calling all Guru;s, Ideas on audiophyle high effeiciency speakers solicited

Not listening to the combo yet. Soon I hope but not yet. Currently not happy with my amplification into the 803s Adcom 555II that I had to pull out of retirement after my Krell KAV decided to take a permanent vacation. Thats when the tube bug bit me. Tube amps may not be powerful enough to drive the 803s into nirvana

How did you feel when the Krell worked ? I do not feel tubes are a match with your speakers.

Loved the sound with the Krell, would not mind trying a more efficient speaker with a tube sys but need to know what to look for

You're speakers allegedly have 90db sensitivity with a nominal impedance of 8 ohms. In theory, that's fairly efficient by today's standards, and should work with a tube amp of about 50 watts. After all, B&W recommends a minimum of 50 watts. However, it seems most B&W owners end up settling with powerful SS amps. 

If you want to try tubes with your B&Ws, I have no doubt that a Rogue Audio Cronus Magnum will drive them to sane volumes. That's about the most glass power one can get for the money. If your heart is set on low power SET amps, you'll need different speakers, ideally some of 94db sensitivity or greater.

 Some will tell you that tubes necessitate 3-digit sensitivity. That's complete rubbish. I can drive my 87db spec speakers to loud volumes with 45 tube watts. Also, room gain, listening distance, music genres, particular amp design, and desired headroom play a significant role.

Contrary to untutored belief tubes are NOT inherently better than transistors! I own many amps of both types! Your 803D2's are truly excellent speakers and capable of better sound than ANY high-sensitivity types. I can recommend a New York Audio Labs NYAL Moscode 300 (tube/MOSFET hybrid) to power the B&W's. A superb amp designed by George Kaye - and capable of handling difficult loads! And being a hybrid it will give you a nice taste of tube sound - without the drawbacks of an all-tube amp!