If diodes D5 series 1 mohm resistance to the ground
And u11 for S1A, S1B and DA, DB connection
In this paper how jfets tube Q3 conduction? (see the Q3 technical documentation, the biggest GS pinch off voltage of 7.5 V, Q3 D=S pole? D S pole can exchange used? So just meet Vgs is greater than 0 after conducting reverse voltage VDS) Q3 after the triode how to analysis? Zener diode D1 work here? Limit the output of the op-amp? Why not directly connected to Q3 G pole?
