WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Look for mu follower ecl86 preamp, can't remenber the name of the French magazine but i can remenber that someone reported good results in this forum. I may try it some day, have the tubes anyway.