Hi again,
After several tests changing electronics with the Andra II´s ,
my best results were with a Jadis Pre JPL and a Bel Canto s300.
Since the 300 BCD series has a low input impedance , them need a preamp or spurce with low output impedance and high gain.
The results were outstanding on a 18x23x7.5 room. It´s a very dry room where deep basses are almsot impossible to get.
The BCD + jadis fills the room easily , with nice tones , deep and controlled bass , etc..
The nice thing is that the BCD s300 is cheap and runs cold.
Probably there are better preamps there for this purpose .After trying EAR834 deluxe, JRDG consonance , Spectral dm-6 and my own Audion Premier line the winner was clear .
Since the demanding matching impedance/gain of the BCD and Andra power requirement, the best were obtained through the Jadis .