I'll have a close look and set about to plan an implementation.

There will undoubtedly arise some questions. I've built lots of simple regulators, some with pass transistors, and some with limiting of one sort or another, but all based on 3-terminal regulators.

I didn't really believe that a serious dual-tracking supply with the properties I desire could be built around three-terminal regulators, though, first, because of the limitations on their supply voltage, and secondly because driving two regulators with a single control voltage, regardless of how well-generated it was, would likely produce different results from different op-amp/regulator combinations. Once one has to start correcting deviations from nominal circumstances, it becomes difficult. That's why I didn't pursue the NSC app-note.

The 42-volt value, BTW, simply came from the rated maximal output of the RC4194.

There is one feature that I didn't mention, but which sometimes becomes quite useful, and that's an offset voltage between the positive and negative supply. Is that an easy thing to provide when it's needed?

RE