So I’ve been working on a noise/S&H/glide circuit and was having weird oscillations show up.
Was poking around on it this weekend and saw it was happening when an op-amp that was part of the glide circuit had the load potentiometer fully counter clock-wise - i.e. shorted out. This meant that the op-amp was driving the load capacitor directly. I did some searching and found this:
Q. How does capacitive loading affect op amp performance?
A. To put it simply, it can turn your amplifier into an oscillator.
So I went back to Yves Usson’s reference schematic I was cribbing from, and sure enough he has an extra resistor (R4) before the pot to stabilize the whole thing when the pot is fully ccw.
The lesson here is, if Yves does it he has probably done it for a reason and you should do it too.