Mcintosh MC275 versus MC501 ?

one foot long, each side short as possible

one foot long, each side short as possible

Ordinarily, a short(er) cable (anything under 5 feet is sufficient) will help preserve the limited damping capability of a tube amp. However with (especially) a braided cable, like the Kimber, a very short length may work against you because of the low frequency oscillations (some people call them 'reflections') that can form in a cable that has high inductance and capacitance like the braided Kimber. (This is common in undersized power cords also.) I would suggest you try a cable of 4-5 feet in length and preferably solid core (or very few strands.) If you want to do an inexpensive experiment, go to Home Depot or Ace etc., and get four 5 foot lengths of insulated copper house wiring, 10 AWG, and see if that doesn't improve your bass performance.

The (current model) MC275 develops 90w/ch and should have no trouble driving an 802 with its 90dB sensitivity (unless you have a large room and/or listen loud -- in which case you might want two MC275's in mono ;--) But it's important to note, that B&W specifies using very low resistance speaker cable with their speakers (probably for compatibility with their crossover insertion impedance), and that requirement translates into "fat copper conductor" which does not describe a braided cable (nothing against Kimber) but I know many people who love the sound of tubes with their B&W's, and they all use cables with lots of metal and very low resistance/foot specifications. Try it, it'll cost you maybe $10 ;--)

thanks Nsgarch

can you recommend a make of such a cable that has those charactistics? ideally, I would like to have 2 five footers.

Why don't you just try some solid copper from HD as I suggested. I'm not recommending it as a permanent solution; but it will tell you right away if that (speaker cables) is the problem. Another thing you want to double check is your amplifier taps -- I'm assuming you're aware that when you bridge the 275's into mono, the impedance designation printed on the amp for each speaker tap is no longer valid and you have to go up a tap (i.e., an 8 ohm speaker should be hooked up to the 16 ohm tap.) Check the owners manual.

As for cables other than the Kimber, there's a pair of one of the all-time great workhorse speaker cables (Straightwire Maestro) available used (always buy speaker cable used ;--) on the Gon right now, for no money, in just the length you need: http://www.audiogon.com/cgi-bin/cls.pl?cablspkr&1273259411&/Straight-Wire-Maestro-SpeakerThere are also a couple pairs of Virtuosos, a later design, for a little more money:
http://www.audiogon.com/cgi-bin/cls.pl?cablspkr&1274549629&/Straightwire-Virtuoso-Speaker-
I used both models for years (the Maestros for 10 years) and they are one of those sleeper products that are very hard to beat (especially for the used price!)

If you want to spend some bucks, a pair of mid-priced Virtual Dynamics. Most VD speaker cables come as two separate cables per speaker (a plus run and a minus run) with solid conductors. This completely eliminates capacitance and inductance. If you want to spend a lot of bucks, Purist Venustas or Provectus (the Provectus is solid core two runs like the VD) but you're probably talking $1200+, even used.

thanks for the recommendations, Nsgarch. I'll be experimenting.
Ted.