Dan D’Agostino and ARC Ref. 10

In solid state Bryston 28B monoblocks or McIntosh 601 or 1201 monoblocks are the best I've heard.  Never been a big fan of Krell / Dan's work. 
But if your already on-tubes, I go with either Audio Research Ref 250SE's or if you well off enough a pair of VAC 200iQ's or ultimately VAC Statement 450iQ monoblocks  
As with any upgrade thou, your mileage (improvement) will vary....

Should be no impedance match problems.
As the AGO is 100kohm input and the AR is is quite low (for a tube) output impedance

Cheers George 

I had a Dag Momentum with ARC Ref 40 in house to experiment with my Wilson Sashas. Absolutely wonderful in all respects. This combo is the perfect marriage of tube and ss for those who do not belong in either camp. I am sure they would work just as well for Evolution Acoustics MM3s which are fabulous speakers. 

Do you people think it will be a REAL step-up over my Rogue’s or shall I stay with tubes?

I am not a dealer for either, and quite frankly I would say yes. 

Rogue builds a great amplifier for the money but they have never been the tops in terms of speed or resoloution the amps bass is a bit tubby as well. 

Todays best solid state designs are much warmer and more involving than many of the older solid state designs. 

The only thing you may have to be leary of is that the ARC preamps are pretty neutral for a tube design with the Rogues leaning on the way warm side, so these two pieces balance nicely. 

The Krell has a hint of warmth, greater bass control, and far better dynamics. I would recommend you try the combo before you are fully commited as you may have to rebalance the system somewhat with a more netural amplifier.

Dave owner
Audio Doctor NJ

Grgr4blu, we have a customer with the Evolutions, they are nothing like the Sasahs, The Evolutions use an Aurum Cantus ribbon which is a much hotter tweeter than the soft dome of the Sashas.

So again you need to be careful as what you gain in dynamics, punch, clarity, speed and articulation you may find the slightly warm but more tonally neutral sound of the D'ag amps too much of a good thing.

It will come down to room acoustics, cabling, and digital front ends to see if the newer amp will work in those improvements while negating the more neutral voicing of that amp.

Dave owner
Audio Doctor NJ

THe other option I was considering is  a pair of VTL Siegfried 2 or MB-450s... maybe a pair of ARC 250SE...

leog2015
  Do you people think it will be a REAL step-up over my Rogue’s or shall I stay with tubes?

With the Ago having 100kohm input impedance, it's a perfect match for a passive. You could try this $49 one and send it back if you don't like it.
http://www.schiit.com/products/sys

Or the more fancy Shiit Freya, which gives you the choice of passive, tube or solid state outputs, and it remote as well as balanced or SE also returnable.
http://www.schiit.com/products/freya

Cheers George  

Audiotroy:
First, I have Sasha 1s with a titanium tweeter which is more incisive but not as refined as the new silk dome in the Sasha 2. The ARC/Dag combo was not too hot for the tweeter. Second, I never said that the Sashas were "like" the Evolutions as they are not. I did say that I thought it would be a great combo.
Leog2015:
I have a friend with your Evolutions with an all ss setup and I have heard them at length. I also have a friend with Aurum Cantus speakers with their ribbon tweeter. He happens to have a VAC front end and a somewhat warm but very natural sounding ss amp (Wells) which has a presentation quite similar to the Dags. The ribbon tweeter sounds sublime there. I believe you will hear an inviting, much more dynamic, bolder and more transparent sounding presentation if you take the ARC/Dag route. It goes without saying that you will lose some tube warmth absent the Rogues but a scrim over the sound will also be lifted. Of course, Audiotroy states the obvious--your turntable, digital front, cabling, room, etc will also play a role in the sound.

What about the Mcintosh MC-2301s for my system?

ARC Ref 40 and VTL MB450III is a great combo for me. Use the balanced connection and then tune to your speakers with the adjustable damping factor. The VTLs also benefit greatly from Herbies dampers and the type of stand and footers you use

Great combination.

http://www.audioshark.org/dagostino-audio-47/trying-out-dagostino-s250-13037.html