Amp's suggestions for B&W Nautilus Prestige?

Jeff Rowland Design Group MC606 easily covers six channels for $12,800.

http://www.jeffrowland.com/MC606.htm

I would stay with Rowland for all 8 channels, finishing off with a couple of 501 mono-blocks, although you might go with lower watts for the tweeters, like the 201s or even the stereo 102, depending on the power need there. Finding another amp that'll match the Rowland's very low noise floor will be very tough.

I couldn't find a review of Phonosophie equipment, but looking at the chassis it's not in the same league with ARC, Rowland, or even Krell. I'd have to hear a very convincing demonstration to seriously consider it. I know there's more to an amp than the chassis, but it is a big part of controlling EFI and RFI.

Look at Guidocorona's review of the Rowland Capri pre-amp, where he compares it to his ARC Ref3. You might want to consider trading out since you seem to be putting together a no-holds-barred system.

I'm hoping your crossover is balanced. Given all those ICs, it'll be good if you can take advantage of a balanced amp topography.

Dave

Goodness Sphere, you must get around. Where did you have the pleasure of hearing the Rowland MC606 as a tri-amp solution or as part of a quad-amp? What were its shortcomings vs the Phonosophie equivalent?

Rowland has (or had two weeks ago) the 606 set up in a tri-amp configuration driving a couple of custom Magicos (not anything you've seen in the audiophile mags).

Dave