Biamping B&W 802 with Musical Fidelity and Bryston

Alexv- Unless your amps have identical gain and sensitivity, your frequency response is going to be skewed. Anyone that understands freq. response will understand that it will be skewed in favor of the section receiving the higher gain. IE: If your mid/high section's amp has higher gain/greater sensitivity than your low's- You'll end up with a "too bright" or "thin" sounding response. It takes very few DB to sound wrong, especially when the disparity leaves a notch at the cross-over point. Find out the power output of the tubed amp you intend to use, and it's sensitivity(IE: 100W output @ 1.75V input) and find a SS amp to match, one with adjustable gain(a lot of studio/pro amps have that feature), or obtain a passive level control to attenuate it (http://www.creekaudio.co.uk/products/product_downloads/instructions/obh22.pdf).

Here's a pro amp that some of the contributors in here are in love with: (http://www.samedaymusic.com/product--BEHA500) It sports level meters, gain controls and 250WPC. That should give you the flexiblity to match the highest powered tube amp you can afford, and at it's price- you'd be able to afford much more. Below the midrange crossover point of the 802, any loss of transparency from using a pro amp should be irrelevant

Roadman99999, I've got Creek OBH-12 so the difference in amps gain is not a problem. I had in mind Bryston 4B pro or Adcom. I can’t decide on tube amp. I’m trying to minimize harshness of metal tweeters and I think I’d be better off either with pp triode or SE Class A amp.

The Bryston would be light years ahead of the Adcom, even though you're only talking about the lows. Are you certain the Toshiba is not the source of the harshness? Do you have an analog source available(TT or tuner) for comparison? Any triode based amp will give you a slightly relaxed top, but- a single-ended amp might not have the power to satisfy your SPL requirements with the 802's(even bi-amping). I don't know how loud you like your music(of course), so that's just speculation. I'm using a pair of modded Cary SLM-100's(98wpc into 6 ohms) to drive my Maggies(86db/1w/1m) and getting about 105db on peaks(without distress), crossed at 250hz(10th order) to my woofers(255wpc). You'll be crossed at a higher point(about 1 to 1.5 oct), but- I'd still wonder about your SPLs with an SET amp(your slope will be nowhere near as steep as mine). How many watts are you thinking about for your top? What kind of listening levels do you like?

I don't have analog source but I don't think it's Toshiba. Tweeters don’t sound too bad with well recorded music. Only bad recordings sound really harsh. Unfortunately a very significant part of my CD collection makes my eyes bleeding.
I can’t listen to music as loud as I wish thanks to the neighbors (I live in townhouse). I tried to bi amp my speakers with 30WPC Pass Aleph3 and 120 wpc MF and I could make my speakers sound loud enough. I think that I need at least 20WPC of tube power but I’m not sure.