Lamm M2.2 instead Krell EVO 302

Based on my own experience, if something is wrong in that particular setup, it's a cabling.
Sumic cables are in my (and a lot other)experience incosistent product; neither sample 8among the same model) does not sound same as other. It is somewhat a fortune what you are getting when paying - you may won, but you may be deply disspointed.
So, you should try something more consistent, like Nordost, Transparent and the similar.
I would not change anything before trying new wiring.
My 5c

I sold my B&Ws for the same reason. You need to play loud to open up the speakers. I switched to Wilsons. The B&Ws play very well but only at loud volumes. I owned 801s w. FPB 600 and then tried w. VTL 750s. Always enough power but poor sound at low volumes.

Agree with Branimir.

Lamm would not offer authority, dynamic headroom and soundstage to 802Ds like the Krell can provide.

In my opinion try a pure carbon Interconnect like Stealth Nanofiber from your pre-to amp and see what happens!

--
Branimir are we gonna meet in the Munich show?

My good friend own setup similar to yours: B&W 802D, Krell EVO402, ARC REF3 and Ayre C-5xe. All Audioquest cables. He replaced ML335 with Krell EVO402 and results were much better. I agree fully with David crossover on 802D seems to really sucks the power up...
About Lamm M2.2-nice sounding amp but, also less powerfull then your EVO302. If you feel that EVO302 is not up to the task you will need to DOUBLE the power.

Just one thing-you said the you feel that there is not enough power at low level listening(if I am not wrong?)? That is more specific speaker problem(not enough low level dynamics and reslolution) then amp problem IMHO.

I had the 803D, and I also trialed the 802D at home for a while. At the time I had the Krell 400xi, but I got the Evo600 monoblocks soon after.
The B&W needs lots of power, ie. volume, to sound any good. I think the crossover sucks the power up! They really need a lot of power to overcome that damn crossover!
Your Evo302 will be up to the job no worries I think, as even with the Evo600 mononblocks I found the same as you are desribing, and they definately were not running out of power!
I will be very surprised if changing amps solves your problems...you may have to bite-the-bullet and change your speakers...as I had to.
Good luck!
David.