’s load invariant and can be used as welding machine as well(hey if needed).

It drives ANY speaker of ANY size super clean.

How about 1.2kW into 4 Ohms would sound like? I heard these speakers with Electrocompaniet AW 250/TaCT RCS2 preamp and the sound was ’hiding’ inside the box with no imaging whatsoever.

After they’ve been connected to this relatively light powerhouse mentioned above (hey, substantially lighter than Electrocompaniet), They started to open and showing soundstaging capabilities.

Using VT100 on Wilson Sophia speaker is similar to using Honda 1.5L engine on FreightLiner trucks. This is having in mind that you have ARC line stage with pretty high gain on the first place. 

Well, Al,
If you and few other poster were speaking about where 100W per channel can bring Wilson Sophia, it’s not truly the case and I’ll explain why.
That ARC VT100 would be able to supply to my guesstimate only a third or a quarter of specified power which is only 25...30W realistically at highest volume setting. Although tube amps soft-clip, there’s still not enough CURRENT to move drivers and therefore actual power halves or even quarters. ARC line preamps in general have 20dB of gain so combined 80dB of gain is substantially enough -- no need to move gain higher to 73dB.
Mentioned earlier Bryston 3B-st or 3b-sst/sst2 amps can do much better job but still not enough.
As I’ve mentioned before 250W Electrocompaniet amp wasn’t enough either. It was loud enough, but no 3d and imaging.
400+Wpc/8Ohm and 600+WPC/4Ohm is about right ’prescription’ otherwise money wasted.
There’s one Sunfire Sig 600 for sale here on audiogon and I wish to stretch my budget and get it. I was foolish not to get it at more than half of price years ago, but trust me It’s the best amp ever made for any budget.

Increasing from 100 watts to 400 watts would give another 6 db of volume. Doubling the watts equals a 3 db volume increase. A volume increase of 10 db would sound twice as loud twice as loud.

In other words the starting point isn't 100 watts. Try going from 30watts: 60, 120, 240, 480 ... 12dB -- Now these figures bring you much closer to reality.

I've known lots about price categories, but quit worrying about that long time ago.
Sunfire sig 600 was the amp able to make WS speakers literally disappear and bring REAL stage.
If you compare depreciation of 7bst vs. sig 600(both were actually manufactured at nearly same time), 7bst lost near 70% of value getting close to the end of bullet-proof Bryston warranty and sig 600 haven't lost a penny and sold often for higher dollar now than it was new.
That should tell quite something I dare to believe. 
There's no doubt to the quality of that amp despite being one of the first class D amps in high-end audio and if I had $30k+ speakers, I would be more than confident hooking them up to this unit.

Al,

The signal response measurements are done at 1kHz. Therefore for some particular reason called 'X', OP asks the question 'Y' for some same reason everything is perhaps 10...12db hungry of SPL and there's one analogy answer that speaks for itself:

If you have glass of water and you try to fill-up the jar, you will need much more than one glass of water.