Ok, finally I replace R1et R1-1 (1K+1K2) by two 2k2 1W in // and it's works very well. The first test are pretty good. If you want I made a final review when I will finish my Power supply . The odd things is the fact that the transformer need a small charge (not too small - 30mA) on PCB to works well and on Protoboard it not need a charge at all to make 36VDC... Thanks audioguru for your answer !