Which amplifier to drive B&W Nautilus 802?

Can you help me which amplifier match my Nautilus 802.
How many watts do I need.
Rahter than name specific amps, I'll describe the TYPE you need IMO: a good voltage provider, with good engineering for impedance tolerance from the amp. This means a very hefty power supply. So, an expensive amp:(

As to the watt rating... assuming you'll be listening at LESS than the 802s' reference efficiency (i.e.less than ~90,5db @ 2,83V on low passages), a SS rated at +100W A/AB class OR class A ~50W should do. High quality tubes should offer a nice sound. I would expect to need 75~100W.

The best is to TRY out a few models for yourself, however.

Gregm gives you good advice. I happen to agree with him as that was my personal experience as a former B&W owner.I used to own a pair of the (less exalted) DM series & even tho I had them hooked up to my (German) Symphonic Line amps, they never really sounded their best unless I cranked up the volume. They had below average low volume details despite the Symphonic Line amps being high current amps. I think that this had to do with the xover component quality & topology.
Hence, look for a high current amp - not necessarily a high wattage amp but a high current amp.
If you can lay your hands on the oldie but goldie Plinius SA-50 power amp that should give you decent SPL assuming that you will listen at the 85dB SPL level. I'm sure that it can provide more SPL but I don't have a feel for where it will commence straining itself with the N802. Often I see Plinius SA-250, SA-102, Krell FPB-XXX i.e. the highest power level you can afford!, Rowland Model 10 & Model 12, Pass X350, Spectron Musician II driving the N801, N802 & N803 speakers.
I found that the cleaner the power amplification source, the better the B&W speakers sounded i.e. their sound muddies up very quickly as the quality of amplification degrades. FWIW. IMHO. YMMV.
I think you need an amp that puts out atleast 400 watts into 4 ohm load. Solid state, no tubes unless it's a real powerful one.
I don't know about any of the technical or mathematical reasons, but I have found that the 802's are dramatically different if you give them as many watts as you possibly can. I ran them with about 170W per speaker solid state for awhile, then started bi-amping them w/170W to the bass portion of the speakers (lower terminals), and 200W to the mid/tweeter portion (upper terminals). Only bass above 80hZ is going to the 802's, anything below that goes to a Velodyne subwoofer.

The first time I fired them up after the bi-amping I almost fell on the floor. The music was so much more real that it was scary. For the first time I fully undestood the term "dynamics". Every type of music has an unbelievable presence and detail. From unacommpanied vocal and guitar to full symphony orchestras, it is now all right there in the room. In fact, just for fun, I would like to give them 300W per terminal (600W/speaker) but that is not financially possible right now.

At one point I emailed B&W and ask if it was possible to overamp the 802's, and the engineer replied that the biggest danger to damaging the 802's was in underpowering them, and that they are built to take huge amounts of power and that their 500W per speaker is a very conservative rating.

I have read similar remarks in other online reviews/chats from 802 owners, saying that to really open them up and take full advantage of their capability you need to give them as much high quality juice as possible. They will still sound really good with lower wattage, better than most speakers out there, but these things are heavy duty speakers that were made for lots of power.

You don't necessarily have to bi-amp, but the engineer also confirmed that they were designed to play more efficiently and with more purity in a bi-amp setup.

Anyway you do it, they are awesome speakers that I intend to enjoy for a long time.
I agree with Greg try many different amps, but I would definitely stick with Solid state.

1. Chord abbey Road studio uses them on their N801's
2. Krell Used KSA-250 or FPB series are plentiful
3. Mark Levinson Good deals can be had on 335 or 336.
4. Plinius 250's are out there
5. Electrocompaniet Not many of these out there but
they have an amp designed to drive B&W speakers.
I would carefully read and re-read the comments from all of the above posters. But once you get the amp you like, then concentrate on the rest of the components. Unfortunately, you cannot begin to understand what these Nautilus series speakers can do until you have top quality in the entire audio chain. I don't belive they are without flaw. But they can sound really crappy when not set up properly.

Also, if your budget is tight after the amp purchase, start to experiment with different cables to dial in the best sound for the gear you have at that time.

Let us know what amp you decided to buy.
The Musical Fidelity Tri-Vista Intergrated amp sounds fantastic with the 802s.
Bombaywalla gives some very good choices. I can simply share my experience with N803's; I had a Levinson No.383 and a BAT VK-200 powering them with ok results, at best. A switch to the Rowland Concentra II, more powerful btw, and this made a HUGE improvement in the performance. That said, I would obviously recommend JRG, but I believe the others Bombay lists also would be a good match.
I have had N802s for 4 years. I have tried several Krell amps with them. I have found, the more power to them, the better. If you can make bi-amping work, do it. If not, bi-wire them. I wish I could afford more power to them but I cannot. So, right now I run Krell fpb 300cx bi-wired.
I too own a set of N802's and would second many of the comments. I currently use a 7 channel 300wpc Sherbourn. Initially, I used 2 of the amps channels to drive the 802's; then switched to 4 channels to "biamp." Wow! what a difference in dynamics when I aded the other 2 channels with the additional power. Like yourself, I want to take the next step and upgrade the amp and have been considering a Pass X350. However, I question what is to be gained by changing to a two channel amp of higher quality. The speakers sound as if they now have the necessary power and the dynamics sound great.
In lieu of a couple responses, I agree with the more good power you can give them the better, this line likes power. Jayctoy suggested the Plinius SA100, I disagree with this. I have talked with dealers that agree the SA250 is a nice match but the SA100 isn't enough, furthermore I heard a SA100 on my N803's and it was 'ok', same as the other 100 watt amps I had on them; 100 watts just doesn't seem enough.
Thank you for the feedbacks.
Think I will go for bi-amping, and amp with 300watt in 8 ohm and 600 watt in 4 ohm.
I have the N801 and having tried the following amps: Bryston 4BST, CJ Premier 11a, Pass X250, and now Pass X350, I am convinced that high-powered solid state is the way to go. 200 watts/ch is the minimum. These speakers will handle as much power as your amp can output.

Looks like a lot of people are suggesting bi-amping them as well. I will have to go try that...some day.
Tubes give a very nice sound to B&W's. However, you cannot drive them well without high wattage amps. You can use as little as 100 w. per channel, i.e. Audio Research VT100, etc. You will, however, not obtain the ultimate in sheer muscle unless you go to more like 200 w. of tube power. The Pass X350 is certainly a good choice as well, and I have heard it on these.
Don't know if I'm to late to help. I've owned N802's for two years I Bi-amped them with two crown DC300As'150 watts per channel. They sounded nice. I then stepped up to a modified PSA which pushes 480 per side. The bigger amp really made them sing. I no longer Bi-amp but do bi-wire, (kimber bifocals)My advice is get the biggest solid state you can, they love power. I've wanted to go tubes but am afraid that I couldn't aford one with enough power to do them justice. My next step will be a pair of serious mono blocks, minimun 300 watts. happy listening
If you can demo Edge amps with the 802's do so. They are smooth and natural with no loss of detail. If you can't afford the NL series try an M8 (which I personally own) or the new G series. With how great they sound I am surprised there is not more written about them.