"I don't simulate. I build the real thing and test."
Show me what you think it needs? (for others if not for me)
The problem is the constant current loop has too much phase shift and gain. I think that 100nF capacitor is in the wrong place. It would be better between pin 1 and 2 of the LM358 and might need to be a larger value. I would simulate the AC/transient response, tweak the capacitor value, build it and tweak it again, if necessary.
I have been trying to see how the circuit works and found I needed to re-arrange it to distinguish each function.
(
I don't mean to offend.)
I believe the datasheet suggests that C
ADJ be 10uF to improve ripple (C2 or C11 in your circuit).
It appears the left LM358 is being used as a comparator instead of an amplifier.
And the right LM358 is to provide a minimum load to the LM338.
You are suggesting that a feedback capacitor (indicated in red) be added to act more like an integrator to slow the leading edge?
I can not figured out which circuit you are referring to?