ARCAM compared to Krell

I don't think I would assume your Arcam gear won't drive the B&W's just fine. I know B&W's by reputation do their best with gobs and gobs of power driving them, but you may be very happy with the sound out of them with your Arcam.

When I first got back into the hobby I had an Arcam A-65 (40 watts). One dealer told me he would normally never recommend trying to drive B&W's with something that had only 40 watts, but because of the quality and stability of Arcam's poweramp output, he thought I shouldn't hesitate to give it a try. The problem is that you need an amp that can keep pace the B&W low ohm dip (around 2 ohms I believe) which can really tax lesser amps. I suspect your Arcam is up to this. I am not saying that more high quality power wouldn't be ideal, it just may not be necessary.

Krell is MUCH more expensive gear than Arcam generally, though there is some overlap between Arcam's high end and Krell's entry level stuff. Arcam gives great sonic/video value for dollar. Only you - through personal auditions - can decide if Krell offers you enough more to justify the price. Don't let any salesperson psych you out by bad mouthing your Arcam stuff as "mid-fi" or any such nonsense. For most people in most circumstances, it is great equipment.

Okay, I'm convinced - you need probably could use the heavy iron. Krell is not the only option in high-powered, quality amps, though I'm sure it is a good one.

I am not the best source for information on heavy, high-powered amps, but based on my experience you might want to look into Sim Audio for more warmth. McCormack isn't bad either. But there are many others here who know much more on this subject.

For myself, I simply cannot abide the huge torroidal power supplies, the heavy aluminum casing and completely unaesthetic, wife-unfriendly footprint of most Krell amps. They just don’t cut it in the average living room, for instance. But also, and more to the point, I personally don't think those I have heard sound as good as my Linn amps, which use a switch mode power supply (thus are in comparision light and small), are stable into any speaker load, and are pleasing to any eye. Unless you are going for the Klimax solos (10K each), Linn amps are lower powered than the big Krells. Mid level Linn amps like the 2250 or the 5125 (multi channel) are around 230 watts into 4 ohms. Still, if you have a Linn dealer where you live, they most certainly should be auditioned. They are also a great value used, if you would consider buying that way.