Thanks, i am not talking about AV receiver, i am making it 2 channel stereo system so i am talking about dedicated 2ch pre amplifier. any one is using these speaker with dedicated 2ch pre amp ?

I think tube amp can do the better job.

AV receiver, pre-amplifier... Doesn't matter, they should all work. If you like the "tube" sound then go ahead and get a preamp with a tube stage, just don't go too crazy getting some high end audiophile preamp, it's not necessary. Sure, you could plug a McIntosh C2500 tube amp into BL8000s but ehh, the pre would be overkill for those speakers. At the end of the day however, the output will just be RCA pre-outs which the Beolab 8000s will happily accept. 

As mentioned above, in most cases all you need to do is plug into the RCA input jacks on the BL8000 (make sure the switch is set properly) and they will conveniently "self-detect" the audio source powering them on "green" and within a few moments after the music stops off "red - standby". 

Thanks a lot ! Most probably i will go with Tube amp only.

That would depend on the tube preamp. Modern ones will handle the input impedance of a solid state amp well, old ones not so much. The classic Dynaco PAS 2 and 3, for example, expect to see the extremely high input impedance of a tube amp like the ST70 or such, and have severe bass rolloff with the lower impedance of a solid state amp, so don't use a vintage preamp. Modern tube preamps, such as my not so modern Super PAS 3i (a modification of the original PAS 3 circuitry by Audio by Van Alstine), worked fine with solid state amps.

you preamp only.

you preamp only.