Thank you. All the tips are well received of course.
Okay, last night I was also thinking about lowering R11even more but I don´t know until what value I can lower it. Maybe 1K ?... I have right now is 1.95K so I'm going to try to lower this value up to 1.5K easily.
I'm thinking about Jim's comment about the total value of R11 + R12. Do I have to compensate R12 obligatorily? On the other hand, change R12 you say that should not significantly affect the plate voltage.