If I upgrade my speaker, do I need to ...

I currently have Audible Illusions L1 preamp, McCormack DNA-1 Deluxe amp, and a pair of B&W CDM-9NT. I have been thinking to upgrade the speaker to B&W Nautilus 802. If I do that, do I need to upgrade my amp, or add another one to bi-amp in order to get the most out of the 802? I am just trying to do some budgeting.

I think you should live with yr amp as is for a while, then try out biamping using a cheap SS on the woofers. There's a Quad selling here for $600 for example.

Your amp is a good performer for its price and "upgrading" it to better drive those speakers will cost a lot of money: a big Krell for example, or a big Symphonic Line or Mac or a Mark Lev...
802N or 802D? that might matter here.

Despite the 92db eff rating on the BW N type speaker, they do enjoy more power more so. Your amp, I believe ought to run them… I’ve heard of folks using a 60wpc CJ tube amp on them actually…. But to what extent the SQ was, I can’t say… but noise will come out of them, that’s for sure.

I owned the 9NTs with the hopes of moving into the 802Ns next. That never happened..I heard the 9NTs on several amps and a couple of receivers… Rotel, B&K Arcam, Sony, & Krell. The more power the amp output, the better the speakers enjoyed it. I’ve got to say here as well, most speakers respond better to more applied power…. Or more accurately, to the availability of greater cleaner power reserves.

All that said, perhaps though, How much power you can afford is likely the issue here, and not what is best for the 802s. I’d suspect 300 – 400wpc should be sufficient enough power for them in an average sized room. Until you get into the 800 series or the Nautilus series, I’d say not to worry over bi or tri amping BW speakers. Just add goodly ample capable power to ‘em like some amp with guts that never comes close to running out of steam, and have fun..

What’s best for ‘em? I’d say something from the 500 – 600wpc arena…. BAT, Classe, McIntosh, maybe even Levinson’s big boys…. But that’s just me and what they sounded like with huge amps pushing them…. And of course… IMHO. I used a KAV 250 on my 9NTs.

you might also consider another speaker line altogether that won't require an amp upgrade too. BW aren't the last word in speakers, nor are nay others .... there are plenty of 'em out there which do just as well or better AND with your current amp!
Thanks for the response. It seems I will need more power to drive the 802N, and so, I need to factor that into the budget. And since the speaker alone is a stretch for me, I will need to put aside this upgrade for sometime.

BTW, Blindjim, when you say there are other speakers choices, can you give some examples? I am open to other suggestions.