Precision Power Supply / Elektor, December, 1982
@Keno - "Yes, heart of the problem is 100% "the changing of voltage" Right. So stop beating around the bush and tell us what the voltages ARE. And if the 723 voltages are changing, then isolate the 723 section by removing the 3 base drive components (R9, D4 and D5), and find out why the 723 is acting up. Come on, this isn't hard. Isolate the problem section, determine the error, and fix it. Stop beating around the bush with generalities.