Bi-Amping B&W 802N - Who's doing it and with what?

I have B&W 802N and a Krell FPB 200c. I'm considering using the 200c on the low end and biamping with McIntosh or tubes for the mid / upper. What's the prognosis - is this a good idea? If anyone is doing this, what's your set up? Recommendations?

Wadia 850
Krell FPB 200c
B&W Nautilus 802
Cardas Golden Cross speaker cable / interconnects
What performance inprovements are you looking to accomplish?

Most likely the addition of a second amplifier will also require an outboard crossover device (and another interconnect)so that gains can be properly matched. Even if the Wadia can drive single ended output along with the balanced output you have connected to the Krell, I think it would be hard to find a single ended input amp with high enough gain to matched the balanced gain.

For fewer dollars, you may notice an improvement by adding a preamplifier instead. Several magazine reviewers have recommended the use of a preamp to get the last bit of performance out of the Wadia.
I agree with Alexanderj's suggestion. Your FPB200C would give you a better performance all the way around if you will add an active preamp, perhaps a tube for that added "life like" sound... I think direct connection would give you the cleanest sound but I prefer full bodied sound from my tube preamp driving FPB and N-802s.
I'm using 4 Monarchy Audio SE-100 Delux' to drive my N802's. I would have preferred to go balanced, but my processor won't allow that. Single ended is just fine however, and I don't have to worry about gain variations with this configuration. At any rate, N802's love to be bi-amped. If I was using these in my music room, I would have bi-amped them with Electrocompaniet amplification, which is what I use in my music room.
I am bi-amping my N802's in an unusual way and it works very well. I have inquired about this setup with several knowledgeable sources, including an email correspondence with B&W, who assured me that it was OK.

The left and right speaker main outputs from my Denon AVR-5800 receiver (each rated at 170 watts/8 ohms) are run to the high frequency/mid-range binding posts on the N802's.

Then a pair of Audioquest Viper interconnects from the left and right pre-outs on the back of the Denon receiver to a Denon POA-5200 stereo amplifier (each channel 120watts/8 ohms). Left and right speaker main outputs from the POA-5200 are run to the bass binding posts on the 802's. It would seem that they should be wired the other way around, with the higher power from the receiver going to the bass portion of the 802's, but I tried it that way and it sounds much better with the higher power going to the tweeter/mid-range.

I know this is a bit unconventional but the results are spectacular. The tech rep from B&W confirmed that the Nautilus series is designed to be bi-amped and they definitely sound much cleaner and dynamic than when they were bi-wired.

The N802's demand and deserve as much clean juice as you can give them to really open up and work their magic. In fact I intend to eventually replace the Denon POA-5200 amp with a more powerful amp such as a 250W Krell. It then becomes a question of what is a safe amount of power to be delivered to each portion of the 802's without the risk of frying the mid's or tweeter. I will consult with B&W on that one.

Some of you audiophile purists may scoff at using a Denon receiver and thinking of it as a source for audiophile quality sound. You might be surprised at what Denon put into that receiver to ensure an audiophile quality sound for music playback. Yes, it is basically a home theater receiver but there is internal switching to shut off all other internal circuits and run only four high-powered DAC's per stereo channel. I'll put it up against any of your separates anyday. This has been confirmed by several well respected reviewers.

Anyway, I hope this is a helpful suggestion as a possibility.

BTW, I love these these 802's. I previously owned N804's and thought they were good, which they are, but the dynamics and the strength of these 802's are incredible. The 804's are now in the rear as excellent surrounds, especially for multichannel music.